Dr Ananthakrishnan reviews data from prospective studies on how diet can increase the risk of developing inflammatory bowel disease.

Ashwin Ananthakrishnan, MD, is director of the Crohn's and Colitis Center at Massachusetts General Hospital and an associate professor at Harvard Medical School in Boston, Massachusetts.

TRANSCRIPT:

 Dr. Ashwin Ananthakrishnan, MD, MPH:  Hi, I'm Dr. Ashwin Ananthakrishnan. I'm an Associate Professor of Medicine at Massachusetts General Hospital. At this year's Crohn's and Colitis Congress, I reviewed data looking at diet as risk for IBD.

There are many pieces of evidence that point towards diet playing a very important role in the development of inflammatory bowel disease. Globally, if you map out evolution in our diet over the past 40 or 50 years, this have largely paralleled the increase we're seeing globally in incidence of Crohn's disease and ulcerative colitis. In addition, if you ask any patient what their most common trigger is, they will point to diet.

What we reviewed over the course of this talk was focusing on prospective cohorts which look at very large numbers of people, often 50,000 to 100,000 patients, or healthy men or women who were followed for several years to look at who developed Crohn's disease and ulcerative colitis, with very systematic assessment of diet over the same time point.

These studies so far have shown that a diet that is high in fiber was associated with a lower risk of Crohn's disease, particularly if the fiber was from fruits and vegetables. This is well supported by experimental data, where fruit and vegetable content improves your intestinal barrier function and also results in some proliferation of anti-inflammatory microbes in your gut.

Studies have also shown that a diet that is high in N-3 polyunsaturated fatty acids, these are typically found in marine food, is associated with a lower risk of ulcerative colitis. Studies have also shown that dietary patterns are important.

There was a large study that was published a year ago, which showed that a Mediterranean-style diet was associated with a lower risk of Crohn's disease, particularly in developing Crohn's disease at an older age. Studies have also looked at how food processing affects risk of Crohn's disease and ulcerative colitis.

This is supported by experiments where if you add emulsifiers and other additives to the feed of rats, that they're more likely to develop colitis. This is because they develop changes in their intestinal microbiome and in their immune function.

Over the course of this past year, there were two large studies that were conducted in diverse settings that showed that a diet that was high in consumption of ultra-processed foods was at a higher risk of developing Crohn's disease. This was particularly for things like ultra-processed breads and breakfast foods and sugars and sweet snacks.

This suggests that again, that in addition to just watching the content of our food, we also need to be aware that potentially food processing could play a role in our risk as well. That was the role of diet in the development of IBD.