Is Irritable Bowel Syndrome Linked to Foods?
Study Shows Wheat, Beef, Pork, Lamb, and Soybeans Stood Out Among 16 Common Foods
July 14, 2005 -- Are people with irritable bowel syndrome (IBS) more sensitive to certain foods than other people? And if so, what are those foods?
Science doesn't yet have an indisputable answer to that question. But a report in July's American Journal of Gastroenterology may provide more insight.
IBS is a functional condition of the intestine. While no one fully understands what causes IBS, it is not an anatomic problem. According to the American Academy of Gastroenterology, IBS patients have changes in bowel habits, such as constipation or diarrhea. They also have abdominal pain along with other symptoms including abdominal bloating and rectal urgency with diarrhea.
Researchers tested 16 common foods on blood from 132 IBS patients and 43 people without IBS.
IBS patients had higher levels of an antibody called IgG4 in response to five foods, compared with those without IBS. Those five foods were wheat, beef, lamb, pork, and soybeans.
Antibodies are proteins made by the immune system to help fight infections.
IgG is the major antibody in the body; another antibody called IgE is normally present in only trace amounts, but it is responsible for the symptoms of allergy.
However, the study doesn't prove that the five foods caused IBS.
IBS symptom severity and frequency weren't linked to antibody levels, write the researchers. They included Sameer Zar, MRCP, of St. Georges Hospital Medical School in London.
Between one-fifth and two-thirds of IBS patients attribute their symptoms to food hypersensitivity.
By comparison, only about 5% of the general population claims food hypersensitivity.
Sameer Zar, MRCP, and colleagues cite those statistics in their report.
Zar's study included 52 people with diarrhea-prominent IBS, 32 with constipation-prominent IBS, and 24 with alternating IBS.
Most subjects (91) were women. Average age ranged from 35 to about 43.
Foods tested included milk, egg white, egg yolk, cheddar cheese, rice, yeast, potato, peanut, cod fish, chicken, lamb, beef, pork, tomatoes, and soybean.