Diets are effective in treating Crohn's disease

Stan Cohen

A study comparing the Mediterranean and Specific Carbohydrate Diets showed both work about 40% of the time to achieve what's known as symptomatic remission (JD Lewis and others, Gastroenterology 2021). What's more, over 30% had improvement in one of the important markers of internal disease activity at 6 weeks into the study. Improvement was seen in pain levels, tiredness (fatigue), and the way participants rated their quality of life. All of this while those in the study didn't change their medicines or anything else—though it's of note that the majority of those in the trial was on a least one medication during the 12-week trial.

The reason for doing the trial comparing the 2 diets is interesting in itself. Earlier studies have shown that those on a traditional Mediterranean Diet, which is loaded with fresh fruits, vegetables, nuts, fish, and whole grains, with olive oil as the main cooking oil and spread) lowers the risk of getting Crohn's disease, while the Specific Carbohydrate Diet (which eliminates most sugars and grains) in small studies seems to improve active Crohn's disease.

So investigators at 33 sites around the US enrolled 194 patients in the trial, providing their meals based on one of the diets for the first 6 weeks. Then they let them follow their assigned diet for another 6 weeks, though that was less successful, with few staying on the foods they were supposed to eat and a number of the participants dropped out of the study along the way. 

There are some important lessons here:

• Diets can work, at least to reduce the symptoms of Crohn's disease. And they may help to decrease the inflammation and improve the intestinal health of Crohn's sufferers (Crohnies), though the bacteria in their intestines didn't seem to change much. That too was shown in the trial.
• Following a diet is hard for a lot of people. Even when meals were provided, some people couldn't stay on their diet (though they had signed up for the study). And when they had to follow the diet on their own, few did.
• There wasn't any significant difference in how the diets performed. Both did reasonably well to help those in the study, with over 40% going into clinical remission with improved symptoms. That may not seem convincing to some, but if you realize that 40% got better just by changing what they ate, that's huge. Pain levels, fatigue, and quality of life improved on both diets.
• There is a concern in the medical community that being on a diet may not really affect how a Crohnie's disease is progressing, that they may be reluctant to go onto medication, and those 2 factors could delay someone getting treatment, but during this short trial, Crohn's did not worsen.    
• The authors concluded, that based on this trial, since the 2 diets gave similar results, "the greater ease of following the Mediterranean Diet, and the other health benefits associated with the Mediterranean Diet," may be preferred for Crohnies with mild to moderate symptoms.
• US News and World Reports also rated the Mediterranean Diet as the best overall of the 35 diets they ranked in terms of nutrition, safety, ease of following it, and for conditions ranging from diabetes, heart health and long-term weight loss. 
• There are three other IBD diets that were not compared in this article. Enteral nutrition, which is where a liquid drink is used for all or most of someone's diet for 8-12 weeks for new patients and those in flares. This has mostly been used in kids and teens, with considerable success in Canada and Europe. The second is the Crohn's Disease Elimination Diet (CDED) which is something of a cross between the Specific Carbohydrate Diet and enteral nutrition, though much more emphasis on removing emulsifiers. The third is the Auto-Immune Diet, which is again similar to both the Mediterranean Diet, the Specific Carbohydrate Diet, and the CDED, in that they all encourage increased fresh fruits and vegetables while eliminating processed foods.  

Perhaps the bottom line is that healthy nutrition helps those with Crohn's disease and that the focus of that should be increased fresh fruits and vegetables while eliminating processed foods as much as possible. 

Similar studies of diets in inflammatory bowel disease, in general, and ulcerative colitis are beginning to show similar results.