Food Allergy and its causes

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Ever had a rash, stomach problem or respiratory ailment that defied diagnosis? You might have been suffering from a hidden food reaction.

Up to 1% of adults and 7% of children under age five have at least one food allergy an abnormal immune system response triggered by exposure to “foreign” proteins.

Food allergies can produce severe symptoms. Severe cases can lead to anaphylactic shock.

Leading causes of food allergy

Fish (including shellfish), cow’s milk, eggs, wheat (including bread and pasta), peanuts, tomatoes, spinach, strawberries, raspberries, oranges and mangoes.

It’s estimated that 5% to 50% of all adults suffer from a related problem called food intolerance. This adverse reaction does not involve the immune system but it produces similar symptoms.

Many cases of food intolerance are caused by a lack of one or more digestive enzymes. This deficiency impairs the body’s ability to break down certain proteins in food.

Leading causes of food intolerance:

Lactose sulfites, artificial colors, food additives like monosodium glutamate, histamines (compounds in fermented foods like cheese, sauerkraut, alcoholic beverages and vinegar), tyramine (an amino acid in aged cheeses, yeast extract, wine, beer, raspberries and bananas) and food preservatives like benzoic acid and sodium benzoate.

Pinpointing food reaction

Food allergies and intolerances manifest themselves differently in different people. A food that might give one person a rash might give another stomach pain.

Predictably, doctors often have a hard time pinpointing the trouble. Misdiagnoses are very common.

If you suspect certain foods are making you ill, ask your doctor to refer you to a food-allergy specialist someone experienced in the use of the “elimination and challenge diet.”

This diet the only surefire way to pinpoint food reactions has two phases. During the four-week elimination phase, all suspect foods are off limits. Symptoms often begin to clear up during this phase.

During the ensuing challenge phase, lasting a few weeks to a few months, suspect foods are reintroduced one at a time. The patient watches carefully to see if symptoms return.

Here are four case histories illustrating the most common and commonly overlooked food allergies and intolerances

Case history #1

Jack, a 48-year-old salesman, had a long history of headaches, bloating, gas and abdominal pain. His symptoms usually began an hour or so after breakfast and lasted all day. He also complained of constant fatigue and was having difficulty concentrating.

Jack exhibited no signs of gastrointestinal disease and had regular bowel movements. He went on a diet that excluded wheat, rye, oats, and barley, corn and milk products. (He took an 800-mg calcium supplement to make up for the lost calcium.) In addition, he ate no raw fruit or vegetables only cooked or canned were permitted and no whole nuts or seeds.

After four weeks, Jack was “challenged” with each of the above foods. It turned out he was allergic to wheat, raw fruits and vegetables and highly fermented foods (cheese, wines, and beer).

Now that Jack avoids these foods, his symptoms have abated. His energy has increased threefold, he says.

Case history #2

Mary, a 50-year-old nurse, was troubled by constipation, mood swings and leg cramps. She was also concerned about the poor condition of her nails and teeth.

She was taking a variety of medications including herbal supplements and an antidepressant. Nothing seemed to help.

Mary’s symptoms suggested an intolerance or allergy to several different foods. Indeed, an elimination diet revealed allergies to food additives, wheat and dairy products.

After giving up these foods for three months, her physical and emotional health improved. Within six months Mary was no longer constipated. She felt better than she had in 10 years.

Case history #3

A 62-year-old telephone company employee named Virginia had a history of asthma and hay fever dating back to childhood. She was also bothered by stomach upset, flaky skin on her hands and feet and a dangerously elevated cholesterol level.

Though she had been on a restricted diet, Virginia couldn’t shake her symptoms. Then a series of elimination and challenge tests revealed sensitivity to certain nuts and seeds, wheat and dairy products.

Within months of giving up these foods, Virginia’s symptoms had disappeared, and her cholesterol level had fallen to normal.

Case history #4

Rita, a 56-year-old computer worker, was plagued by diarrhea, gas and abdominal pain. She’d had these problems since childhood, but they had intensified over the past year.

When a thorough exam revealed no underlying illness, Rita was put on a diet that excluded grains, starches and sugar.

In the next four weeks, she reported only two episodes of diarrhea and each occurred after she cheated on her diet. Subsequent challenges showed that she was affected adversely by foods containing refined sugar.

Having given up these foods permanently, Rita is now completely free of symptoms.

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