The Post and Courier (Charleston, SC)
Sinus disease, head trauma can cause loss of smell
By M.R. Hiller
Q: I am 83 years old and have a very poor sense of smell. Do I just write this off as part of getting old?
A: Some degree of smell loss is common at your age. Even so, a noticeable deficit in your sense of smell should not be attributed to normal aging without first considering other possible causes.
Although many animals require a keen sense of smell for survival, the sense is less important in humans. Humans can sense between 2,000 and 4,000 different odors. The number of Americans with an impaired sense of smell is estimated to exceed two million. Many can still smell, but their ability to do so is reduced, a condition referred to as hyposmia (Greek for “low smell”). Some people completely lose their ability to smell and are said to have anosmia (meaning “no smell”).
Smell loss can reduce the enjoyment of pleasant odors and create insecurity because of the possible inability to detect body or house odors.
Perhaps more important, people who cannot smell may be unaware of hazards such as fire, spoiled foods and chemical exposures.
In the home, potentially hazardous gas leaks may go undetected by people unable to smell the warning odorant added to natural gas. In this circumstance, detectors can be purchased to alert patients with smell disorders to elevated levels of natural gas.
The senses of taste and smell are closely connected. True taste is limited to the detection of salt, sweet, bitter, sour and perhaps metallic tastes by the taste buds in the mouth and throat. What many commonly refer to as taste is actually a combination of both taste and smell known as flavor. More then 75 percent of food’s flavor is actually attributed to smell, and most people complaining of taste loss actually suffer only from smell loss.
University of Pennsylvania Smell and Taste Center researchers compared patient complaints with objective taste and smell test results of 750 patients. While 9 percent of patients perceived their problem to be taste loss only, objective testing revealed that only 1 percent suffered from isolated taste loss. Combined smell and taste loss was reported by 58 percent of patients but could only be confirmed in 3 percent of patients. The results of this study were published in the May 1991 issue of Archives of Otolaryngology – Head and Neck Surgery.
Smell and/or taste loss directly reduce the enjoyment of food and may lead to unhealthy dietary habits. Patients may compensate for their deficits by increasing the amount of salt and/or sugar in their diets. This can be particularly detrimental to patients with problems such as high blood pressure, congestive heart failure, diabetes or kidney disease. Appetite can be severely reduced, resulting in decreased food intake and unwanted weight loss.
The causes of smell loss are varied. About 40 percent of the time upper respiratory tract infection or nasal or sinus disease is the cause. Head trauma is also a common cause of smell loss, accounting for 15 percent of cases of hyposmia/anosmia. Other causes of smell loss include medication, smoking, radiation therapy, chemical exposure and neurological diseases such as Parkinson’s disease, Huntington’s disease and Alzheimer’s disease. About 20 percent of the time a cause cannot be identified.
Each year more than 200,000 patients consult a doctor regarding smell or taste loss. Even though the sense of smell usually begins to wane after age 60, complaints of significant smell loss in an older patient warrant proper investigation. Many doctors, especially ear, nose and throat specialists, called otorhinolaryngologists, are capable of evaluating patients who have impaired or lost smell. In addition, there are a handful of medical facilities within the United States that specialize in taste and smell disorders.
Standard evaluations include taking a careful history, linking any viral or bacterial infections to the time of smell loss, executing smell tests, viewing the upper part of the nose with an endoscope and, if other disease are not ruled out, computerized tomography (CT scanning) or magnetic resonance imaging (MRI) may be performed to look for changes within the brain.
Sometimes the sense of smell will return on its own or can be restored by addressing the underlying cause. About one-third of the time treatment requires removing or relieving an obstruction or treating an infection. If nasal polyps are present, they can be surgically removed but often recur. Even when smell loss is not amenable to treatment, patients benefit from counseling regarding healthy dietary strategies to compensate for flavor loss, underlying illness and the likelihood of spontaneous improvement.
The National Institutes of Health provide support to the following clinical centers:
Los Angeles Times
May 17, 1994
Tracking the Scent; A Sniff Can Turn You Hungry or Warn You to Run. Dr.
James Evans is Studying Why Some People's Sense of Smell Stinks
By Patrick Mott
It only happens now and then, and only for a few precious seconds: the quickest whiff of blooming flowers, of coffee brewing, of bacon grilling, of freshly cut grass. Then, nothing. No smells at all. Not noxious odors, not glorious, evocative scents.
That’s what it’s like for Toni La Motta of San Diego. One tantalizing perception, then her olfactory mechanism, for some reason, shuts down. It’s been like that, she says, since high school, more than 30 years ago.
And, until recently, she never found a doctor who seemed to care.
“It’s very annoying to me that the medical profession has ignored it,” La Motta said. “It’s like it’s really not an issue. Most doctors, when you tell them you have no sense of smell, say, ‘So what? Live with it.’”
But not Dr. James Evans of UC Irvine. Instead, Evans will seal you inside a dark, soundproof cubicle, stick electrodes all over your head, wire you up to a lab full of computers and diagnostic gizmos, stick a plastic tube into one of your nostrils and blow various scents into your nose.
Evans, an assistant professor of neurology and the director of the Chemical Senses Clinic at UCI, is out to help people such as La Motta smell the roses.
Since 1987, Evans has been researching the brain triggers (he calls them “olfactory-evoked potentials”) that allow us to distinguish smells; about a year ago he developed an intricate and highly sensitive system to measure olfactory perception. In recent months, he has used the high-tech system to measure olfactory and neurological responses in some 70 test patients, from head injury victims to allergy sufferers to victims of neurological disease to even more mysterious cases such as La Motta’s.
Through his research, Evans hopes to identify more accurately the causes for loss of smell (and, by extension in most cases, loss of the sense of taste) and develop methods to treat them. It can, he said, be a mysterious process, but he has at least one biological advantage. “One of the interesting things about olfactory nerves,” Evans said, “is that they die and regenerate regularly.” This means that in some cases of loss of the sense of smell, it may be possible to stimulate the growth of olfactory nerves and thereby resurrect that sense.
In Evans’ lab, he and a group of assistants are refining techniques to differentiate between loss of sense of smell because of trauma to the olfactory nerves (such as a head injury) and loss because of inhalation of toxic substances, or because of allergies or possibly because of neurological disorders such as Alzheimer’s disease. These diagnostic techniques range from measurement of brain activity to the Jelly Belly test.
The Jelly Belly test is actually an informal demonstration of how the olfactory receptors, which are in the upper part of the nose, work.
Evans offers a visitor two or three Jelly Bellies (a popular, small and highly flavorful variety of jelly beans) and asks the visitor to pinch his nose before popping the candy in his mouth. The result: a vague sense that something sweet is in the mouth but there is no discernible taste. However, once the nostrils are released, there is a sudden burst of taste: strawberry, coconut or grape.
This is, Evans said, one way to gauge what is known as “conductive loss” (odors can’t reach the olfactory receptors) and “general loss” (in which the olfactory nerves have been sheared in an accident).
Dorothy Cotton, an 83-year-old test subject from Newport Beach, said she suspects that her inability to smell may be tied to conductive loss.
“It came on slowly,” she said, “and I think it may be tied with my sinuses. It’s been at least 15 years that I haven’t been able to smell.”
In the lab tests, she said, she still could smell nothing. However, she said, Evans recommended she take zinc supplements for two months, discontinue the nose drops she was using and substitute antihistamines to clear her sinuses. Zinc, explained Evans, can be depleted by certain types of viruses that can also affect smell.
“I can taste sweet and sour and salty on my tongue, no problem,” Cotton said after starting the zinc treatments. “But if you blindfolded me I wouldn’t know what I was eating. You learn to appreciate some foods by the sight of them, but eating is a pleasure. I would give a lot to have my taste working again.”
Another rather low-tech test in the lab is called “forced choice,” in which patients are given two small squeeze bottles, one imbued with an odor and the other odorless, and asked to identify the one with the odor. The odors are not all the same strength, however, because researchers have found that “the smelling scale (is) analogous to the decibel scale,” Evans said.
That is, just as there are degrees of deafness, Evans said, one person may be able to smell an odor only in a strong concentration, while another may be aware of it in its weakest strength. For instance, a low concentration of amyl acetate smells like bananas to a subject with healthy olfactory apparatus, while a very strong concentration can smell like airplane glue.
“At different concentrations they have different qualities,” said Evans, “from quite noxious and foul to quite pleasant.”
It has been found, Evans said, that some people suffer from a condition called “specific anosmia,” a kind of olfactory color blindness in which the person cannot smell certain smells but can perceive most others. To test for this, the lab stocks a catalogue of more than 50 aromas.
“There may be no genetic receptor in a person for a certain class of odors,” Evans said. “And it appears to run in families. There are about 150 types of odor receptors, which means that we can identify that many classes of smells.”
Unless something goes wrong. Then patients may find themselves attached to the most advanced of Evans’ testing apparatus.
The entire system measures olfactory evoked potentials (OEP)—brain activity in response to stimulus of olfactory receptors in the nose. Evans said he developed the technique of measuring OEP in rats at UCI in 1987 but has been using the present system, which he also developed for about a year on various human test subjects. At its most basic, the system involves nothing more than air and smell. It’s the measuring that elevates the process.
It works like this: The patient is fitted with several scalp electrodes to measure brain activity and is plugged into a console inside a dark, soundproof booth (the only stimulus Evans wants is through the nose). A small plastic nozzle is fitted into one nostril, and a gentle stream of air is directed through it into the patient’s nose.
For the most part, the airstream is clean. But at intervals, a machine outside the booth emits a click. This means that for 4/100 of a second, what Evans calls “a pulse of odor” is introduced into the stream. Computers measure any brain wave activity that occurs at that instant.
This entire process allows Evans and his researchers to locate, among other things, the possible source of loss of brain response.
Treatment, Evans said, depends on the cause. In the case of a head injury, the nerves may regenerate on their own, or there may be no hope for treatment. Sometimes, he said, traditional respiratory therapy can bring back some function. Polyps, benign growths, allergies, swelling, infections, sinusitis—all can be treated to different degrees.
However, he said, matters become more murky when patients are affected by neural degenerative diseases such as Alzheimer’s disease, Parkinson’s disease and Korsakoff’s psychosis (seen in alcoholics).
“Smells will bring back strong memories to you,” Evans said, “and all of these diseases are associated in some way with memory loss.” Partly because of this, he said, “olfactory loss may be one of the first things to go” in a patient suffering from such diseases. Research is continuing into drug therapy for neural disorders, and Evans called the work “promising.” However, the tie-in remains a mystery.
Depression is common among people with loss of smell, said Evans, although he added that “after years, many resign themselves to it and find ways of stimulating what receptors they have with salt and spices.” Still, there is yet another factor to consider: safety. Without a sense of smell, fires and natural-gas leaks can go unnoticed. La Motta knows this.
“I remember an incident in high school,” said La Motta, a 48-year-old writer and teacher who participated in Evans’ research, “when we were doing a hydrogen sulfide experiment, and I couldn’t smell anything in the lab.” Later in life, she said, “I’d be in the living room and there would be smoke all over from the kitchen. I’d be reading and absorbed and not even notice. One of my major problems today is that I burn things frequently in the kitchen.
“There are some times when it’s scary, especially if I leave the house and don’t know something’s burning. And the (cat box) is worrisome. My friends have to tell me to change the (cat-box filler).”
During her testing at UCI, La Motta said she “felt” the smell in her nose during her time in the booth but didn’t actually smell it.
“It was fascinating to me, though, because he was actually measuring it. I’ve been through acupuncture, to several doctors. They all said they can cure it, and nobody has. I hope this time it’s different.
“People joke with me all the time and say I’m lucky, but I don’t see it. I can’t smell roses or the spring or the ocean.”
How Sense of Smell Works
Most people can distinguish thousands of different odors, whether foul or fragrant, with a simple sniff of the nose. For people without a sense of smell, food doesn’t taste as good, flowers and perfume evoke no special memories, and potential hazards signaled by noxious odors go unnoticed.
1. Airborne molecules of a rose travel through nasal passages.
2. Molecules dissolve in mucous membrane.
3. Receptor cells are stimulated, then generate nerve impulses.
4. Nerve impulses travel through olfactory nerve to the olfactory bulb.
5. Olfactory bulb analyzes impulses and sends them to brain, which identifies the smell.
A Perfect Match
Scientists believe the smell process occurs when there is a physical connection between odor molecules and receptor sites. Bleach molecules, for example, would only fit with receptors on some cells, while the odor molecules of a rose would only fit on receptors on the other cells.
The Post and Courier (Charleston, SC)
December 20, 1994
Cadmium can hurt sense of smell
By M.R. Hiller
Q: I’ve become increasingly aware that from time to time my sense of smell isn’t good. I am 38 years old, and in addition to frequent sinus infections that may cause a loss of smell, I work in a refrigerator coil manufacturing plant that exposes me to cadmium. Can cadmium cause smell impairment? What other causes are there for smell loss?
A: An association between some degree of smell loss and cadmium, metal used in a variety of industries, was first reported in a 1948 study of alkaline battery workers. Since that time several other studies have concluded that cadmium can seriously impair the sense of smell. But there are over 200 conditions and medications that can cause smell loss, studies show.
Many doctors, especially ear, nose and throat specialists, called otolaryngologists, are capable of evaluating patients who have impaired or lost smell. In the United States, a handful of medical facilities specialize in this area.
About 2 million people in the United States suffer from some degree of loss of smell and about 200,000 patients go to their doctors for this problem. Total anosmia refers to the complete loss of smell, and partial anosmia describes the inability to smell a particular odor. Hyposmia is the reduced ability to smell all or select odors.
Although animals often require a keen sense of smell for survival, the sense is less important in humans. Still, without smell, danger exists from not being able to detect smoke or gas odors or rancid food. Social habits may also suffer. Without the ability to smell, a person may feel insecure about not being aware of body odor or house odors. And since over 75 percent of food taste is actually attributed to smell, the enjoyment of food is diminished.
Studies show that about 20 percent of smell loss is caused by upper respiratory viral infection; 15 percent by head trauma; 20 percent by nasal and sinus disease, including polyps; 20 percent by unknown causes; 20 percent by other causes such as systemic diseases like Parkinson’s; and about 5 percent by chemical exposures—such as to cadmium, mercury, lead and hydrocarbons—and medication.
Cadmium is a metal found widely in industry and in the environment. The National Institute for Occupational Safety and Health (NIOSH) estimates that 100,000 American workers are exposed occupationally to cadmium fumes or dust in such industries as electroplating and battery manufacturing and as a component of pigments, plastics and metal alloys. Sources of cadmium contamination in the environment include fossil fuel combustion, municipal waste incineration, sewage sludge and phosphate fertilizers.
Cadmium that is either inhaled or ingested accumulates mainly in the kidneys and liver.
One study at the Medical College of Virginia in Richmond, Va., examined 55 workers from a refrigerator coil plant.
In this study, Dr. Cecile Rose, professor of medicine, found that 13 percent of the workers had either moderate or severe reduction in the sense of smell, 44 percent had a mild loss and 43 percent were normal. Rose also found a correlation between the severity of smell loss and kidney damage and speculated that smell loss may be an early warning sign of kidney damage. These findings should spur efforts to prevent ongoing exposures that lead to hyposmia and anosmia, writes Rose. The study appeared in the June 1992 issue of Journal of Occupational Medicine.
Since smell loss as a result of occupational chemical exposure is often transitory and reversible and millions of Americans each year suffer from occasional sinus infections, which may cause some temporary loss of smell but eventually clear up, it’s not always obvious when help is needed. Some experts believe a smell loss that persists after all the nasal passages are clear from congestion is unusual and may warrant a visit to a doctor, while others don’t worry about waiting months. The Medical Adviser is produced by the Palo Alto Medical Foundation using a data base that contains articles from more than 3,500 medical journals around the world. Send your questions to the Medical Adviser in care of this newspaper. For a fee, the Palo Alto Medical Foundation will conduct a personalized medical literature search. For information, call 1-800-999-1999.
The New York Times
February 14, 1995
Powerhouse of Senses, Smell, at Last Gets its Due
By Natalie Angier
On this, the authorized day of passion and romance, when one tries hurriedly to spark a new flame or fan an old one back to life, when a wooer would prefer not to beat around the bush of love but rather dive right into it, the best Valentine’s gifts may indeed be the staples: a dozen fragrant roses, a box of fine chocolates, a bottle of French perfume. After all, these items became shorthand for love by appealing shamelessly to the second-sexiest organ of the body—the nose.
Seeing may be believing and hearing may be music to the ears, but a good smell sails express nonstop to the deepest, warmest, happiest and most voluptuous sector of the self. And nothing can evoke a time, a place, an emotion past better than an aroma.
When Marcel Proust slipped into an eight-volume, orgiastic memory trance after eating a madeleine, it was not the little cake’s taste that set him off so much as its smell. The tongue can distinguish only a handful of different inputs: sweet, sour, bitter, salty and possibly monosodium glutamate; detecting other flavors is a nose job.
Those who doubt the importance of smell to taste should try eating food while holding their nose, an exercise that will leave them utterly unable to distinguish a carrot from an apple, a Belgian truffle from a drugstore Brach’s.
Like all mammals, humans can discern perhaps 10,000 or more odors. Smell is essential for most forms of human congress, particularly the most intimate forms. An infant finds its mother’s nipple through the sense of smell, and a mother in turn can pick out her newborn based on its scent alone. A couple can survive all sorts of differences, notes Dr. Susan S. Schiffman, a professor of medical psychology at Duke University Medical Center, but if one dislikes the other’s smell, the relationship is doomed. Many people prefer not to leave their private odor type to chance alone, which is why the perfume industry is a $6 billion-a-year enterprise. At the same time, the popularity of nouveau wellness techniques like aroma therapy is blooming.
As much as people recognize the profound role that smell plays in their affairs, the sense traditionally has not been taken seriously. “People snicker when they hear I work on smell,” said Dr. Gary K. Beauchamp, director of the Monell Chemical Senses Center in Philadelphia. “They’re also embarrassed by it.” When patients complain of losing their eyesight or hearing, doctors pay attention; talk of a waning sense of smell, and doctors may joke that at least the subways will be more bearable.
Lately, however, the science of smell has been making enormous strides, propelled largely by the recent discovery that mammals recognize odors through the grace of a thousand or so distinct odor receptors located in the nerve tissue of the nasal cavity. The receptors are proteins that snake through the membranes of sensory nerves found in the so-called olfactory epithelium, a patch of tissue the diameter of two pencil erasers sitting right behind the bridge of the nose. Researchers believe that when an odor molecule floats through the air or is pushed upward from the throat during chewing or swallowing to meet the appropriate membrane receptor in the nose, the receptor changes shape and thus alters the property of the nerve cell. That change then prompts the nerve to fire a smell signal backward toward the brain.
The announcement of this giant family of odor receptors in 1991 was greeted with fanfare and surprise, for few had expected the smell system to be so elaborate and ungainly. The visual system, by contrast, can make out many thousands of hues through the use of just three color receptors, one tuned to red, another to blue, a third to green.
In the last four years, researchers have learned a great deal about how the odor receptors are distributed in the nose, how they are connected to the smelling centers of the brain, and how the receptors might operate singly or in teams to allow a person to discriminate between the scent of an orange and that of a lemon, a Crayola crayon and a bit of ear wax, a roasting loin of pork and a kitchen curtain that has caught on fire.
In several recent papers appearing in the journal Cell, Dr. Richard Axel, Dr. Robert Vassar and their co-workers at Columbia University College of Physicians and Surgeons in New York and Dr. Linda B. Buck and her colleagues at Harvard Medical School in Boston independently described how odor information traveling from the nose to the brain becomes increasingly organized and refined. The detection of an odor begins with an arousal of smell receptors distributed more or less randomly within the nasal cavity. The information from those receptors is then focused onto elegantly structured “smell maps” within the all-important olfactory bulbs, which are a pair of blueberry-sized structures that serve as the relay center between nose and brain.
By studying the smell apparatus in rodents, the researchers have determined that each nerve cell in the olfactory epithelium holds only one type of receptor, but that there are many thousands of every type of nerve fiber—and thus of every type of receptor—scattered across the epithelium. But when those nerve cells send their connecting wires, or axons, back to the olfactory bulbs, all the axons projecting from the same class of fibers end up hitting a single node in one of the bulbs. In that way, the relative chaos of the odor-collection mechanism is reduced to military neatness of information within the bulbs.
The biologists also presented a model in which the smell system operates roughly like the immune system. According to this notion, the body confronts a new odor as it does a new microbe, that is, piecemeal. In attacking a pathogen, the immune system generates many different antibody proteins, each able to fix onto a small region of the enemy. So, too, might the smell system consider an odor from multiple angles, with one receptor recognizing one chemical signature of the odor molecule—say, a fatty acid chain of a particular length—while another receptor tunes in to a slightly different segment of the odor. The brain then synthesizes the disparate bits of information into a coherent label that experience has recorded as, for example, “smell of new plastic doll.”
In other words, Dr. Buck said, there is probably no lemon-specific or rose-specific receptor in the nose. Instead, the smell of lemon is represented by the activation of a characteristic and presumably small series of receptors. And though similar odors probably stimulate overlapping groups of receptors, the patterns will vary enough to allow a person to distinguish among the lemon smell of a real lemon, the fake lemon scent of a gum drop, and the version found in a lemon shampoo. With a thousand receptors to mix and match, the possible combinations for detecting smells are stupendously large, Dr. Axel said, amounting to 10 with 23 zeroes after it. However, he added, the human brain lacks sufficient neural connections to discriminate among that many odors, and so evolution has winnowed the network down to concentrate on classes of odors likely to have been relevant to ancestral human affairs, when the hominid nose was hammered into shape.
Thus, while the human odor-detecting apparatus is impressively versatile, able to pick up many new scents it has never confronted before, it cannot sniff out everything, including some common toxins that one might wish smelled as noxious as they are—carbon monoxide and natural gas, for example. Moreover, a human’s olfactory might is 10 to 20 times less sensitive than that of a dog, and dimmer still than that of a rat.
Although much of the groundwork had been laid by electrophysiologists, anatomists and psychologists, the new molecular approach to studying smell has galvanized the field and given it a trendy cachet. The smell system offers researchers a unique window onto the brain. Unlike other nerve cells, which cannot regenerate, olfactory neurons die and are replaced throughout life, and scientists would love to learn how the smell cells accomplish what eludes the constituents of the spinal cord or neocortex.
The linkup between nose and brain likewise holds considerable interest. The olfactory bulbs extend some of their axons directly into the limbic system of the brain, the celebrated seat of emotions, sexuality and drive. Odor information thus goes from nose to bulbs to limbic system, a much more direct route than that traversed by visual and auditory input. Olfaction may be an ancient sense, perhaps the hoariest of them all; but its wiring to the brain is sweet and pithy.
Beyond illuminating the mechanism of smell, the new research may prompt greater appreciation and respect for the most neglected of the five senses. For other animals, smell reigns supreme.
If a female boar is ovulating, and she is given a sample of a male boar’s urine to sniff, she will raise her haunches in anticipation of being mounted. Cats scent-mark their territory by releasing odor molecules from glands in their eyebrows, rumps and the pads of their paws.
Reporting in the current issue of the journal Science, an international team of researchers demonstrated that when they altered the smell center of a male fruit fly’s brain, the fly became bisexual, approaching male and female flies with indiscriminate ardor. The flies had very likely lost their ability to smell the signal that males emit to ward off other males.
Recent work from scientists in Belgium and at the Johns Hopkins University indicates that even sperm may rely on a kind of smelling method for wending their way toward an egg. Sperm cells turn out to bear on their surface the same odor receptors stippling the nerves of the olfactory epithelium.
Throughout the animal kingdom, the sense of smell is the link to life. “There are strains of mice that are blind and you would never know it from their behavior,” Dr. Beauchamp said. “But there would never be a strain that couldn’t smell. Such a mouse would not find food or a mate, and it would not persist.”
Among humans, smell is perhaps less important for bodily survival. In fact, there are huge numbers of people who are anosmic, who lack a sense of smell, either from birth or following a head injury. Ben Cohen, a co-founder of Ben & Jerry’s Homemade Inc., has said he is anosmic, which is why his ice cream is so rich in tactile and other sensory characteristics beyond flavor alone.
Yet while a lack of sense of smell may not be fatal, it can be depressing. “We had a patient in here who hit his head recently and lost his sense of smell,” Dr. Schiffman said. “He’s quite unhappy, he doesn’t feel like eating, and he’s lost 10 pounds.”
As people age, they almost invariably suffer a decline in their sense of smell; developing a taste for spicy foods late in life is not unusual. Spicy food, stimulates odor receptors, as all food does, by traveling from the back of the throat up to the olfactory epithelium. More to the point, it also has a “kick” that excites the trigeminal nerve, which controls the muscles of the face and jaw. Horseradish, alcohol, menthol—all have this tingly, so-called chemesthetic component that is independent of taste and smell, said Dr. Charles J. Wysocki of the Monell center.
As bad as anosmia is, sometimes being able to smell can be even worse. A persistent bad smell can be more debilitating than even the continuous cry of a car alarm. Dr. Schiffman and her colleagues are now studying a group of people in North Carolina who live downwind of hog farms. “They constantly have fecal odor in their kitchen and on their drapes,” she said. “They can’t open doors or windows.”
“We’ve done profiles of their mood states,” she added, “and we’ve found they’re severely depressed, anxious and have less vigor.”
Interestingly, though, what is foul and what is fair may depend largely on training. There are few smells that people universally rate as either good or bad.
Most cultures celebrate the sweetness of flowers, but people who work in the funeral business come to associate the odor with death and decay. Adults find the smell of feces to be highly objectionable, but young children do not, and perfumes are known to have their “fecal notes.”
Skunk odor may be unbearable in high concentrations, but many consider a faint whiff of it to be almost pleasant. Skunk smell is not terribly different from the odor of musk and civet, essential ingredients in perfume that were originally isolated from glands in the abdomen of the male musk deer and near the anus of the African civet cat.
As it turns out, one of the only scents that appeals to people around the world and of all ages is the aroma of cola, prompting some scientists to suggest the cola preference may be innate. That could explain why, no matter where one wanders, no matter how remote the locale, a bottle of some variety of cola is never far from view.
Chattanooga Free Press (Tennessee)
September 9, 1997
The Medical Adviser; Cause Determines Treatability of Smell Loss; About
2 Million People in the United States Suffer from Complete Loss of Smell, Called
anosmia, or Partial Loss
By M.R. Hiller
Q: Over two years ago I suffered a mild head injury. I recovered nicely and seem to have no residual effects. Three months ago, following what seemed to be a simple cold, I noticed that I couldn’t taste or smell well. My food is nearly tasteless, but I can still smell my cleaning ammonia. I’ve gone to several doctors who aren’t certain what is causing the problem. My current doctor believes this is related to a bad case of allergies and not the head trauma. This bland life is starting to drive me crazy. Can I be treated? –D.T., Miami
A: Certain causes of loss of smell, such as nasal congestion or growths in the nasal passages, can often be treated successfully. However, if the olfactory nerves are damaged, smell loss is often permanent and untreatable. A person can have complete loss of smell and still react to ammonia. Finally, although head trauma can cause smell loss, four months is the longest time reported between a head injury and the start of the loss.
Many doctors, especially ear, nose and throat specialists, called otolaryngologists, are capable of evaluating patients who have impaired or lost smell. In the United States, a handful of medical facilities specialize in this area.
About 2 million people in the United States suffer from complete loss of smell, called anosmia, or partial loss. Every year about 200,000 patients go to their doctors complaining of smell loss.
Although animals often require a keen sense of smell for survival, the sense is less important in humans. Still, without smell, danger exists from not being able to detect smoke or gas odors or rancid food. Social habits may also suffer. Without the ability to smell, a person may feel insecure about not being aware of body odor or house odors. And since over 75 percent of food taste is actually attributed to smell, the enjoyment of food is diminished.
Loss of smell is particularly prevalent in older people, and nearly 75 percent of those over age 80 have some loss. Other than normal aging, over 200 conditions and medications can cause smell loss, studies show.
A study at the University of Connecticut Health Center in Farmington looked at these causes. It found that 19 percent of smell loss was caused by upper respiratory viral infection; 14 percent by head trauma; 21 percent by nasal and sinus disease, including polyps; 22 percent by unknown causes; 3 percent by chemical exposures and medication; and 21 percent by other causes, such as systemic diseases such as Parkinson’s. The findings were reported by Dr. April Mott, director of the university’s Connecticut Chemosensory Clinical Research Center, in the journal Medical Clinics of North America.
Since millions of Americans each year suffer from occasional sinus infections, which may cause some temporary loss of smell but eventually clear up, it’s not always obvious when help is needed. Some experts believe a smell loss that persists after all the nasal passages are clear from congestion is unusual and may warrant a visit to a doctor, while others don’t worry about waiting months.
Identifying the cause of smell losses has improved over the last 10 years. “The days of pulling stale coffee grounds off the shelf and whisking them under a patient’s nose to evaluate sense of smell are over,” writes Dr. Allen Seiden, chemosensory researcher at the University of Cincinnati College of Medicine. “There are now well-established and proven methods for evaluating both taste and smell loss.”
Standard evaluations include taking a careful history, linking any viral or bacterial infections to the time of smell loss, executing smell tests, viewing the upper part of the nose with an endoscope and, if other diseases are not ruled out, imaging the area with computerized tomography (a CT scan) or magnetic resonance (MRI).
In the few cases where an underlying disease is causing smell loss, treatment options include treating the disease. In about a third of the cases, treatment requires removing or relieving the obstruction or treating the infection. Therapies with antibiotics and nasal corticosteroids have been shown to be effective; however, steroids are known to cause problems, so long-term use is generally not advised. Polyps can be removed surgically, but recurrence is high.
“Patients with smell loss find it very important to get answers to their problem. Sometimes we get patients who have been looking for answers for more than a decade. They’ve gone from doctor to doctor, received treatment after treatment. Even if their condition is not treatable, we, and other chemosensory centers, can at least provide them enough answers to stop spending their time and money needlessly,” said Dr. Mott in an interview.
The San Francisco Chronicle
December 2, 1997
The E-Nose Knows; Electronic sniffers can do many jobs
By Peter Sinton
Coors beer, Evian water and Starbucks coffee use it to test beverage quality. Gallo Winery has researched whether it can spot bad corks. Lancome is using it to ensure consistency in its cosmetics products.
What’s “it”? Electronic noses.
Thanks to breakthroughs in organic chemistry and electronics, scientists have devised sophisticated sensors and computer “neural networks” that can create a digital fingerprint of a smell.
Unlike electronic eyes, electronic olfaction and e-noses may not be part of most people’s vocabulary. But they soon could be.
The applications are wide-ranging. Artificial sniffers can be used to make sure industrial chemicals, packaging materials and other ingredients meet quality control specifications.
They also might be used to ensure the freshness of food, drinks and beauty aids. Or they could be used to monitor pollution and exposure to chemicals; spot explosives and drugs; and even discover counterfeit products and diagnose diseases.
To be sure, the industry is still in its early stages of development. The first generation of electronic noses may be unable to differentiate the 700 or so different chemical vapors in a glass of beer. But they have some advantages.
They can work 24 hours a day. They never take vacations or get colds. And they don’t suffer anosmia (smell blindness) when exposed to aromas for long periods of time.
John Lasch, vice president for business development at Cyrano Sciences in Pasadena, points out another plus for electronic sniffers: “Human odor panels are very expensive to employ and they can get quite subjective.”
Still, human noses are more discriminating than the first man-made models. Humans have about 10 million smell receptors in their noses, while dogs have about 10 times that number.
By contrast, electronic noses have an array of one or two dozen sensors that track different components of smell. Using a variety of technologies from polymer sensors that swell when they detect molecules in the air to metal oxides that react differently to various aroma components, patterns are mapped and logged into a computer’s memory bank.
Most companies that are testing electronic noses, or using them in the workplace, are not anxious to talk about it for competitive reasons.
French-owned Alpha Mos, which has a U.S. base in Belle Mead, N.J., has sold about 150 of its $ 50,000 to $ 100,000 electronic noses.
Named “Fox” because it is both clever and smells well, Alpha Mos’s electronic sniffer is used by Evian to test whether chemicals are leaching out of plastic bottles into its water.
Cosmetic maker Lancome is using Fox to assure consistency of essential oils and could use it to protect its brands from imitators.
In the United States, Cincinnati’s Tastemaker is using it to check raw materials like pineapple concentrate. The U.S. Agricultural Research Service is evaluating it, as are Starbucks coffee and Coors beer.
E.&J. Gallo Winery has tested Alpha Mos’s nose, too. The technology is not discriminating enough to tell a premium from a jug wine. But it might detect the chemical byproduct of the Brettanomyces mold that attacks corks and causes wine that comes in contact with it to turn musty.
Although corks only cost a few cents each, Gallo Marketing Vice President Patrick Dodd said that 2 to 4 percent of them can be tainted. Economic losses can be substantial if they are not spotted and bottled wine has to be tossed.
While food and cosmetics represent a growing market for electronic noses, the biggest market remains quality control for the chemical, plastics and paperboard industries.
Britain’s Neotronics Scientific, which branched from gas detection equipment into electronic sniffers eight years ago, sells most of its eNose products for industrial packaging applications. But it also is being used to test the quality of propylene glycol in lotions and ammonia levels, which can indicate freshness, in frozen shrimp.
AromaScan, another British company with a U.S. base in Hollis, N.H., claims to be the world leader in digital aroma technology with 200 of its $ 30,000 to $ 70,000 noses operating around the world. An AromaScan machine reportedly is installed on the Mir space station to detect odors from failing electronic components before the crew notices.
Although the company began selling to the food industry three years ago, AromaScan’s machines still are primarily used to make sure raw materials meet standards.
“They can pick up parts per billion and create an aroma fingerprint,” said AromaScan general manager Peter Debrocczy. The equipment, though, is bulky and works best in a controlled setting.
By contrast, Cyrano Sciences, named after the French fictional character with an outsized nose, aims to produce more versatile noses. The company was formed last April with $ 3 million of venture capital financing to commercialize technology licensed from the California Institute of Technology.
The company’s prototype sensor is a bit bigger than a handheld calculator, but in several years Cyrano hopes to produce a nose the size of a computer chip packed with thousands of sensors that might cost only a few dollars each.
“We intend to build a company that addresses a wide range of applications,” said Cyrano’s Lasch. “If there’s a spill, you could wave (an electronic nose) at the material and tell if it’s benzene, hexane or water.” Or it might be mounted in subway stations or other public places to spot toxic gases or other noxious compounds.
Cyrano has a contract with the Department of Defense to develop an electronic nose to detect land mines.
Electronic noses of the future also might be deployed at airports and other places to sniff out drugs and explosives. Cars could be equipped with sensors to track burning oil or leaks. Artificial sniffers even have the potential to spot cirrhosis of the liver by smelling someone’s breath or find other maladies like melanoma.
For the moment, however, the market for artificial sniffers is only a few million or tens of millions of dollars a year. Not only are electronic noses a bit bulky and expensive, they are not foolproof. For instance, accurate readings with some of the technologies can be thrown off by changes in humidity.
But in the future you are likely to encounter electronic sniffers where you work or shop.
NCR Corp. owns the patent on a new type of scanner that creates a pattern for fruit and vegetable scents. Checking the contents of a consumer’s shopping basket against a reference list, supermarket scanners someday could automatically register the name and price of your produce.
Air-borne molecules dissolve in nasal mucus and stimulate the hairlike endings—cilia—of receptor cells. These receptors generate nerve impulses to the olfactory bulb. The signal then goes on to the primitive part of the brain (limbic system) that governs emotions, behavior and memory. The signals are recognized in the outer layer of the brain (the cortex) where conscious thought occurs. There is no receptor or part of the brain that recognizes specific smells, like a rotting fish. Rather, the brain associates certain patterns with aromas.
Electronic noses use arrays of sensors that measure specific molecules contained in vapor. There are several technologies that are being used to measure the chemical components of smell.
Cyrano Sciences of Pasadena has developed a “nose” that uses electronic sensors that are grain-of-rice-sized pieces of polymer (plastic) packed with graphite particles that absorb chemicals like a sponge absorbs liquids. As the polymer expands, it alters electrical resistance, which creates telltale patterns that can be measured. By using an array of sensors with different polymers, each one reacting differently to the chemical components, it is possible to profile different odors. An artificial neural network (or computer) can memorize this signature, or fingerprint, and identify it when it “smells” it again.
December 12, 1997
Ask Dr. H: What causes an inability to smell or taste?
By Dr. Mitchell Hecht
Q: For the past several months, I’ve been unable to smell or taste anything. What can cause this? –M. Hudson, New Orleans
A: You actually have a single problem—not two separate ones. You see, the complicated process of smelling and tasting begins when molecules released by the substances around us (like the aroma of freshly-baked bread) stimulate special nerve cells in the nose, mouth or throat. These cells transmit messages to the brain, where specific smells or tastes are identified. If your sense of smell is faulty, you can’t taste things very well. For example, did you ever notice that when you have a cold, foods taste pretty bland?
The loss of smell is called anosmia. Some people are born with it—in the same way some people are born deaf or blind. But most people with anosmia acquire it.
It can be caused by a number of things: physical damage (like breaking your nose or concussions); disease (colds, flu and other infections); inhalant abuse (cocaine use, chemical fumes, or smoke damage); advanced age (especially in Alzheimer’s disease); recurrent sinus disease; ong-term smoking; tumors and polyps of the nasal passages; long-term diabetes; and rarely, brain tumors.
A person with a faulty sense of smell and taste is deprived of an early warning system that most of us take for granted. Smell and taste alert us to fires, leaking gas, poisonous fumes and spoiled foods.
Can anything be done to help? Well, if you’re a smoker, it would be a good time to quit. Certain medications can affect your sense of smell (and taste); others, particularly allergy medications and nasal steroid sprays, seem to help allergy sufferers regain what they’ve lost. In many cases, nasal polyps can be surgically removed to restore airflow to the receptors in the nose and can correct the loss of smell and taste.
I’d suggest that you see an ear, nose and throat specialist for a complete workup. You may have a treatable and reversible condition. But if you learn that it’s not reversible, take heart in knowing that you’re not alone. Several million Americans have a problem with smell or taste.
One important point of safety: If you have impaired smell, you can’t detect the odor of natural gas. I’d strongly advise you to purchase a gas detector for the home, as well as a carbon monoxide detector.
The Independent (London)
March 8, 1998
Science: Smelling Faults; Soon an electronic nose could be used to sniff out a range of illnesses from schizophrenia to lung cancer to cirrhosis of the liver.
By Hugh Aldersey-Williams
SCHIZOPHRENIA is the greatest single drain on health resources. It may affect just one person in 100, but it can be a lifelong illness, and costs pounds 1.5bn annually. Yet there is no drug-based cure and no clinical diagnosis for this illness.
Schizophrenia and a range of other mental disorders are thought to be triggered by biochemical imbalances. These imbalances also alter the composition of exhaled breath and body secretions and physicians as long ago as the 18th century noted the anomalous breath odour of patients who would today be described as schizophrenic. Reports to this effect appear in the medical literature up to the first half of this century. But, following the Second World War, increased standards of hygiene discouraged such observations. Now, scientists believe that this lost skill may be regained and improved in order to provide a diagnostic tool for schizophrenia.
“We went recently to Romania, and there it’s part of the routine teaching that people should recognise the smell of schizophrenia,” says Dr Iain Glen of the Highland Psychiatric Research Group (HPRG) at Inverness’s Craig Dunain Hospital. “Here, medical students are seldom taught about it. There have been attempts to isolate the smell of schizophrenia from sweat, but, until now, not using recent technology.” Now, new analytical techniques are making it possible to accurately identify chemicals present in minute amounts. The HPRG, which has already developed a promising skin test, is now involved in a multi-disciplinary collaboration with Scotia Pharmaceuticals and odour- sensing technology pioneer, Dr George Dodd, to develop a powerful and versatile breath test.
The HPRG’s research so far has shown that the nerve-cell membranes in schizophrenics are deficient in two acids—arachidonic acid and docosahexaenoic acid. “If there is a loss of arachidonic acid, where is it going?” asks Dr Glen. “We think it is being oxidised and going into the breath.” Ethane and pentane have been detected on the breath. Other researchers have shown that levels of the enzymes that convert these acids into prostaglandins are high during acute periods of illness. In 1996, it was found that a gene associated with one of the enzymes had abnormal forms in schizophrenia patients. Both environment, through the intake of unsaturated fatty acids, and genetics play their part. The picture was complete.
It has taken the HPRG team 15 years to get to this stage, and to overcome scepticism from the medical community, to get smell accepted as a diagnostic tool for schizophrenia. The Scottish researchers recently obtained their first government funding to continue their work towards a clinical diagnosis and possible drug treatment of the root causes of the disease. “The skin test has produced major interest,” says Dr David Horrobin, director of Scotia Pharmaceuticals and president of the Schizophrenia Association of Great Britain. “Patients, too, are fascinated. They say, ‘I always knew it wasn’t all in my head.’ For many, it’s an immense revelation to see a skin test on their forearm. But the breath test is potentially enormously more sophisticated. It can give you answers potentially to many more diseases.”
Construction started last month in Inverness on the breath-test apparatus. This is a modification of technology originally developed by the US Environmental Protection Agency to test for contamination by organic chemicals in industry. “We’re talking about picograms million-millionth parts of a gram in the breath, so we needed a technology to detect molecules at very low levels,” says Dr Glen.
For the patient the experience is much like using a breathalyser. In the laboratory, the stored breath sample is heated to liberate the breath constituents which are then separated using gas chromatography. These individual substances are analysed in a mass spectrometer, and the data obtained used to determine their composition and concentration.
But the fundamental science of smell is still in its infancy. Some of the leading players in the field are showmen as much as scientists. Dr Dodd, for example, who set up the Institute of Olfactory Research at Warwick University in the 1970s, has developed a perfume as well as a fish attractant for anglers based on synthesised human female pheromones. He believes that the technology now available to the HPRG might also be used to reveal the secrets of human sexual attraction. “With this instrument I’d be disappointed if we weren’t able within six months for the first time to obtain individual pheromone profiles and then carry out pheromone profiling on a large scale, and for the first time ever begin to map out the individual differences in human body odour.”
Because so little is known about the human sense of smell, the focus in perfumery and other fields where odour is important has been on the empirical relation between a smell as smelled and the mood the smeller reports it induces. Knowledge of how odour is sensed and decoded by the nose and brain is not absolutely necessary in order to achieve desired results in these applications which is one reason why little research has been done in this area.
Without a fundamental understanding of how smell works, the first generation of “electronic noses” is aimed at mimicking animal noses. “Nature has solved the problem already,” says Dr Dodd. “A sniffer dog has sensitivity far exceeding any instrument we have for detecting smells.” Although typically trained to sniff out drugs and explosives, their ability to detect minute amounts of key substances is quite general. “We could train them on wine if we chose.”
“A biological system has an array of perhaps up to a thousand sensors,” Dr Dodd explains. “These are connected in complex ways to central processors which interrogate the sensors in ways that we do not understand.” In place of biological receptors, electronic noses use electrically conducting polymer substrates sensitive to the presence of certain groups of molecules, although exactly how these work is also unclear. Variations in the fabrication process and moisture in the sample greatly affect their performance. An electronic nose that can distinguish dry samples of different coffee varieties might still have trouble telling a steaming cup of Java from hot water. When it detects certain molecules, the polymer produces an electrical signal. The whole array of sensors will produce a mass of such signals of different intensities according to the composition of the gas mixture introduced. Statistical procedures may be used to analyse the mixture, or a neural network processor behind the sensors may be “trained” to distinguish particular odours from the background much like sniffer dogs or wine experts. One challenge is to balance the number of sensors and the computer power behind them. Following nature, it would seem that the more sensors the better—dogs have millions of them. But adding too many sensors can add to the “background noise” in the detected signal and slow down data processing.
For many applications, the ability to pick out target constituents from a mixture of odorants is more important than sensitivity to very low concentrations. While developing his electronic nose, Dr Dodd carried out development work with the brewer, Bass. The brewing process can go wrong in many ways, each producing its own cocktail of chemical contaminants. The requirement to distinguish between them directed the project away from increasing the sensitivity of the array towards developing the “parallel” computing processing that would enhance discrimination. Since those early days, both substrate sensitivity and the ability to process the signal arrays that they generate have improved. But electronic noses are still only good at detecting substances they have been “taught” to identify.
Nevertheless, progress in the field is keenly watched in industries such as food and tobacco where the aroma is a reliable indicator of its quality. A wide variety of applications are imagined. The Royal Veterinary College is developing technology to detect oestrus in dairy cattle. General Motors wants to identify the ingredients of “new car smell.” Unilever wants machines to replace the people who assess the effectiveness of under-arm deodorants.
Unlike either canine or electronic noses, the gas chromatographic mass spectrometry to be employed by the HPRG can, in principle, detect and identify any airborne substance. Although more sensitive than other devices, it is unfortunately an expensive and bulky item of equipment. “To be useful in the diagnosis of disease it’s got to be useful in 50,000 general practices,” says Dr Horrobin.
The sensitivity of mass spectrometry also offers hope for the perfume industry. Instead of brutally extracting the delicate raw materials from flowers to create scent, manufacturers might simply sample the air above a rose and synthetically recreate what we actually smell. But there are practical barriers. “The hype is that you can replicate whatever’s in the air,” says Dr Luca Turin of University College London, a perfumer and researcher into the molecular basis of smell. “But chemicals fall into two classes: ones you already have on your shelf, and ones that it takes years of work to make. So you can guess which ones get chosen. The reality is that it still takes a very good chemist and perfumer to figure out which are the important components.”
One advantage of an electronic analogue of a well-trained human “nose” is that it might be linked with other electronic systems. Although a recent application for European funds was turned down, the HPRG team hope ultimately that it might use the digital telephone network to provide home diagnosis of a range of illnesses. “We reckon we can have a sensitive test before people feel the need to go to a doctor,” says Dr Dodd.
There is already some evidence to indicate that conditions such as depression, which have similarities with schizophrenia, may also be diagnosed by testing skin or breath samples. Acetone is exhaled in the breath of some diabetics. It is known that bacteria in the colon produce other substances, so there may be a useful link to colon diseases. It is intuitively obvious that diseases from lung cancer to cirrhosis of the liver may affect the breath. There is also the possible biochemical connection between smelling abnormal and losing one’s sense of smell; anosmia. The loss of sense of smell is an early sign of schizophrenia as well as of Parkinson’s and Alzheimer’s diseases.
“Thirty years from now one could take a breath test rather than use intravenous blood sampling and pick up quite a range of diseases,” believes Dr Horrobin. “The aim really is to provide a much more sensitive and specific diagnosis for smell symptoms known in the 18th century.”
Capital Times (Madison, WI)
June 2, 1998
The sense of smell is often the forgotten sense—until a person loses the ability to smell (anosmia). Actually, most of us—two out of three—will suffer temporary anosmia, at least once in our lifetime.
Who among us has not had a head cold or sinus infection where we have complained: “I can’t smell a thing.”
Victims of head injuries are at high risk for entering a permanently odorless world that diminishes their experiences.
Certain medications, prescribed and over the counter, can also diminish the sense of smell. Brain tumors, influenza, allergies and normal aging are other factors that contribute to the loss of the olfactory sense in the millions of people in the United States who, literally, cannot smell anything.
Because odors are such powerful connectors to memory, it is particularly sad that the two seem to fade together. Anosmia is often found in Alzheimer’s disease patients. One wonders about the connection and significance of the parallel loss of memory and smell.
Are odors so strong that they can relieve pain? Some therapists in reputable medical centers think so and are using “aromatherapy” to relax patients and ease their discomfort.
Marketing experts have connected aromas and sales. They are convinced that the pleasant smells of a bakery, or other olfactory delights, influence how ready we are to part with our dough, so to speak.
Given the gravity of other physical conditions that people of all ages, but especially people in their later years, experience, isn’t the loss of smell just sort of a “ho-hum” nuisance?
Well, consider what that loss might mean to the gardener, to the wine or cheese testers who depend on their olfactory sense for a living.
What about every parent in the world who depends on the “sniff test” to determine the need for a diaper change? And who would diminish that same parent’s delight in smelling that same freshly bathed and powdered baby’s bottom?
Life is bland without a sense of smell.
Loss of a keen olfactory sense can also be extremely dangerous, even life threatening. Injuries related to a diminished smell include smoke inhalation. Normally, many older adults may not be able to detect faint traces of smoke, even when they are awake. When lost in the subconsciousness of sleep, even heavy smoke may go undetected. The same goes for gas leaks whose noxious smell goes undetected by those suffering from anosmia.
Consumption of spoiled food also presents a real and present danger for the “olfactory challenged,” especially if that person lives alone.
The sense of taste and the sense of smell are so closely related that when one is diminished, the other is equally affected. When food no longer tastes good, nutrition is compromised. Let the odor of coffee brewing permeate the kitchen and the appetite responds. The smell of lemon can do the same. A malodor will do just the opposite and destroy an appetite. The only thing worse than a truly noxious stink is no smell at all.
How would you know if you, or others you care about, are anosmic? They say “a rose is still a rose,” but if you, or a family member, are being accused of wearing too much rose water or other perfume, that might be a strong hint that the sense of smell is diminished. The overuse of spices may also indicate that the person is compensating for a loss of smell. Most refrigerators occasionally contain spoiled food, but frequent presence of odoriferous matter is a cause for concern.
Certainly your health care professional should be alerted when anosmia is suspected. This loss may indicate a serious physical problem. Beyond that, common sense must take over when olfactory sense is gone. Simple adjustments include installing smoke, gas and carbon monoxide detectors, learning to pay attention to the freshness dates on perishable foods and paying close attention to nutrition.
Even if one cannot smell the parsley, sage, rosemary or thyme, their use enhances the appearance of the food and provides a secondary way to enhance the appetite.
March 8, 2000
Imagine a World That You Couldn't Taste or Smell
By Ken Houston
‘SO, you have difficulty sleeping then?” said the friendly stranger I met on a long train journey. “Actually, considering the pressures of the job I sleep not too badly,” I corrected. “I am talking about anosmia, not insomnia.”
I explained what anosmia (the word comes from osme, Greek for nose) actually was—the total loss of sense of smell and the ability to taste the flavour in food. “Mmm a must be difficult,” he muttered; but I could tell he did not really understand.
Still, before being hit by the condition almost ten years ago, I would have shared his ignorance. Periodically, panelists on Any Questions? are asked: “If you had to choose, would you rather be blind or deaf?” To my knowledge, nobody has ever been asked to choose between blindness, deafness or anosmia.
This is probably because anosmics outwardly appear “normal.” Unlike blind or deaf people they can walk unaided, have a conversation, drive a car, read a book or listen to music.
What they cannot do is taste the flavour of any food or drink: not the hottest curry or the purest malt whisky. Anosmia sometimes occurs as a result of a head or face injury or, as in my case, for no apparent reason at all; I woke up one morning being able to smell and taste as normal and by the time I went to bed that night it had gone; it was as unremarkable as that.
Initially, my GP appeared confident that this was some temporary aberration, but decongestant tablets and a strong nasal spray had no effect. My personal life was being turned upside down. Only when flavour disappears does one begin to really appreciate the contribution food makes to the quality of life.
Lunch, whether a cheese sandwich or a four-course meal, gives a psychological lift to the working day, but not for the anosmia sufferer, who eats to fill the stomach and nothing more; lunch is not a “break” in the accepted sense. Likewise, one of the most simple but important pleasures in life—the smell of cooking on returning home—is totally lost on you.
But if the working week was difficult, weekends were a nightmare.
All the pleasure of a Saturday night meal or Sunday lunch with family or friends had completely evaporated, but I still had to go through the motions if I did not wish to become a social recluse. When eating out I would tell anyone who would listen about my condition, but I stopped when it became clear they were feeling guilty about tasting their food when I could not. So if a waiter appeared with four sizzling steaks and someone commented: “Doesn’t that smell delicious?” I would fib back: “Mmm ... doesn’t it just.”
One unwelcome consequence of eating out was that my intake of alcohol increased sharply. Beer and wine were just as tasteless as food, but at least I still received the “buzz” that alcohol usually provides.
Ironically, however, my new condition led to an improvement in one sense. Because “forbidden” foods gave me no pleasure, I began to eat poultry whereas before I would have had red meat; boiled potatoes were substituted for chips, fruit instead of puddings, and as a result my excess weight simply dropped off.
Despite my misery and self-pity, in one sense I had probably never been healthier in my life.
Eventually, it was recommended that I have a nose operation to try to correct the problem, but it failed to produce the desired effect. At a post-operative meeting with the surgeon some two weeks later he said, ominously: “You might have to learn to live with this.”
Actually, my smell (which is the basic problem, for from smell comes taste) did return three months later—seven months after the condition first occurred. After more than half a year of nothingness, the ability to smell roasting coffee or taste a slice of toast dripping with butter produced feelings of indescribable joy.
Sadly, it was a short-lived reprieve.
Within another two months my sense of smell had disappeared again, and that has been the pattern ever since: long periods of little or no sense of smell with shorter periods of remission (as is happening now).
There is no alternative but to heed the surgeon’s advice to “learn to live with it” (although some sufferers cannot—the suicide rate for anosmics is higher than the population at large). But it is a condition that is difficult to accept. I have tried hypnotherapy and acupuncture, among other would-be remedies, and found various sites on the web where anosmics from all over the world share their problem. Although each experience varies, most have a common thread—decongestant tablets, nasal sprays and operations which all proved to be useless.
Indeed, I was beginning to think that on this issue the medical profession was still in the dark ages until I came across the work of Gerry McGarry, a surgeon in the ENT department at the Royal Infirmary in Glasgow. Although an experienced practitioner in ear, nose and throat, McGarry now specialises in rhinology (study of the nose). His move has led to encouraging advances—not only affecting smell and taste.
“Up and down the UK we are seeing more surgeons specialising to keep up with the pace of change,” McGarry says. “Here at Glasgow we have pioneered some new surgical techniques, but I don’t want the impression given that we have suddenly discovered cures for various conditions. What it means is that we are up to speed.” Turning to his role in olfaction, he says: “Smell develops as we grow and declines as we age; it is commonly thought that babies and very young children still do not have a proper sense of smell.”
When adults lose their sense of smell for no apparent reason it is usually for one of two reasons: growths in the interior of the nose, such as polyps, or damage to the nerves (often as the result of a virus) which connect the nose to the brain—and deliver to the individual the smell and flavour of food.
McGarry says the former can often be cured, or at least relieved, by surgery. However, he says, the second problem usually proves to be an intractable one. The link between nose and brain—the sensorineural nerve—is situated right at the roof of the nose “in an awkward and inaccessible position”, says McGarry.
To explain further he uses the analogy of the record player: “It is a bit like the pick-up not working because the wires on the stylus are broken and at the moment these are something that we cannot fix.”
But before considering surgery, McGarry will first ascertain the extent of the problem, partly by using a technique developed at the University of Pennsylvania in the US and involving a scratch-card-type smell test of various flavours ranging from chocolate to engine oil. This will determine whether patients are totally anosmic or hyposmic, which is the term used for partial loss of the sense of smell, and at what level this loss is. The test is also used on the small minority of patients who feign a loss of smell—for example, fraudsters trying to make bogus compensation claims.
McGarry actually had good news for me: because my sense of smell does return from time to time, my own problem is unlikely to be down to damaged nerves. Despite my long periods with no sense of smell or taste at all, he told me: “You suffer from hyposmia rather than anosmia.”
Anosmic, hyposmic, who cares? Just the renewed hope that, one day, my condition might yet be reversed was something that smelled particularly sweet to me.
The New York Times
May 16, 2000
Emotional Malady is Linked to Smell
By Erica Goode
The sense of smell, as Marcel Proust and his madeleine made clear, is intimately tied to feeling and memory.
So it is perhaps not surprising that in schizophrenia, an illness that plays havoc with the emotional capacities of those who suffer from it, the sense of smell is impaired.
People with schizophrenia often display what psychiatrists describe as a “blunting” of emotional response that makes it difficult for them to relate to others. But they also, researchers have found, show deficits in their ability to detect, identify and remember odors.
Now a new study, appearing in this month’s American Journal of Psychiatry, suggests that these abnormalities in the sense of smell have their root in abnormal brain structure.
Using magnetic resonance imaging, Dr. Bruce Turetsky, an associate professor of psychiatry at the University of Pennsylvania, and his colleagues examined the olfactory bulbs—blueberry-sized organs that act as relay stations between the nose and brain—in 26 schizophrenic patients and 22 comparison subjects. The bulbs of patients with schizophrenia, the researchers found, were on average 23 percent smaller in volume than those of control subjects.
The discrepancy in size, said Dr. Turetsky, was large enough that it was clearly visible on the M.R.I. scans. And the difference between the groups persisted even after cigarette smoking, the use of anti-psychotic medications, age and other factors that might influence the size of the bulbs were taken into account.
The study, said Dr. Robert Bilder, associate director for human research at the Center for Advanced Brain Imaging of the Nathan Kline Institute for Psychiatric Research in Orangeburg, N.Y., is, he believes, the first to reveal, in schizophrenia, a structural abnormality in more primitive brain areas, which are also involved in emotional processing.
“For the last 10 or 20 years,” Dr. Bilder said, schizophrenia researchers have paid “an enormous amount of attention to the higher parts of the brain and the associated higher cognitive functions. This kind of a study is important in moving the focus to lower brain systems, that are crucial to the regulation of emotion and visceral functions.”
Further investigation of the relationship between olfaction and schizophrenia, Dr. Turetsky said, may also help shed light on the emotional disturbances that are characteristic of the illness.
“Smell is so tightly linked to emotional processing,” Dr. Turetsky said. “It’s essentially impossible to present an olfactory stimulus that doesn’t have an emotional valence to it.”
The olfactory system offers scientists a unique window on both normal and abnormal brain functioning, in part because it is so clearly laid out, with sensory impulses traveling from receptors in the nose to the olfactory bulbs, where they are decoded, and then to olfactory centers in higher brain regions. And the changes in olfaction observed in schizophrenia, researchers believe, may also contain clues to how the disease develops. Many scientists suspect that schizophrenia is a neurodevelopmental disorder, a result of hereditary predisposition and some environmental insult, perhaps occurring during the early months of fetal growth.
Whether the smaller size of the olfactory bulbs in schizophrenia reflects abnormalities occurring early in development or stems from a degenerative process later in life is still unknown, Dr. Turetsky said. But, he pointed out, olfactory neurons, unlike those in other areas of the brain, die and are replaced throughout life, displaying a plasticity that makes the olfactory system relatively resistant to degenerative disease.
A loss of smell or abnormalities in odor identification or detection is also seen in some degenerative diseases, like Alzheimer’s. The next task facing the researchers, said Dr. John Q. Trojanowski, a professor of pathology and laboratory medicine at Penn, is to show that the smaller volume of the olfactory bulbs is specific to schizophrenia and is not found in other illnesses, like manic depression, alcoholism or dementia.
Although scientists have been studying the brains of patients with schizophrenia for a century or more, no one appears to have ever noticed a difference in the size of the olfactory bulbs.
One reason, Dr. Trojanowski said, maybe that early researchers saw no particular reason to pay attention.
“If you look at how the bulbs sit in the skull when you take out the brain, it’s easy to leave them behind,” Dr. Trojanowski said.
Daily Mail (London)
July 11, 2000
The attack that stole my sense of smell...
By Ivan Waterman
ACTOR Simon Ward, 57, shot to fame in the 1972 film Young Winston. But in 1987 he suffered a major setback after a brutal attack at a London Underground station left him with a fractured skull. Then, four years ago, he developed the chronic blood disorder polycythaemia, for which he still takes medication.
…As a result of the surgery on my skull, I have also lost my sense of smell. For about a year I could smell nothing, then it started to come back, but it’s still not what it was.
Smell is something that most people take for granted and it was some time before I realised how important it is and what I had lost. What I missed most was not being able to appreciate our garden.
Now, I can smell flowers again but it’s difficult to determine exactly what I still might be missing. …
Derby Evening Telegraph
November 4, 2000
Forced to Live in a Senseless World
By Simon Burch
LIFE for Heather Rushton is like living with the symptoms of flu every day of the week.
When the 34-year-old eats, she can’t taste her food. When she sprays on her favourite perfume, Chanel Number Five, she can’t smell it.
This has been how it is for the last six years of her life.
Badly injured in a road accident in 1994, Heather no longer has her senses of smell and taste. Loss of sense of smell is called anosmia, the loss of taste is called ageusia and the two senses are recognised as less important than our sight, hearing and touch.
Her losses are not debilitating or life-threatening in this day and age and Heather has been deprived of the senses for so long that she has come to accept it as normal.
“You just take it for granted,” she says, “I’ve lived with it that long that I’m just used to it.”
Heather, who works for Eurest, in London Road, first realised her senses had gone when she ate a meal prepared by her mum, Veronica (known to everyone as Von), after returning home from hospital a few weeks after her accident.
“She was eating it and said to me ‘I can’t taste this at all,’” Von says.
“From then on we sort of realised what had happened and they confirmed it at the hospital.”
Heather was taken to the Derbyshire Royal Infirmary by air ambulance after her car was involved in a collision with a parcel delivery van in Staffordshire, while she was driving between her jobs as a barmaid one lunch time.
“I spent a month in intensive care,” she says, “and it’s a whole month I can’t remember anything about.”
“It was touch and go at one stage,” confirms Von.
After regaining consciousness, Heather was transferred to King’s Lodge at Derby City Hospital and went home soon after.
After Von reported Heather’s comments at the dinner table, doctors told her that areas of Heather’s brain, which had swelled up to twice its normal size after the crash, had been crushed. The areas affected control taste and smell.
“They said it was only the size of a fingernail and apparently what had happened was that Heather’s brain grew so much that it knocked out two of her senses.”
Heather is now unable to savour those things the rest of us take for granted.
She has been told she could have an operation which might restore her senses but she doesn’t want to go under the knife again.
“It’s not worth it,” she says.
She has accepted that she’ll never again experience the smell of sizzling bacon, the scent of fresh bread or catch the mouth-watering odour of fish and chips.
“The one thing I really miss is the smell of a newly-cleaned room.
“When I’ve cleaned a room I can see that it looks nice, but I just can’t smell it and it would make such a difference,” she adds.
Heather has also installed an atomiser pumping in her home, which pumps a fragrance of potpourri around her living room—not that she knows much about it.
“I keep putting the drops in but I can’t smell it. I always ask ‘what does it smell like’ because I could put the whole bottle in and I still wouldn’t smell it.”
She also confesses to wanting to get into a bed and smelling the clean, crisp sheets, a pleasure no longer available to her.
Heather and her boyfriend, Mick Howitt (34), eat curry once a week.
Heather never used to eat them until she lost her sense of taste, while Mick is a self-confessed curry fan.
She’d like to taste a curry now.
“I never used to like them but I’d love to try one and see what it tastes like. To me, all food’s the same.
“All I can tell you about now is the textures. Eggs are slimy, bacon’s chewy but they taste the same to me.”
The up-side of losing a sense of taste is that Heather can eat anything she likes, including fresh lemons and the hottest of hot curries.
“We’ve had ones where I’ve been sweating and Heather’s just eaten it straight down,” Mick says.
“I never used to eat any veg at all because I didn’t like it,” says Heather, “but now it doesn’t matter because it doesn’t taste of anything.”
She can also drink what she wants, although she likes lager with an unnecessary dash of lime (“It’s what she’s always had,” says Mick) and can even mix drinks together without worries of what the concoction tastes like. Heather would even be none the wiser if someone spiked her drink, but she would still get “a kick” from it. But just because she can’t taste tastes or smell smells, she’s not unaware of the effect this has on everyone else.
She makes curries to Mick’s own preference and when the couple go out she always makes sure she’s wearing her favourite perfume, Chanel Number Five. Why?
“Because other people can still smell it and when you know you smell nice you feel better. You don’t want to be stinking of sweat, do you? I never wear too much, though. I’ve never gone over the top with it because I know how much I used to put on when I could smell it and put the same amount on. The only difference is that I have to now ask Mick if I smell all right before we leave.”
Mick, an engineer, is the opposite. He likes to wear aftershave but has no one favourite. He likes to wear different ones.
He knows Heather can’t smell his after-shaves but enjoys the smell himself. The only problem for him, though, is choosing which after-shave to buy.
“It’s hard work because I’ve got no-one to tell me which one is the nicest.
It’s good to have another opinion but Heather can’t tell me so I have to make my own decision.”
This apart, Mick has things pretty good.
Because Heather can’t taste her food, everything she buys and cooks is based on what he likes.
He smokes, she doesn’t, but he’s allowed to smoke in the house now because Heather can’t detect the smoky smell.
Heather says: “I always used to hate smoking and I still do. It’s disgusting and degrading but I can’t smell it in the house so it doesn’t bother me so much.”
Mick’s laughing but he is worried because, if there was a fire or a gas leak, Heather would be in danger because she’d be unaware of the early warning smells.
“I’m on nights at the moment and so if Heather was in during the day she could be in danger. Once she left a chip pan on but wasn’t aware of it because she couldn’t smell the burning. Whenever I come home I always make sure I sniff the air first when I open the door before I turn the light on, just in case.”
Heather, Von and Mick believe Heather got away relatively lightly after her ordeal six years ago— “although my memory’s useless now too,” —and she’s willing to sacrifice her smell and taste senses to make sure she doesn’t have to go back into hospital.
It does annoy her though when other people don’t realise her predicament.
“In the beginning my mum would say ‘what’s that smell?’ and I’d get really frustrated about it and tell her to stop.”
“It’s just one of those things, you just forget about it,” says Von defensively.
“That many people keep saying things like that without realising it that it does get annoying,” Heather continues. “But as far as I’m concerned it’s something I’ve taken on board and I just get on with it.”
December 24, 2000
Andrea’s Christmas Really is One that She’ll Savour
By Kath Gourlay
Tomorrow will beat all Andrea Askew’s other Christmas Days by a nose because for just 24 hours she will be able to do what the rest of us take for granted—smell and taste her Christmas dinner.
Three years ago the mother-of-two lost both senses after a mystery virus damaged the olfactory receptors in her nose.
Despite repeated medical investigations no permanent cure has been found for her condition, which has blighted her life since.
She can no longer tell when her cooking is burning, or even if she has body odour. But this weekend she has become a medical guinea pig for an experiment which may benefit fellow sufferers from anosmia—complete loss of smell. On Friday she began taking a powerful dose of high potency steroid drugs to try to reduce swelling in the damaged nerve endings in her nose. The drugs should start to take effect today and last over Christmas Day. She said: “If I’m lucky, I could get Boxing Day as well, which will save me pigging out in one day on all the treats such as continental chocolate and rich Christmas pudding.
“It’s not just the food—it’s having a shower and smelling the shampoo. It’s touching the branches on the tree and smelling the pine resin. It’s just one glorious day when I can feel normal.”
Her family, husband Adrian and daughters Kate and Erin are fully behind her decision, though younger daughter Erin is fiendishly interested in the possible side effects—she has joked about her mother growing a beard for Christmas.
But Andrea, 42, is like an excited child about the day. “I know my sense of smell can vanish literally in minutes again so I’m going to take advantage of every opportunity to use it. I’ll be useless at food preparation—I won’t be able to stop sniffing long enough to cook anything,” she said.
The special needs assistant at Kirkwall Grammar School, on Orkney, remembers her strange virus. “It was horrible,” she said. “Suddenly everything began to smell and taste like burnt matches. Then there were other queer tastes and smells and then everything just went.”
According to consultant surgeon Kim Ah-See, from the Ear Nose and Throat Department at Aberdeen Royal Infirmary, such symptoms are typical when the olfactory nerve is damaged.
“The nerve is like a hairbrush,” he said. “It runs from the brain down to the roof of the nose where it breaks off into masses of tiny fibre receptors between the eyes. They are incredibly sensitive and if they are damaged they misfire, and send altered messages. If the damage is serious they lose their ability to receive and transmit messages.”
If the treatment is successful, it may be added to the long list of possible treatments of the condition.
Yesterday Andrea said: “You name it, I’ve tried it. Nasal sprays, allergy tests and the most horrendous operation to open up the nasal passages. I’ve been waiting for a year for a place in the Homeopathy Hospital in Glasgow, so I’ll give that a try, but it’s so frustrating, it affects so many things in your life.”
She has become obsessive about personal cleanliness, always washing and showering because she doesn’t know whether or not she smells.
The condition has also played some nasty tricks. She explained: “On a couple of occasions I’ve suddenly smelt things for a few minutes. That was more depressing than if it had never happened at all.”
So what if tomorrow’s experiment doesn’t work?
“They’ve tested my reaction to the drug and its one of these really powerful things that zaps allergens in your body. I could smell things, so I’m really optimistic.”
Mr Ah-See describes the drug as a “desperate last resort” and not to be used lightly. “These types of drugs are for people with severe immunodeficiency conditions, and while a short blast of such potent steroids may have some effect, it is very much a one-off treatment.”
But Andrea is ready to take the risk to enjoy at least one Christmas like everyone else.