The researchers from the Harvard Medical School and Brigham and Women's Hospital in Boston say that nuts are rich in several compounds that may protect against gallstone disease.
They prospectively studied nut (peanuts, other nuts, and peanut butter) consumption in relation to the risk of cholecystectomy (removal of gallstones) in a cohort of 80 718 women from the Nurses' Health Study who were 30-55 y old in 1980 and had no history of gallstone disease.
As part of the Nurses' Health Study, the women reported on questionnaires mailed to them every 2 y both their consumption of nuts and whether they had undergone cholecystectomy. The women were followed through 2000.
They found that women who consumed more than 5 ounces units of nuts per week had a 25 per cent lower risk of cholecystectomy than did women who never ate nuts or who ate less than 1 ounce per month.
In analyses examining consumption of peanuts and other nuts separately, both were associated with a lower risk of cholecystectomy, write the researchers in the July issue of the American Journal of Clinical Nutrition (vol 80, no 1, 76-81).
About 10-15 per cent of the US population (20 million people) have gallstones, and 1 million new cases are diagnosed yearly, according to the US National Institutes of Health.