Nutty way to head off heart disease.

Nutty way to head off heart disease

Last summer, researchers at Loma Linda (Calif.) University reported epidemiological data suggesting that Seventh Day Adventists who rarely eat nuts suffer heart attacks and coronary deaths at roughly twice the rate of those who typically eat nuts five times a week (SN: 7/25/92, p.52). Now those researchers may have discovered why. By comparing the results of two four-week-long dietary intervention trials in 18 men, they found that eating moderate quantities of walnuts, without increasing total dietary fat and calories, "decreases serumcholesterol levels and favorably modifies the lipoprotein profile in normal [healthy] men."

Both experimental diets derived 30 percent of their calories from fat - a level recommended by the American Heart Association and 14 percent lower than the typical US. diet, which contains 35 percent fat. Writing in the March 4 New England Journal of Medicine, Joan Sabate and his co-workers reported that substituting walnuts for two-thirds of the fat in such a relatively low-fat diet further lowers cholesterol concentrations in the blood by more than 10 percent.

Since the walnut diet contained roughly three times the ratio of polyunsaturated to saturated fat found in the other low-fat diet, some drop in cholesterol should have been anticipated, says David Kritchevsky of the Wistar Institute in Philadelphia. More unexpected, he says, was the magnitude of the walnuts' apparent effect. Ordinarily the higher an individual's starting cholesterol, the more likely it is to respond to diet. And averaging just 182 milligrams of cholesterol per deciliter of blood, initial cholesterol readings in these men were fairly low.