|
Food Allergies
By the end of this lesson you will:
What are food allergies? Do you start itching whenever you eat peanuts? Does seafood cause your stomach to churn? Symptoms like these cause millions of Americans to suspect they have a food allergy.
But true food allergies affect a relatively small percentage of people: Experts
estimate that only 2 percent of adults, and from 2 to 8 percent of children, are
truly allergic to certain foods. Food allergy is different from food
intolerance, and the term is sometimes used in a vague way, making it difficult
for people to understand the difference. ALLERGY AND INTOLERANCE--DIFFERENT PROBLEMSFirst let's start by getting the facts straight about food allergies. The difference between an allergy and an intolerance is how the body handles the offending food. In a true food allergy, the body's immune system recognizes a reaction-provoking substance, or allergen, in the food--usually a protein--as foreign and produces antibodies to halt the "invasion." As the battle rages, symptoms appear throughout the body. The most common sites are the mouth, digestive tract, skin, and the airways. People with allergies must avoid the offending foods altogether. Cow's milk, eggs, wheat, and soy are the most common sources of food allergies in children. Allergists believe that infant allergies are the result of immunologic immaturity and, to some extent, intestinal immaturity. Children sometimes outgrow the allergies they had as infants, but an early peanut allergy may be lifelong. Adults are usually most affected by tree nuts, fish, shellfish, and peanuts. Food intolerance is a much more common problem than allergy. Here, the problem is not with the body's immune system, but, rather, with its metabolism. The body cannot adequately digest a portion of the offending food, usually because of some chemical deficiency. For example, persons who have difficulty digesting milk (lactose intolerance) often are deficient in the intestinal enzyme lactase, which is needed to digest milk sugar (lactose). The deficiency can cause cramps and diarrhea if milk is consumed. It is quite different from the true allergic reaction some have to the proteins in milk. Unlike allergies, intolerances generally intensify with age. For people with true food allergies, the simple pleasure of eating can turn into an uncomfortable--and sometimes even dangerous--situation. For some, food allergies cause only hives or an upset stomach; for others, one bite of the wrong food can lead to serious illness or even death. Food intolerance may produce symptoms similar to food allergies, such as abdominal cramping. But while people with true food allergies must avoid offending foods altogether, people with food intolerance can often eat some of the offending food without suffering symptoms. The amount that may be eaten before symptoms appear is usually very small and varies with each individual.
Who is likely to develop a food allergy?
Symptoms? What are the symptoms of a food allergy? It is possible that there are different reactions for the same allergen in different people. Symptoms may appear within seconds or up to several hours after eating the food that triggers the reactions. In exceptionally sensitive people, just the touch or smell of the food can provoke a reaction!
Emotions associated with food experiences, and not the food itself, can even cause a reaction. Just the appearance, smell, or taste of food might trigger an emotional reaction, which results in symptoms that mimic a food allergy or food intolerance. Or someone might get these symptoms by believing the food is harmful. Even if you suspect that emotions are at the root of an adverse reaction to food, check with your physician. Symptoms may stem from a more serious physical condition. To date, there's no scientific link between food allergies and arthritis, migraine headaches, behavioral problems, ear infections, and urinary tract infections, although research in these areas is underway.
Activity 2:
Can food allergies be dangerous? Usually reactions to food allergies are more uncomfortable than dangerous. The greatest danger in food allergy comes from anaphylaxis, a violent allergic reaction involving a number of parts of the body simultaneously. Like less serious allergic reactions, anaphylaxis usually occurs after a person is exposed to an allergen to which he or she was sensitized by previous exposure (that is, it does not usually occur the first time a person eats a particular food). Although any food can trigger anaphylaxis (also known as anaphylactic shock), peanuts, tree nuts, shellfish, milk, eggs, and fish are the most common culprits. Anaphylaxis can produce severe symptoms in as little as 5 to 15 minutes, although life-threatening reactions may progress over hours. Signs of such a reaction include: difficulty breathing, feeling of impending doom, swelling of the mouth and throat, a drop in blood pressure, and loss of consciousness. The sooner that anaphylaxis is treated, the greater the person's chance of surviving. The person should be taken to a hospital emergency room, even if symptoms seem to subside on their own.
What do you do if you suspect a food allergy? To diagnose food allergy a doctor must first
determine if the patient is having an adverse reaction to specific foods. This
assessment is made with the help of a detailed patient history, the patient's
diet diary, or an elimination diet.
How to Cope with Food Allergies:
What should you do if you suspect you have a food allergy? You'll likely need to avoid the bothersome food - and be cautious when choosing your meals and snacks. If you must do away with a food, or category of food, plan carefully to ensure that your eating plan is nutritionally adequate and fits your food preference and lifestyle. Be sure to read food labels for allergens. Let's take eggs for example. If you're allergic to eggs, you'd need to know that eggs are common ingredients in mayonnaise, many salad dressings, and ice cream. Take a look at this list to see different names for food you may be allergic to.
Milk and soy allergies are particularly common in
infants and young children. These allergies sometimes do not involve hives and
asthma, but rather lead to colic, and perhaps blood in the stool or poor growth.
Infants and children are thought to be particularly susceptible to this allergic
syndrome because of the immaturity of their immune and digestive systems. Milk
or soy allergies in infants can develop within days to months of birth.
Sometimes there is a family history of allergies or feeding problems. The
clinical picture is one of a very unhappy colicky child who may not sleep well
at night. The doctor diagnoses food allergy partly by changing the child's diet.
MORE INFORMATIONFor more information about food allergies, contact the following groups: The Food Allergy Network American Academy of Allergy, Asthma and
Immunology Physician Referral Hotline
Activity 3:
Where
are you taking today's lesson?
You have completed the lesson on “Food Allergies”.
If you have any questions or comments, please e-mail one of our
nutritionists. We’ll be glad
to answer any of your questions. * If you have an extra minute, please fill out our survey on the WIC home page (where you chose this class) so we can better serve you. Thank You. Answers:
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||