CHICAGO (Reuters) – Contrary to popular belief and common medical advice, eating seeds, nuts, corn and popcorn does not cause the bowel disease diverticulosis or its painful complications, researchers said this week.

In fact, nuts and popcorn may even provide some protection from the complications and those who avoid nuts may be depriving themselves of valuable nutrients, said Dr. Lisa Strate and colleagues at the University of Washington School of Medicine in Seattle.

Their findings came from a look at more than 47,000 male US medical professionals who were followed for a variety of health issues for 18 years beginning in 1986.

Diverticulosis is the development of small pouches in the colon that bulge outward through weak spots. In the United States, about 10 percent of the population over age 40 has the condition and, by age 60, about half of the population is affected, according to the National Institute of Diabetes, Digestive and Kidney Diseases (NIDDK).

Many have no symptoms but 10 to 25 percent of those with diverticulosis can have attacks of diverticulitis caused by inflammation in the pouches.

The University of Washington team, in a report published in this week's Journal of the American Medical Association, said there was no scientific evidence that eating seeds, nuts, corn or popcorn raises the risk for diverticulosis.

But they noted a recent survey of colorectal surgeons found that nearly half felt their patients should avoid those foods.

The researchers said they found 801 new cases of diverticulitis and 383 new cases of diverticular bleeding among the men over the course of the study.

Men who ate nuts twice a week or more had a 20 percent lower risk of diverticulitis than those who ate them less than once a month, and men who ate the most popcorn had a 28 percent lower risk of diverticulitis, they found. The findings show "nut, corn and popcorn consumption did not increase the risk of diverticulosis or (its) complications," the report concluded.

The NIDDK, one of the National Institutes of Health, advises that eating a high-fibre diet is the key to colon health, and that nuts and such seeds as tomato, zucchini, strawberry, raspberry and poppy are considered harmless.