'Healthy' Diet May Increase Bad Cholesterol

Source: Yahoo

NEW YORK (Reuters Health) - There is a plethora of evidence suggesting that low-fat diets, particularly those rich in fruits and vegetables are "healthy." However, in a small study of women, a diet low in fat and high in fruits and vegetables caused an increase in the plasma levels of oxidized LDL cholesterol, the "bad" cholesterol.

This finding was unexpected, Dr. Marja-Leena Silaste from the University of Oulu in Finland and colleagues write in Arteriosclerosis, Thrombosis. and Vascular Biology: Journal of the American Heart Association (news - web sites).

To explore how alterations in diet affect LDL levels, researchers put 37 healthy women on two different diets. Both diets were low in total and saturated fat. One was low in vegetables and the other high in vegetables and fruits.

They discovered that blood levels of LDL increased by 27 percent in response to the low-fat, low-vegetable diet and 19 percent in response to the low-fat, high-vegetable diet. Both diets also produced small but significant decreases in HDL "good" cholesterol.

Silaste and colleagues think the "most likely reason" for the increase in LDL levels in response to the diets is the increase in a carrier protein called lipoprotein a.

This is certainly possible, Dr. Mohamad Navab and colleagues from the University of California, Los Angeles, write in an editorial, but there are other possibilities as well.

"Whatever the explanation, the findings by Silaste et al are sure to provide the basis for further exciting and potentially important studies," they write.

SOURCE: Arteriosclerosis, Thrombosis, and Vascular Biology, March 2004.