People with Crohn’s disease often ask a simple but important question: “What should I eat?” For many years, doctors haven’t had clear answers.
That’s because it’s been difficult to study how diet affects this disease, and most research so far hasn’t given strong evidence to support specific food plans.
Now, researchers at Stanford Medicine have found promising results that could help. In a national clinical trial, a special kind of short-term diet called a “fasting mimicking diet” showed clear improvements in symptoms and signs of inflammation in people with mild-to-moderate Crohn’s disease. The findings were published in the journal Nature Medicine.
Crohn’s disease is a long-term condition that causes inflammation in the digestive system. It affects about one million people in the United States. People with Crohn’s often have stomach pain, diarrhea, cramping, and weight loss.
Current treatment for mild Crohn’s disease usually involves steroids, but those drugs can have serious side effects if used for too long. There are no widely accepted diet-based treatments.
The study tested 97 people across the country. Sixty-five of them followed the fasting mimicking diet, and the other 32 continued eating their normal meals.
The fasting mimicking group ate a low-calorie, plant-based diet for five days each month. During those five days, they ate between 700 and 1,100 calories per day. For the rest of the month, they went back to their normal diet.
By the end of the study, about two-thirds of the people who followed the fasting diet saw an improvement in their symptoms. Even after just one round of the diet, some patients reported feeling better.
In comparison, fewer than half of the people in the control group felt any improvement. Those results may have happened naturally, or as part of their regular medical treatment.
Some people in the fasting group did feel tired or had headaches, but no serious problems were reported. More importantly, the researchers didn’t just look at how people felt. They also checked changes in their blood and stool to see if there were real improvements inside the body.
They found that people who followed the fasting mimicking diet had lower levels of a protein called fecal calprotectin, which shows how much inflammation is in the gut. Other signs of inflammation, including molecules in blood and immune system signals, were also lower in the fasting group.
Dr. Sidhartha Sinha, who led the study, said these findings are exciting because they offer new hope for people with Crohn’s. He was encouraged by earlier studies that showed the same diet helped reduce general inflammation, and he believed it might work for Crohn’s too.
The team is now studying how the diet might change the bacteria in the gut—the microbiome—and whether that explains why some people respond better than others. They hope to find ways to predict which patients will benefit the most from the diet.
The research was done with help from scientists at the University of Southern California and the University of California, San Francisco. One of the authors, Dr. Valter Longo, is linked to the company that provided the meals used in the study and has filed patents related to the diet.
While more research is needed, this study shows that the right diet could one day be an important part of Crohn’s disease treatment—helping patients feel better and reduce gut inflammation without relying only on medications.
For more information about gut health, please see recent studies about the crucial link between diet, gut health, and the immune system and results showing that Low-gluten, high-fiber diets boost gut health and weight loss.
For more information about gut health, please see recent studies about Navigating inflammatory bowel disease (IBD) with diet and results showing that Mycoprotein in diet may reduce risk of bowel cancer and improve gut health.
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