Health News

Low-Fat Diets Linked to Rare Form of Stroke in Women

Feb. 12, 2001 -- Skimping on dietary fat may increase the risk of a rare but deadly type of stroke. A new study suggests that women who have high blood pressure and who eat very little saturated fat may have as much as double the risk. But not everyone agrees. One expert is concerned about the message of this study and questions the validity of the researchers' approach.

The findings apply only to this select group of women. But the researchers say there is evidence from studies involving Japanese people who adhere to very strict low-fat diets that the risk of stroke is higher when saturated fat intake is low.

The message for some is, "you can go too far," in cutting the fat out of your diet, says Meir J. Stampfer, MD, a co-author of the study being reported in the Feb. 13 issue of Circulation: Journal of the American Heart Association.

For the study, researchers asked more than 85,000 female nurses between the ages of 34 and 59 to fill out questionnaires designed to determine how frequently they ate certain foods. The researchers then put the women into one of five categories based on their answers.

The analysis revealed that women in the lowest category -- those who ate the least amount of saturated fat per day -- had the highest rate of hemorrhagic stroke.

A hemorrhagic stroke is one that occurs when a small or medium-sized blood vessel leaks or bursts in the brain. The more common type of stroke, called an ischemic stroke, is one caused when cholesterol and other substances build up in the blood and block the flow of blood to the brain. Eating a diet low in fat is supposed to help prevent these strokes by keeping the arteries clear of fatty deposits so blood can flow freely.

The researchers say women who ate 20 grams or less of saturated fat per day had more than double the risk of hemorrhagic stroke compared with women who ate between 25 and 36 grams or more of saturated fat per day. But the increased risk was only significant for those with the highest blood pressure.

The most common sources of saturated fat are meat, milk, and milk products like cheese and ice cream.

Stampfer and colleagues say the results suggest that women who have high blood pressure and who eat very little meat and avoid other foods high in saturated fat should consider increasing their intake of these foods slightly.

"I would say these women should probably not be eating less than 20 grams a day [of saturated fat]," says Stampfer.

But not everyone agrees.

"I'm really concerned about the message [of this paper] that saturated fat isn't as bad as you think it is," Margo A. Denke, MD, tells WebMD. "I don't think that is the correct conclusion that people should make."