26/08/08 Contrary to a common recommendation to avoid eating popcorn, nuts and corn to prevent diverticular complications, a large prospective study of men indicates that the consumption of these foods does not increase the risk of diverticulosis or diverticular complications, according to a study in the August 27 issue of JAMA.

Diverticular disease is a common and costly digestive disorder in Western countries. One-third of the U.S. population will develop diverticulosis by the age of 60 years and two-thirds will do so by the age of 85 years, according to background information in the article. Historically, physicians have advised individuals with diverticular disease to avoid eating nuts, corn, seeds and popcorn, even though there is little evidence to support this recommendation. The authors write that the potential health benefits of nut consumption paired with the large number of individuals with diverticulosis makes it timely and important to study this long-held belief.

Lisa L. Strate, M.D., M.P.H., of the University of Washington School of Medicine, Seattle, and colleagues examined the association between nut, corn, and popcorn consumption and diverticular disease in a large study group (The Health Professionals Follow-up Study), a group of men followed up from 1986 to 2004 via self-administered questionnaires about medical (once every two years) and dietary (every 4 years) information. Twenty-seven percent of participants reported eating nuts at least twice per week, and corn and popcorn each were consumed at least twice a week by 15 percent of the participants.

The study included 47,228 men age 40 to 75 years who at baseline were free of diverticulosis or its complications, cancer, and inflammatory bowel disease. During 18 years of follow-up, there were 801 new cases of diverticulitis and 383 new cases of diverticular bleeding.

The researchers found that nut, corn, and popcorn consumption was not associated with an increased risk of new diverticulitis or diverticular complications, but instead inverse relationships were observed between nut and popcorn consumption and the risk of diverticulitis. After adjustment for other known and potential risk factors for diverticular complications, men with the highest intake of nuts (at least twice per week) had a 20 percent lower risk of diverticulitis compared with men with the lowest intake (less than once per month); men with the highest intake of popcorn had a 28 percent lower risk of diverticulitis compared with men with the lowest intake. No association was seen between corn consumption and diverticulitis, and for diverticular bleeding, there were no significant associations observed for nut, corn, or popcorn consumption.

"In conclusion, our results suggest that nut, corn, and popcorn consumption is not associated with an increased risk of incident diverticulitis or diverticular bleeding and may be protective for the former. These findings refute the pervasive but unproven belief that these foods are associated with diverticular complications and suggest that the recommendation to avoid these foods in diverticular disease should be reconsidered," the authors write.