But many people who suffer more chronic, long-term symptoms - head and muscle aches, swellings, minor infections and poor sleeping patterns - suspect that certain foods may be to blame. They are given short shrift by many conventional doctors. Some may be referred to food elimination programmes, but these can be laborious and results are not always satisfactory.
In the past few months, a new technique developed in the US has become available in this country. It can test a blood sample for an allergic reaction to more than 100 foods. It is alleged to be reliable, with a 95 per cent consistency on split sample trials (blood from one person is divided into two samples and sent for analysis under two different names).
Martha Trothe, 49, decided to try the test after food elimination programmes failed to help. "I suffered from pains in my bones and joints," she recalls. "I would have put up with it, but then I started getting bloating and swelling around my face and stomach. My vanity said I had to do something. I'd put on about three stone."
Martha sent her blood sample to Higher Nature, a specialist in nutritional supplements based in Sussex, who passed it on to Immuno Laboratories in Fort Lauderdale, Florida, a leading allergy testing centre approved by the Food and Drugs Administration. The laboratory has tested more than 100,000 people.
Martha's results showed she was allergic to 24 foods including bananas, bread, cod, yeast, eggs, kidney beans, sugar, pineapples and pepper. "I had to cut all of them out of my diet for three months. It's been a bore at times, but the results have been amazing."
Without reducing food intake or counting a single calorie, she has lost 23 pounds. She is no longer bloated, her bone pains are gone, and her mood has greatly improved. According to Dr James Braly, author of the American best-seller Food Allergy and the Nutrition Revolution, hidden food allergies lie at the root of chronic conditions such as rheumatoid arthritis, migraines and panic attacks. He and other food allergists believe our digestive system is the key to our health. When it is working properly, allergies are not a problem but factors such as stress, refined foods, high fats and antibiotics can reduce its efficiency. When this happens, partially digested food particles can leak into the bloodstream.
IgG antibodies, part of the B lymphocytes system, "tag on" to these food particles, "telling" clean-up cells in the blood to remove them. It is the presence of these tags in the blood that Immuno Laboratories test detects. When the removal system gets overwhelmed, tagged particles can produce a range of symptoms - runny noses, stiff joints and constricted blood vessels.
Unlike the IgE system, IgG antibodies only have a memory of about two to three months, so once digestive problems have been sorted out, troublesome foods may be re-introduced.
The Immuno test costs pounds 295. Higher Nature can be contacted at Burwash Common, East Sussex TN19 7LX. Telephone: 01435 883 484.Reuse content