High Trans Fat Intake Triples Heart Disease Risk

TUESDAY, March 27 (HealthDay News) -- Women who eat diets rich in unhealthy trans fats have three times the risk of heart disease as those with the lowest intake, a new study finds.

"This study just reinforces the idea that trans fat is bad -- worse than saturated fat -- and we need to make a concerted effort to reduce trans fats, including individuals, food manufacturers and policy-makers," said Dr. Frank Hu, senior author of the study and an associate professor of nutrition and epidemiology at the Harvard School of Public Health in Boston.

Results of Hu's study are expected to be published in the April 10 issue of the American Heart Association's journal,Circulation.

Trans fats, also called hydrogenated fats, are man-made compounds made from processed liquid oils. These harmful fats will raise bad cholesterol and could lower a person's good cholesterol levels. Because these fats are so thick and stiff, they can also clog up arteries and blood vessels, which can lead to heart attack or stroke.

Trans fats are commonly found in processed foods such as potato chips, cookies, doughnuts, cakes and many fast foods.

Previous research had already implicated dietary trans fat as a major player in the development of heart disease. However, past research had been done using self-reported dietary information. The current study includes an objective measure of trans fat intake -- trans fat levels in red blood cells. Hu explained that because red blood cells live for six months or more, trans fat levels in those cells are a good indicator of average trans fat intake.

The Harvard team examined blood samples collected from almost 33,000 women participating in the ongoing Nurse's Health Study. During the six-year study period, 166 women developed heart disease. The researchers then pulled information on 327 healthy women to serve as controls.

The women were grouped into four different quartiles based on the levels of trans fats in their blood.

The researchers found that women in the fourth quartile -- those with the highest trans fat levels -- had three times the risk of heart disease when compared to women with the lowest levels -- those in the lowest quartile. Women in the second and third quartile had a 60 percent greater risk of heart disease.

Hu and his colleagues also estimated the average daily trans fat intake from the trans fat blood levels. Women in the lowest quartile were estimated to have an average daily trans fat intake of 2.5 grams, while women in the highest quartile were estimated to take in 3.6 grams per day intake of trans fats. Hu stressed that these averages should be considered rough estimates.

The U.S. Food and Drug Administration (FDA) estimates that the average American diet contains about 5.8 grams of trans fat daily. The American Heart Association advises that trans fat should make up no more than one percent of your daily caloric intake.

Although no men were included in this study, Hu said he believes the findings are also applicable to men.