Surprising results from a small study of women found that a low-fat diet rich in fruits and vegetables caused an increase in the plasma levels of oxidized low-density lipoprotein (LDL; "bad") cholesterol. To determine how alterations in diet affect LDL levels, the researchers put 37 healthy women on 2 different diets, both low in total and saturated fat. One diet was low in vegetables, and the other was high in vegetables and fruits.
The results showed that blood levels of LDL increased by 27% in response to the low-fat, low-vegetable diet, compared with 19% in response to the low-fat, high-vegetable diet. Both diets produced small but significant decreases in high-density lipoprotein cholesterol. The researchers attributed the increase in LDL levels in response to the diets to an increase in lipoprotein a. (The findings were reported in the March 23, 2004, issue of Arteriosclerosis, Thrombosis, and Vascular Biology.)