Many Americans experience unpleasant side effects from digesting certain foods–an upset stomach, bloating, gas or mild diarrhea. These reactions do not constitute an allergy but rather a food sensitivity or sometimes simply an aversion to certain foods.
A true food allergy, which is much less common, is an abnormal response triggered by the immune system. Symptoms may include an itching or tingling in the mouth, swelling of the tongue and throat, hives, difficulty breathing, wheezing, vomiting, abdominal cramps, a drop in blood pressure and even loss of consciousness or death. Known as an anaphylactic reaction, this is a medical emergency which can occur within minutes or as long as two hours after the person has eaten the offending food.
Don’t Self Diagnose
These are not symptoms to take lightly. Allergic reactions send about 300,000 Americans to the emergency room each year and are implicated in about 150 deaths. There are other reasons for any of these symptoms, of course, and a food allergy is not something you can or should diagnose yourself. See a doctor for an examination and testing.
Although about 200 substances in food can potentially cause a reaction, 90 percent of allergies are to what is known as the Big Eight: peanuts, tree nuts, cow’s milk, eggs, wheat, soybeans, shellfish and fish.
The process starts when a predisposed person consumes food containing the allergen. The person’s immune system responds by producing immunoglobulin E (IgE), an antibody that then attacks the offending substance on later occasions when the food is eaten.
Allergies typically develop early in life, and many children outgrow them by age 10 or so. Some food allergies linger into adulthood, however.
Eating the food, even in miniscule amounts, can bring on a reaction, often severe. In fact, some persons have experienced attacks brought on by passing a restaurant cooking shellfish or kissing someone who has eaten a peanut butter sandwich.
For the person with the food allergy, the world around is fraught with danger. Taking the nuts off the top of a piece of carrot cake is no solution; the cake below has been contaminated. If a chocolate bar is made with machinery that previously processed nuts, it may as well be a handful of peanuts.
A new law went into effect at the beginning of 2006 making life somewhat easier for food allergy patients, their family and friends. Any product labeled after January 1, 2006 must state if the food includes any of the Big Eight allergens in even trace amounts. The warning must be in “plain language”–the term “milk,” for example, as opposed to “casein” and “whey,” which many do not realize are milk products.
What the law does, more than anything else, is to put the idea of food allergies more prominently in front of the public. Since there is presently no cure, the only treatment is to avoid the offending food–which can be done only if food labels are complete and accurate in their descriptions.
Allergic reactions are most common when the person is eating outside the home. The patient is advised to avoid buffets and salad bars, where cross contamination is possible.
If you’re cooking for someone with a food allergy, pay attention to all the ingredients you use. Worcestershire sauce, for example, contains anchovies–not for the person with an allergy to fish. Make sure your pans, knives and cutting surfaces offer no chance for cross contamination.
The ultimate solution is to prevent the development of food allergies, and that would be simpler if scientists could explain the recent increase in the number of Americans plagued by food allergies.
Food allergies are rare in third world countries and increasingly prevalent in the developed world. One reason may be greater awareness, but some believe that cleanliness may also be a factor. According to this theory, immune systems that are consistently challenged are better able to function than those dealing daily with a sterile, antibacterial environment. For perhaps the same reason, children who attend day care centers are less likely to develop allergies because they’re constantly exposed to bacteria.
Allergies tend to run in families, and current advice for pregnant women who have a family history of allergies is to avoid eating allergen-containing foods during the last trimester and while breast feeding the baby.
Breast feeding is recommended as a way to reduce the risk of food allergies, and parents are advised not to introduce solid foods too early–particularly nuts, seeds, wheat, cow’s milk, fish, shellfish or eggs.
Vitamin supplements, given during the first six months, have also been implicated in the development of food allergies. One study published in Pediatrics [July, 2004] found an association between supplements and asthma in black infants and between supplements and food allergies in all children–particularly formula-fed babies. A causal relationship was not established.
There is clearly much to learn about food allergies, but an important first step is recognizing the danger. Food allergies are real, and 11 million Americans have one. On the other hand, six or seven times that number believe they have a food allergy, sometimes putting themselves at risk of dietary deficiencies by eliminating whole classes of foods.
If you’re concerned about your reaction to certain foods, see a doctor. If you know someone who has a diagnosed food allergy, do your best to offer support and protection.
Tana N Kaefer, PharmD
