Food allergies tied to irritable bowel syndrome

People with Irritable bowel syndrome have high levels of antibodies that indicate they are allergic to common foods like wheat, beef, pork, and lamb, a new study suggests.

Irritable bowel syndrome (IBS) is a condition causing constipation or diarrhea (or sometimes both, cyclically), cramping and generalized gut discomfort. Because no clear physical cause has been discovered, it has been thought that stress and mental disorders play a role.

“Food hypersensitivity is a common perception among IBS patients,” Dr. Devinder Kumar, of St. Georges Hospital Medical School in London, UK, and colleagues write in the American Journal of Gastroenterology.

Irritable bowel syndrome Definition
Irritable bowel syndrome refers to a complex disorder of the lower intestinal tract. It is mainly characterized by a pattern of symptoms that is often worsened by emotional stress. The condition involves hypersensitivity to pain in the gut, combined with altered bowel habits resulting in diarrhea, constipation, or both.
Causes, incidence, and risk factors

Irritable bowel syndrome is characterized by a combination of abdominal pain and altered bowel function. There are many possible causes. For instance, there may be a disturbance in the muscle movement of the intestine or a lower tolerance for stretching and movement of the intestine. There is no abnormality in the structure of the intestine.

Irritable bowel syndrome (IBS) can occur at any age, but often begins in adolescence or early adulthood. It is more common in women. Predisposing factors may include a low-fiber diet, emotional stress, use of laxatives, a bout of infectious diarrhea, or other temporary bowel inflammation.

Irritable bowel syndrome is extremely common, but only a small proportion of people seek treatment.

The idea of food allergy as a cause is supported by studies that systematically eliminated certain dietary components and then reintroduced them to see how symptoms were affected, the team explains, “but there are no well-established tests to identify food hypersensitivity.”

The researchers compared levels of antibodies to common foods in 108 patients with irritable bowel syndrome and a comparison group of 43 unaffected “control” subjects. As well as the antibody measurements, the researchers also conducted skin prick testing to 16 common foods including milk, eggs, cheese, wheat, rice, potatoes, various meats, and soya beans.

Antibody levels to wheat, beef, pork, lamb and soya beans were significantly higher in IBS patients, and tended to be higher for egg yolk and egg white, Kumar and colleagues found.

However, they didn’t see any “significant correlation” between symptom severity and frequency and antibody levels.

Nonetheless, the researchers note that elevated levels of food-specific antibodies have been seen in asthma, which suggests there could be a similar process going on in irritable bowel syndrome.

SOURCE: American Journal of Gastroenterology, July 2005.

Provided by ArmMed Media
Revision date: July 3, 2011
Last revised: by Sebastian Scheller, MD, ScD