Eating vegetables and whole grains reduces the risk of Crohn’s disease, while eating more fruit and beans/legumes lowers the risk of ulcerative colitis (UC), according to researchers in Canada. In turn, refined grains could promote disease, their findings suggest.
The study, “Differences in adiposity and diet quality among individuals with inflammatory bowel disease in Eastern Canada,” appeared in the journal PLOS ONE.
Patients with Crohn’s, one of the main forms of inflammatory bowel disease (IBD), frequently have abnormal adipose (fat) tissue in the mesentery — a fold of membrane attaching the intestine to the abdominal wall — as well as excess intra-abdominal and visceral fat, which contributes to inflammation.
Besides the adipose tissue, diet also regulates the gut microbiome — the bacteria, viruses, and fungi that can further promote inflammation — but it may help manage IBD symptoms.
However, clinicians still lack large epidemiological studies assessing diet and obesity in patients with IBD.
While exercise is known to reduce inflammation and maintain muscle mass and strength, IBD patients may find that regular physical activity and managing their disease symptoms is a challenge.
The research team from Dalhousie University in Halifax, Nova Scotia, hypothesized that IBD patients have a poorer diet and greater abdominal fat compared to those without the disorder.
The scientists studied the association between body composition and lifestyle in Crohn’s and UC — the other main form of IBD — in patients from Atlantic Canada (New Brunswick, Nova Scotia, Newfoundland and Labrador, and Prince Edward Island), which has the highest incidence of IBD in the world.
The study included 111 Crohn’s patients, 119 UC patients, and 12,462 people without IBD. All completed a questionnaire about dietary habits and had their height, weight, grip strength and body composition measured. To assess obesity, the team calculated body mass index (BMI) and waist-to-hip ratio.
Participants were classified as living in urban or rural areas, with their sex, age, province and income included. The researchers collected lifestyle data, including sleep, physical activity, smoking, and alcohol consumption.
The results showed that a greater number of participants with IBD reported multiple chronic conditions. In particular, those with ulcerative colitis had higher weight and BMI compared to those without IBD.
Patients with either Crohn’s or UC reported eating more refined grains than those without IBD. Refined grains are processed starches broken down to increase shelf life. The process, known as milling, drains dietary fiber, iron, and B vitamins. Refined grains include white flour, white bread, and white rice.
The data also showed that higher levels of fat were associated with more servings of refined grains, meat, poultry, eggs, and fish. The highest consumption of vegetables, fruit, whole grains, tofu, nuts and seeds was associated with lower amounts of fat.
The analysis showed that participants who ate more vegetables and whole grains had reduced risk of developing Crohn’s, while eating more fruits and beans or legumes lowered the chance of UC.
In line with these findings, prior research showed that eating whole grains instead of refined ones improves the gut microbiota and reduces inflammation.
Patients with IBD reported similar levels of activity than those without the disease. Grip strength and smoking habits were also similar.
“Distinct differences in adiposity and diet quality were observed in individuals with specific types of IBD compared to those without,” the researchers wrote. “There is a need for collaborative efforts to address weight management and diet quality issues in those living with IBD in the Atlantic Canadian region.”