Food sensitivity


Nothing to Sneeze At

Someone told me the nuts on a danish were almonds," remembers Kathy Sheehan of suburban Washington, D.C. "I ate them and my throat got very scratchy right away. I had stomach cramps, diarrhea, and then I was gasping for breath. I passed out."

As it turned out, the "almonds" were peanuts, and Sheehan almost died.

Kathy Sheehan is one of the tens of millions of Americans who suffer from food sensitivities. For a small number of them, avoiding foods like peanuts or shellfish is a matter of life and death. For most others, it's enduring skin rashes and sniffles, headaches and wheezing, gas and abdominal cramps.

And then there are the folks who blame their food for problems that have nothing to do with what they eat.

Knowing if you have a food sensitivity, what is causing it, and how to deal with it can make all the difference between enjoying your food and fearing it.

Most adults don't have to worry about food allergies.

"It's mostly a children's disease," says S. Allan Bock of the National Jewish Center for Immunology and Respiratory Medicine in Denver.

"True food allergies affect no more than about seven percent of children and two percent of adults." And relatively few foods are responsible.

In a study of more than 300 children begun in 1973, Bock and fellow researcher Charles May showed that 95 percent of their allergies were due to just seven foods: milk, eggs, wheat, soybeans, seafood, nuts, and peanuts (which are legumes).[1]

The only treatment for a food allergy is to avoid the food, at least for a while. "Most children outgrow their allergies within a few years," says allergy expert Dean Metcalfe of the National Institutes of Health. And, in about a third of the cases, he adds, adults' allergies also disappear if they stay away from the offending food for a year or two.

Most reactions to food are caused not by allergies, but by intolerances. If you're plagued with gas when you drink milk, or get a headache when you have some red wine, or break out in hives after eating strawberries, then you may have an intolerance.

Unlike allergies (see photo, p. 13), intolerances have nothing to do with the antibodies our immune systems produce. For example, an intolerance can occur if you are especially sensitive to drug-like substances that are found naturally in some foods.

Here are some food intolerances:

Lactose. It's the most common one. It affects some of the millions of Americans whose bodies don't produce enough of the enzyme lactase to digest all the lactose (milk sugar) they consume. Large amounts of undigested lactose overwhelm the large intestine, producing gas or diarrhea. It's a particular problem for Blacks, Asians, and people of Mediterranean heritage.
Sulfites. They're used as preservatives in some dried fruits, wines, and dried potato products like mashed potato flakes.
About five percent of asthmatics--more than a million people--have difficulty breathing after eating a food that contains sulfites.

If you're sensitive, avoid foods that contain sulfur dioxide, sodium sulfite, sodium or potassium bisulfite, or sodium or potassium metabisulfite.

• Monosodium Glutamate (MSG). It's been fingered as the culprit responsible for "Chinese Restaurant Syndrome"--the burning sensation, facial pressure, and chest pain some people feel after eating Chinese food, which can be high in MSG.

Many people report symptoms like headaches, diarrhea, and asthma when they eat small doses of MSG.[2] But few good studies have tested small doses in people who say they are sensitive.

If you think you react, avoid foods that list MSG or hydrolyzed vegetable protein (HVP) on their labels. And ask your Chinese restaurant to prepare your food without MSG. Some will.

Red Wine. Some people get head aches after drinking red wine. It's probably not the alcohol, but the phenolic flavonoid compounds from grape skins. They're found in higher quantities in red wine than in white.[3]
Chocolate. Many of the ingredients used in making chocolate candy could be responsible for the headaches that some people report. They include milk, nuts, soybeans, or corn syrup. And some of us may be exquisitely sensitive to chocolate's very small amount of phenylethylamine.[4]
Food Additives. Do some children react to flavorings, colorings, and other food additives? In 1989, Bonnie J. Kaplan and her colleagues at the Alberta Children's Hospital in Canada tried to find out.
They provided the families of 24 hyperactive boys with specially prepared meals. For three weeks, the food was similar to what the families normally ate. For the next four weeks the food was prepared without artificial food dyes or flavors, preservatives, MSG, chocolate, and caffeine. It also contained lower amounts of sugar and, for some families, no dairy products. The researchers took elaborate precautions to ensure that the families couldn't tell the difference between the foods, or even that there were two diets being tested.

The results? During the four weeks on the additive-free meals, the behavior of ten boys showed "marked improvement." Four others showed modest improvement. The remaining ten boys' behavior didn't change.[5]

• Sugar. Many parents and teachers swear that children become "hyper" and unmanageable after eating sugary foods. But several careful studies have found that only a small number of kids may be sensitive to sucrose, or table sugar. And, sugar is as likely to calm children down as it is to stir them up.

One recent study reported that sugar had no effect on 39 different measures of behavior or school work in 23 children whose parents said they were sensitive to it.[6]

Of course, it's possible that some kids don't react to sugar, but to the colors and flavors that-are often found in sugary foods. Also, most studies tested table sugar, but more than half of all the refined sugar we consume comes from corn, which might cause reactions.

Assuming your reactions aren't severe, here's what you can do;

• Treat Yourself. If you suspect that a food is making you sick, eat less of it. If you have an intolerance, you may find an amount that you can stand.

For instance, many cases of lactose intolerance "disappear"--along with the need for special lactose-free products or lactase drops--when people cut down on the amount of lactose they consume at one time. That can mean drinking smaller amounts of milk or eating dairy products like yogurt and hard cheeses, which are naturally lower in lactose.

If that doesn't work, eliminate the food from your diet. If your symptoms disappear, and then reappear when you try the food again, stay away from it if you can.

After a year or so, test the food again to see if you still react. "But don't do something stupid," warns allergist S. Allan Bock, "and eat a food you have reason to believe will cause a severe reaction just to find out if you're still allergic."

• See a Physician or Allergist. Sometimes it's not easy to pin down which foods you react to. Or maybe you think that you're sensitive to so many foods that you face complicated changes to your diet. If so, see a physician or allergist.

Often, all it takes is a look at what you eat and when you react to see what's what.

If that doesn't work, the doctor may give you one of several laboratory tests or put you on an elimination diet. You'll start out eating foods to which almost no one reacts (typically rice, vegetables, non-citrus fruits, and fresh meats and poultry). Then you'll add, one by one, the foods that most often cause problems, until you react.

But there's only one way to prove whether you react to a food--a challenge.

It's the "gold standard."

"It's really the only way in many cases to determine if someone suffers from a food sensitivity," says allergist John Anderson of Detroit's Henry Ford Hospital.

In a food challenge, a physician will feed you extracts of the suspect food in capsules or drinks on some occasions, and at other times will give you a placebo (look-alike capsules or drinks).

Generally, neither you nor the physician will know when you're getting what (a nurse keeps track).[7]

If you consistently react to the food but not to the placebo, then you're sensitive to it. Period.

This technique can be a real eye-opener. "Nine out of ten people who come to me convinced that they are allergic to a food don't react if they are given that food without their knowing it," says allergist S. Allan Bock.

Of course, the people could be sensitive to something else--maybe an ingredient or additive--that isn't always in the food.

Not all allergists do challenges. It's time-consuming, extracts of many foods aren't easy to find, and physicians worry about patients going into anaphylactic shock. A challenge can also be expensive, and most health insurance companies won't pay for them.

But if you really want to know if you react to a food, there's no better way to find out.

Journal of Allergy and Clinical Immunology 78: 165, 1986.
Adverse Drug Reactions and Toxicological Reviews 11: 19, 1992.
Lancet 1: 558, 1988.
Immunology and Allergy Clinics of North America 11: 831, 1991.
Pediatrics 83: 7, 1989.
New England Journal of Medicine 330: 301, 1994.
Journal of Allergy and Clinical Immunology 82: 986, 1988.
For reliable information on food allergies, call the Food Allergy Network at (800) 929-4040 or the Allergy and Asthma Network at (800) 878-4403.
To join a support group, call the Asthma and Allergy Foundation of America at (800) 727-8462.
For the names of board-certified allergists, call the Allergy Information Referral Line at (800) 822-2762.
For the names of clinical ecologists, call the American Academy of Environmental Medicine at (303) 622-9755.
PHOTO (COLOR): Allergic reactions occur when intruder-fighting antibodies snare an offending food. This causes the mast cells that line the intestines, skin, and respiratory tract to give off irritating substances. The mast cell on the right is releasing histamine.



While most food allergies are not life-threatening, some 1,000 Americans go into anaphylactic shock every year after eating a food they're extremely allergic to. A half dozen or so may die.

Even the tiniest amount of the food can be dangerous.

Several years ago, a man who was allergic to peanuts was assured by the waiter in a Vietnamese restaurant that the dish he ordered was peanut-free. A few minutes after serving the food, the waiter told the man that it did, in fact, contain slivered peanuts. The man pushed the dinner aside. Despite having taken only one bite and having gone to the restroom to administer himself emergency adrenaline as a precaution, he was dead within two hours.[1]

The foods that most frequently trigger anaphylactic shock are peanuts, fish, nuts, shellfish, milk, eggs, and soybeans. If you think you are extremely sensitive to any food, see a doctor.

1 Journal of the American Medical Association 260: 1450, 1988.

Are our immune systems being suppressed by chemicals in our food and in the environment?

That's what clinical ecologists say. And this, they claim, can lead to asthma, rashes, and diarrhea, as well as depression, fatigue, headaches, and mental confusion.

"The total load an individual faces can include everything from exposure to chemicals at work to cat dander, ragweed, food allergies, and even visits from relatives," says Kenneth Gerdes, president of the American Academy of Environmental Medicine, the professional society of clinical ecologists.

"And of these," he adds, "one of the most important in almost every person is a sensitivity to something in food."

Most clinical ecologists are physicians who combine conventional techniques like elimination diets with unconventional methods like:

• Cytotoxic Testing. Blood is mixed with suspect foods and then inspected for telltale changes in white blood cells. But the results fluctuate so much that the test is worthless for diagnosing allergies.[1]

"Very few of our members use this test any more," says Gerdes. "We used to joke that the number of allergies diagnosed depended on how the technician was feeling in the morning."

Provocation-Neutralization. Patients are exposed to dilute solutions of suspect foods. This first triggers, then "eliminates," allergic symptoms. But in one good study, water produced the same results.[2] Clinical ecologists say that the study wasn't conducted properly.
Sublingual Drops. Dilute solutions of offending foods are placed under the tongue. That "protects" patients from allergic reactions to the foods. Under controlled conditions, however, the drops are no more effective than a placebo.[3]
"We know from our experiences with patients that provocation-neutralization and sublingual drops work," says Gerdes. But, he admits, "we don't have the clear scientific evidence to prove it, because we're healers, not researchers, and we don't have the financing to do big controlled trials."

Annals of Allergy 45: 150, 1980.
New England Journal of Medicine 323: 429, 1990.
Medical Hypotheses 25: 7, 1988.

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