DDW: Popcorn and Nuts Exonerated in Diverticulosis

WASHINGTON, May 21 -- Forget that time-honored advice to diverticulosis patients to shun hard-to-digest foods like nuts and popcorn, said investigators here.

Indeed, evidence from a large cohort of health professionals suggests that popcorn may even have a protective effect against the complications of diverticulosis, Lisa Strate, M.D., of the University of Washington in Seattle, said during Digestive Disease Week sessions.

Those complications -- infection, inflammation, and bleeding -- affect between 10% and 30% of patients with diverticulosis, she said, and can require hospitalization.

To avoid that, doctors have warned patients to stay away from nuts, corn, and popcorn, even though some of those foods -- nuts in particular -- are known to have health benefits.

"The recommendation has evolved over the past 60 or 70 years," Dr. Strate said. "It simply stems from a theory that trauma was one of the causes of diverticular complications and that these foods would be more likely to traumatize the colon wall."

To test the theory, Dr. Strate and colleagues turned to the long-running Health Professionals Follow-up Study, which enrolled more than 50,000 men between the ages of 40 and 75.

Starting in 1986, men with newly diagnosed diverticular disease or complications were sent supplemental questionnaires asking of details of treatment and diagnosis. Dr. Strate said.

The records have been collected since 1986 but no one looked at them until now, Dr. Strate said.

Analyzing the 47,454 men who were free of diverticular disease at baseline she and colleagues found there were 383 new cases of diverticular bleeding and 801 new cases of diverticulitis after 18 years of follow-up.

Using the 131-item dietary questionnaires filled out by participants every two years, they divided the cohort into those who ate nuts, corn or popcorn frequently (two or more times a week) and those who did so rarely (less then once a month).

A multivariate analysis showed that:

• Eating nuts frequently was associated with a 20% reduction in the risk of diverticular complications (no tests of statistical significance were provided).
• Men with the highest popcorn intake (at least two times per week) had a hazards ratio for diverticular complications of 0.71 (95% CI 0.56-0.90; P for trend 0.18) when compared to men with the lowest popcorn intake (less than once per month).
• And there was no association between any of the three foods and diverticular bleeding.

For doctors, the take-home message is that patients who enjoy nuts and popcorn should keep on eating them, she said, although she said it's probably too early to recommend popcorn as a protection again the disease.

The finding is good news for patients who like popcorn, said Maria Abreu, M.D., of Mount Sinai in New York, who moderated a press conference where Dr. Strate discussed her findings.

A significant proportion of older Americans has diverticulosis "and they've all been told by their doctors to strictly avoid nuts and corn and popcorn," said Dr. Abreu, a gastroenterologist who was not involved in the research.

"When patients come in who've eaten any of those foods any time in the past year, their episode of diverticulitis or bleeding is blamed on the popcorn," she said.