Worried about diverticulitis, the painful inflammation of abnormal pouches in your intestines? Eat more like a vegetarian, new research suggests.
Some prior studies have implicated too much meat or too little fiber in the diet as contributors to diverticular disease. So British researchers led by Francesca Crowe, PhD, of the University of Oxford compared the risk of diverticulitis and related conditions among 47,033 participants in the EPIC-Oxford study, one-third of whom were vegetarians.
The participants filled out a 130-item food-frequency questionnaire to assess their diets. The vegetarians in the study tended to be younger-average age 40 for men, 36 for women-than the meat-eaters, who averaged age 50 for men and 47 for women. Over an average followup period of 11.6 years, there were 816 cases of diverticular disease in the total study group.
Vegetarians were 31% less likely than meat-eaters to develop the disease and less likely to be admitted to the hospital or die from the condition; vegans were at even lower risk. There was little connection between actual meat-eating amounts and risk, however, suggesting that vegetarians benefited from other components in their diet, including more fiber. Overall, those eating the most fiber among all participants were at 42% lower risk, and even meat-eaters with the highest fiber intake were at 26% lower risk than their peers who ate the least.
Why might vegetable and fiber be associated with lower prevalence of diverticular disease? Consuming lots of vegetables and fiber helps hold on to water and prevent constipation. Crowe and colleagues suggested that by speeding passage of food through the gastrointestinal system, these foods could reduce internal pressure in the intestines, reducing the risk of forming pouches or bulges (diverticula) in weakened intestinal walls. Eating lots of meat, the researchers added, might also alter the metabolism of colon bacteria in a way that weakens the intestinal walls.
While not calling for a wholesale conversion to vegetarianism, Crowe and colleagues concluded that their findings lend support to public health recommendations that encourage the consumption of foods high in fiber such as whole meal breads, whole grain cereals, fruits and vegetables.
Robert M. Russell, MD, a gastroenterologist and emeritus professor in Tufts Friedman School, adds an important reminder: This is good as far as it goes, but if one already has intestinal narrowing from established diverticulitis, then the opposite is true: A low fiber/roughage (residue) diet is needed.
In an editorial accompanying the study in BMJ, David Humes, MD, and Joe West, MD, both of Nottingham University Hospitals, also cautioned against reading too much into the results. They noted the large percentage of younger females in the study population-a group less likely to be diagnosed with diverticular disease in any case, which tends to develop in older patients. They also calculated that 71 meat eaters would have to convert to vegetarianism, according to the results, to prevent just one diagnosis of diverticular disease.
TO LEARN MORE: BMJ; abstract at www.bmj.com/content/343/bmj.d4131.abstract.