Bear evidence of omega-3's benefits.

Polar bears' eating habits make even the fat-soaked typical American diet look healthful. During winter, these chubby creatures eat only seal skin and blubber, leaving behind the lean portions of their catch for foxes and other animals. And in summer, when no seals are to be had, the bears simply go without eating.

Yet a new study indicates that polar bears have more healthful concentrations of artery-clogging cholesterol and fats in their blood during the winter - while eating nearly 100 percent fat - than during their summer fasts.

G. Edgar Folk Jr., an environmental physiologist at the University of Iowa in Iowa City, reports that fasting bears have nearly 25 percent higher total cholesterol concentrations and 50 percent higher triglycerides than their blubber-gobbling counterparts.

Folk attributes the difference to seal blubber's high concentrations of omega-3 fatty acids, which seals acquire from their diet of oily fish. Clinical trials in humans have shown that omega-3 fatty acids help reduce high concentrations of cholesterol in the blood, which can lead to heart disease.

Blubber-eating polar bears have 10 times more omega-3 fatty acid in their bloodstreams than fasting bears, says Folk. "Apparently, our fasting bears have higher blood [cholesterol and triglyceride] levels because of their very low levels of omega-3s," he concludes.

Folk suggests that the correlation might also hold true for people. A study of the causes of death among 8,000 Canadian Inuits (also known as Eskimos), published in the July Arctic Medical Research, shows that the incidence of heart disease in this indigenous population is one-fourth that among Canadians as a whole - despite the much higher fat content of the Inuit diet. Most of the fat eaten by Inuits comes from omega-3-rich fish or blubber.