Nuts, Peanut Butter May Prevent Type II Diabetes

Study finds enthusiasts at 27% reduced risk

TUESDAY, Nov. 26, 2002 (HealthDayNews) -- If you're nuts about nuts, take heart: The more you eat them, the less likely you are to develop Type II diabetes.

That's the conclusion of a new study finding that women who eat at least five ounces of nuts a week have a 27 percent lower risk of developing Type II diabetes than those who rarely or never consume them. Those who eat peanut butter regularly also gain protection from the blood sugar disorder, according to the study, which appears in tomorrow's issue of the Journal of the American Medical Association.

Experts aren't clear why nuts guard against Type II diabetes, in which the body's cells become insensitive to the hormone insulin. However, nuts are high in healthful unsaturated fats and low in their harmful saturated cousins. They're also rich in antioxidants and other nutrients that may keep diabetes at bay.

"In our study, this [effect] was independent of known risk factors for Type II diabetes," said Dr. Rui Jiang, a postdoctoral fellow at the Harvard School of Public Health and lead author of the study. "It's unlikely that other factors generated this inverse association."

An estimated 17 million Americans have diabetes, and 16 million have the Type II form of the disease. Another 16 million people have "prediabetes," putting them at high risk of developing the full-blown illness.

Heart disease is the leading killer of diabetics, who face two to four times the normal risk of heart attacks as a result of their condition.

Even a 27 percent reduction in the chances of getting diabetes is "pretty substantial," said Dr. David Jenkins, a specialist in the condition at the University of Toronto who studies the health benefits of nuts. "All of us living in Western society are at risk."

Nuts are not just a diabetes wonder, added Jenkins, who receives research funding from the U.S. almond industry. They've also been shown to lower cholesterol and reduce heart disease.

The Harvard researchers studied 83,818 women participating in the Nurses' Health Study, a massive look at lifestyle and health begun in 1976.

In 1980, when the women were between 34 and 59 years old, 71 percent said they almost never or seldom at nuts. About a quarter ate them one to four times a week, and 5 percent ate at least five 1-ounce servings a week. Women who ate nuts frequently tended to weigh less than the others.

Over the next 16 years, 3,206 women developed Type II diabetes. Being overweight is linked to the disease. But even after taking into account pounds, smoking status, exercise habits, family history of diabetes, and other risk factors, the researchers found that higher nut intake cut the chances of having diabetes years later.

Women who ate the most nuts had a 27 percent lower risk of developing diabetes than those who ate the fewest. The risk for women who ate nuts less than once a week was 8 percent lower, and it fell 16 percent for those who ate nuts between one and four times a week. Women who ate five servings a week or more of peanut butter -- a substitute measure for peanut consumption -- had a 21 percent lower risk of diabetes than those who ate none or almost none of the spread.

Penny Kris-Etherton, a nutrition expert at Pennsylvania State University, called the results "very interesting" but said she couldn't explain them. "I'm not sure what it would be in nuts, other than a favorable fat profile," she said.

Total fat and unsaturated fat intake seem to help control insulin levels, Kris-Etherton said. And perhaps there are nutrients in nuts that also afford protection against blood sugar problems.

The effect may also be due, at least in part, to the fact that when people increase their nut intake and keep their calories steady, their consumption of carbohydrates falls. Carbohydrates raise blood sugar. "Maybe that is helping control a prediabetic state," Kris-Etherton said.

What To Do

For more on diabetes, visit the National Institute of Diabetes and Digestive and Kidney Diseases. For more on nuts, check out the Almond Board of California or the Peanut Institute.

SOURCES: Rui Jiang, M.D., postdoctoral fellow, Harvard School of Public Health, Boston; Penny Kris-Etherton, Ph.D., professor of nutrition, Pennsylvania State University, State College, Pa.; David Jenkins, M.D., Ph.D., professor of medicine and nutritional science, University of Toronto; Nov. 27, 2002, Journal of the American Medical Association
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