Vegetarian and vegan diets protect against diverticular disease, according to research from the Cancer Epidemiology Unit at the University of Oxford.
The research was part of the European Prospective Investigation into Cancer and Nutrition-Oxford Study (EPIC-Oxford). Participants included 31,574 health-conscious meat eaters and 15,459 vegetarians who filled out comprehensive questionnaires about their diets. After about 11 ½ years, 812 of the subjects had developed diverticular disease.
The researchers—after first adjusting for factors that affect diverticulosis risk like smoking and alcohol intake—found that vegetarian subjects were one-third less likely to have developed the disease. Vegans were more than two-thirds less likely to have diverticular disease, although those findings were based on a very small number of subjects.
Diverticulosis occurs when small pockets or pouches—called diverticula—form in the lining of the large intestine. People with diverticulosis may have no symptoms or may experience some bloating and pain. If the pockets become inflamed—a condition called diverticulitis—symptoms can become much more severe and can include pain, vomiting and fever.
Their increased fiber intake may be part of the reason why vegetarians have less diverticular disease, but meat-free menus might have something to do with it as well. For example, one study found that red meat intake may promote growth of a certain type of bacteria in the colon that produce a toxic compound called a “spasmogen.” These compounds weaken the wall of the colon which can lead to increased formation of diverticula.
To prevent diverticulosis, skip the meat and pile your plate with whole grains, legumes, nuts and seeds, and plenty of fruits and vegetables. For those who already have diverticulosis—which includes about 10% of Americans over the age of 40 and half of those over the age of 60—a diet high in fiber is also the recommended treatment. (In the past, people with diverticulosis were advised to avoid foods like nuts, seeds and popcorn, but newer research suggests that this isn’t necessary.)
Fiber is found only in plant foods, so it’s not surprising that vegetarians generally consume 50 to 100 percent more fiber than the average meat eater and that vegans may consume as much as 2 ½ times more fiber than omnivores.
Source: Crowe FL, Appleby PN, Allen NE, Key TJ. Diet and risk of diverticular disease in Oxford cohort of European Prospective Investigation into Cancer and Nutrition (EPIC): prospective study of British vegetarians and non-vegetarians. Bmj 2011;343:d4131.
Virginia Messina is a dietitian specializing in vegan nutrition. Her new book is Vegan for Life: Everything You Need to Know to be Healthy and Fit on a Plant-based Diet. Learn more about vegan nutrition by reading her blog TheVeganRD, or by following her twitter.