It’s Not What You Eat: What Actually Causes Ulcerative Colitis

Some foods trigger ulcerative colitis flares, but no foods have been found to cause the disease itself.

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When you think of what causes ulcerative colitis—a chronic inflammatory bowel disease that affects the large intestine—the logical side of your brain may think that because it’s a condition of the digestive system, the culprit must be one’s eating habits.

Surprisingly, it’s not. While there are some foods that may trigger ulcerative colitis flares, such as dairy, alcohol, sugar, caffeinated beverages, or high-fat or spicy foods, your collective diet choices are not what caused it in the first place.

“The precise reasons for ulcerative colitis are unknown, but there are several theories behind disease development,” says Sergey Khaitov, MD, a surgeon specializing in colon and rectal surgery at Mount Sinai Hospital. While no single factor has been proven to trigger ulcerative colitis, here’s what may contribute to its development:

Overactive intestinal immune system. Researchers believe people with ulcerative colitis may experience an abnormal immune reaction in the intestine. Normally, the immune system fights foreign invaders that can make you sick. In people with ulcerative colitis, however, the immune system thinks non-foreign substances, like food and healthy bacteria, are trying to invade. Because it thinks these generally non-harmful things passing through our intestines are foreign invaders, the body fights back by sending white blood cells to the intestinal lining. This continuous, damaging inflammation can lead to ulcerative colitis symptoms.

Family history. Inherited genes may make you more susceptible to developing ulcerative colitis.

Environmental factors may slightly increase the risk of ulcerative colitis. Bacteria, a virus, or some unidentified factor in the environment may trigger an abnormal immune response in people who have ulcerative colitis in their family. Ulcerative colitis can also present after quitting smoking, since nicotine suppresses the immune system.

Even though food may not be the cause of ulcerative colitis, eating a well-balanced diet, along with following your treatment regimen, is an important part of managing and treating ulcerative colitis. A healthy diet can help ease ulcerative colitis symptoms and promote healing.

Ulcerative colitis can’t be cured, but with the right treatment regimen and a healthy lifestyle, it can controlled. The treatment goal is to remain in remission (a period of no symptoms) for the long-term.

“Sometimes patients hear this diagnosis of ulcerative colitis and they think this is the end of the world,” says Todd Linden, MD, a gastroenterologist in New York City. “Things have improved dramatically, and the vast majority of people will be totally in remission, happy and healthy, and unbothered by this for the rest of their lives.”