NEW YORK - Women who regularly eat fruits and vegetables may have lower odds
of developing painful gallstones, the results of a large study suggest.
Of more than 77,000 U.S. women in the long-running Nurses' Health Study,
researchers found that those who ate the most fruits and vegetables were less
likely to require surgery to remove their gallbladder.
Usually, this surgery is performed because of gallstones, masses that develop
when bile stored in the gallbladder hardens into pieces of stone-like material.
These "gallstones" may cause no symptoms, pass through the intestine, or result
in severe pain, block the bile ducts, cause infection, or can even be fatal.
The findings suggest that a diet rich in fruits and vegetables --
particularly leafy greens, citrus fruits and other vitamin-C-rich foods -- can
prevent gallstones from forming or from causing symptoms, Dr. Chung-Jyi Tsai at
Harvard Medical School in Boston and colleagues report in the American Journal
of Medicine.
The results are based on data from 77,090 female nurses who, in 1984, were
between the ages of 37 and 64. They answered dietary questionnaires that year,
and had the rates of gallbladder removal -- called cholecystectomy - were
followed through 2000.
Cholecystectomy is the most common treatment for symptomatic gallstones;
stones that do not cause symptoms are generally left untreated. So rates of
cholecystectomy are indicative of the rate of painful gallstones.
During the study period, Tsai's team found, roughly 6,600 women had their
gallbladders removed. But those with the highest intake of fruits and vegetables
at the study's start were 21 percent less likely than those with the lowest
intake to have the surgery.
The risk reduction was independent of other factors that increase the risk of
gallstone formation, such as age, weight and diabetes.
Women in the group with highest intake of fruits and vegetables typically ate
seven or more servings a day; those with the lowest intake generally ate less
than three servings.
Citrus fruits, leafy green vegetables, and all foods rich in vitamin C seemed
to be particularly protective, the study found. According to the researchers,
dietary fiber, antioxidant vitamins -- which include vitamin C -- and minerals
such as magnesium may all theoretically help prevent symptomatic gallstones.
However, they add, the benefit is likely due to a complex interaction of
nutrients.
"Because any single constituent in fruits and vegetables is unlikely to
explain fully the beneficial effect," Tsai's team writes, "it is reasonable and
practical to recommend an abundant fruit and vegetable consumption."
SOURCE: American Journal of Medicine, September 2006.
