Heart risks: this is nutty.

Physicians generally counsel people with an elevated risk of heart disease to eschew high-fat foods. Nuts, which derive 70 to 90 percent of their calories from fat, should rank high on that list of dietary no-no's, right?

Not necessarily A study of 31,200 Seventh Day Adventists suggests that people who nosh on nuts five times a week, compared with people who rarely eat them, may halve their risk of heart attacks and coronary death.

Most Seventh Day Adventists consume very little alcohol, meat, and caffeine, and health researchers suspected this might help explain why Adventists live longer than other Americans and suffer one-seventh as many heart attacks. To investigate these dietary factors, Gary E. Fraser and his colleagues at Loma Linda (Calif.) University mailed a detailed diet and lifestyle questionnaire to every Adventist over age 24 in California. His team then surveyed respondents annually, confirming heart attacks or coronary deaths through medical records.

After adjusting for potentially confounding variables such as weight, smoking, and hypertension, the researchers found that only nuts and, to a lesser extent, whole-wheat bread showed any strong link with coronary events. Both foods lowered risks, they report in the July Archives of Internal Medicine.

Adventists who ate nuts at least once a week lowered their heart risks by 25 percent. Munching nuts five or more times a week roughly doubled the apparent protection. A survey of randomly selected participants suggested that peanuts accounted for 32 percent of the nuts eaten, almonds for 29 percent, and walnuts for 16 percent.

"Has the magic bullet arrived? Is it the humble nut?" asks William P Castelli, director of the Framingham (Mass.) Heart Study In an editorial accompanying the research report, Castelli notes that "a preview of a feeding trial" by Fraser's team hints that nuts may exert their protection by altering blood lipids.