Ulcerative colitis: can a Mediterranean diet reduce the frequency of relapses?

Rich in legumes (lentils, beans, chickpeas, etc.), whole grains, fruits, vegetables, nuts, seeds and olive oil, the Mediterranean diet (sidenote: Mediterranean diet Rich in fruit, vegetables, cereals, oilseeds (nuts) and fish, and low in red meat, saturated fats and dairy products. Lăcătușu CM, Grigorescu ED, Floria M, et al. The Mediterranean Diet: From an Environment-Driven Food Culture to an Emerging Medical Prescription. Int J Environ Res Public Health. 2019 Mar 15;16(6):942. ) is also characterized by moderate consumption of fish, poultry and dairy products and low consumption of processed foods and red meat. This particularly healthy diet involves a high intake of dietary fiber and beneficial compounds (notably the famous polyphenols found in grapes, nuts and olives) and a better balance of fats (fewer saturated fatty acids). It provides health benefits to its followers, including patients suffering from ulcerative colitis (sidenote: Ulcerative colitis Ulcerative colitis is a chronic disease of the large intestine (colon) characterized by inflammation (redness and swelling) and ulcers (sores) along the lining of the colon, which can cause abdominal pain, cramping, bleeding and diarrhea. Along with Crohn’s disease, ulcerative colitis is one of the chronic inflammatory bowel diseases (CIBD) that affect 10 million people worldwide. (source: Canadian Digestive Health Foundation).   ) (a real intestinal nuisance), based on the results of a recent clinical study. And this was not just any trial, but a randomized (sidenote: Randomized trial Study in which the products tested are distributed randomly, between the participants. ) controlled trial (sidenote: Controlled trial a study in which participants are given either a test product (capsule containing the active compound) or a placebo (control capsule not containing the active compound), thus allowing for comparison. ) , i.e., the Holy Grail of studies offering the highest level of evidence of a possible effect.

Reducing the frequency of ulcerative colitis relapses

In practice, this study, carried out by researchers at the University of British Columbia, compared the effects of a typical Western diet (low in fruit, vegetables and legumes, high in meat, etc.) and a Mediterranean diet, in patients suffering from ulcerative colitis. And what did the results show? The Mediterranean diet seems to reduce the frequency of attacks for patients in remission and lessen the severity of relapses. A mild resumption of the disease was observed in one out of three patients after three months on the Mediterranean diet, while almost half of the patients who maintained their usual Western diet had the disease return with mild to moderate activity.

_{Sources (sidenote: Source : World Gastroenterology Organisation Global Guidelines, 2015 )}

The protective effect of gut microbiota 

What accounts for such a protective effect? The most likely reason involves the gut microbiota. The Mediterranean diet goes hand in hand with the growth of protective bacteria that produce more health-promoting short-chain fatty acids (sidenote: Short chain fatty acids (SCFA) Short chain fatty acids (SCFA) are a source of energy (fuel) for an individual’s cells. They interact with the immune system and are involved in communication between the intestine and the brain. Silva YP, Bernardi A, Frozza RL. The Role of Short-Chain Fatty Acids From Gut Microbiota in Gut-Brain Communication. Front Endocrinol (Lausanne). 2020;11:25. ) and reduce the number of potentially pathogenic bacteria. Secretions from the mucous membranes lining the intestine could play a role. Amplified by the Mediterranean diet, these secretions are thought to prevent pathogenic bacteria from gaining access to the intestinal epithelium.

These results encourage ulcerative colitis patients to take advantage of periods of remission of their disease to adopt a Mediterranean diet. This dietary boost is well tolerated during these lulls but should not replace their medical treatment!