For the study, researchers asked 84 people with ulcerative colitis (UC) and 58 people with Crohn’s disease to follow a Mediterranean diet for six months. They all received dietary guidance from a nutritionist, who counseled them on how to follow a Mediterranean diet and how to space food intake out over two snacks and three meals a day; people with obesity also got advice on cutting calories. At the start of the study 14 patients with ulcerative colitis and nine patients with Crohn’s disease who had stable therapy throughout the study period and complete follow-up labs had active disease. Six months later, only four people with ulcerative colitis and two with Crohn’s disease had active disease, and all of these cases were mild, the study found. Patients also completed quality of life questionnaires at the start and end of the study, and reported improved quality of life after six months on the Mediterranean diet. “These results matter to the patients with active disease because of the debilitating effects such as abdominal pain and diarrhea they have to endure on a daily basis,” says Moon Han, PhD, MPH, a scientist at the Centers for Disease Control and Prevention (CDC) in Atlanta, who wasn’t involved in the study. “So, any measure of relief is important to these patients,” Dr. Han says. RELATED: Another Benefit of a Mediterranean Diet for Older Adults May Be Better Sleep, Study Suggests During the study period, ulcerative colitis patients’ body mass index (BMI) decreased by an average of 0.42 points to 25.3 and their average waist circumference declined 1.25 centimeters. Over this same time frame, Crohn’s disease patients’ BMI dropped by an average of 0.48 points to 24.6 and their waist circumference decreased by 1.37 centimeters. The number of ulcerative colitis patients affected by an accumulation of fat around the liver, or steatosis, declined from 31 at the start of the study to 18 by the end, while the number of Crohn’s disease patients with this problem dropped from 27 to 18. “Long-term consumption of [a] Mediterranean diet reduces levels of inflammation and improves metabolic health,” says Krasimira Aleksandrova, PhD, a scientist at the German Institute of Human Nutrition Potsdam-Rehbruecke in Nuthetal, who wasn’t involved in the study. A typical Mediterranean diet is rich in fruits, vegetables, legumes, whole grains, fish, and healthy fats like olive oil — many foods that have anti-inflammation properties, Dr. Aleksandrova says. By contrast, a typical Western diet heavy in red and processed meats, sugars, and unhealthy fats can increase inflammation. As a result, switching to a Mediterranean diet may help many people reduce inflammation and IBD flare-ups, Aleksandrova says. RELATED: A Mediterranean Diet May Alter the Gut Microbiome to Improve Longevity
Other Benefits of a Mediterranean Diet
A study published in June 2020 in Gut also suggested that a Mediterranean diet might help prevent some people from developing IBD. The study followed 83,147 Swedish adults who didn’t have IBD for up to 17 years, using food questionnaires to see how closely participants followed a Mediterranean diet. People who most closely adhered to the diet were 58 percent less likely to develop Crohn’s disease. However, this diet didn’t appear to impact the risk of ulcerative colitis. One limitation of the newest study is the lack of a control group of IBD patients who didn’t follow a Mediterranean diet, says lead study author Fabio Chicco, a resident in gastroenterology at Cagliari State University in Italy. “We can’t rule out that clinical improvement occurred, in some patients, independently of the dietary intervention,” Chicco says. RELATED: Your Everyday Guide to Living Well With Ulcerative Colitis
Mediterranean Diet Adherence Unclear
Other limitations include the reliance on 24-hour diet recall questionnaires to assess what people ate, which don’t always accurately capture the type or amount of foods people eat. In addition, it’s not clear from the study how closely participants followed a Mediterranean style diet. Still, a Mediterranean diet has been shown to reduce inflammation as well as block pathways that tend to make people store more fat in their bodies, including in their liver. And this may benefit IBD patients, says Andrew Chan, MD, MPH, a professor of medicine at Harvard Medical School and gastroenterologist at Massachusetts General Hospital in Boston. “If someone follows a Mediterranean diet, it might mean lower levels of inflammation that could reduce disease activity in patients with IBD and also reduce the amount of fat stored in the liver and other parts of the body,” says Dr. Chan, who wasn’t involved in the study. To help minimize the risk of symptom flare-ups that can result from a radical change in eating habits, patients should still check with a doctor to see if a Mediterranean diet makes sense for their circumstances, Chan advises. “The take-home message is that if you have IBD, it might not be a bad idea to try to adopt a Mediterranean diet, especially since it is likely to be associated with other health benefits,” Chan says. “However, further evidence is needed to make it a formal recommendation.”
