Combined effects of saturated fat and cholesterol intakes on serum lipids: Tehran Lipid and Glucose Study

This study investigated the combined effect of saturated fat and cholesterol intake on serum lipids among Tehranian adults.

In 443 subjects >or=18 y, dietary intake was assessed. Height and weight were measured and body mass index was calculated. Serum cholesterol, triacylglycerol, high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol levels were calculated. Cholesterol intakes >or=300 mg/d and saturated fat intakes >or=7% of total energy were defined as high intakes. Individuals were categorized into four groups based on cholesterol and saturated fat intakes.

Subjects' mean age was 40.1 +/- 14.6 y; those in whom cholesterol and saturated fat intake was normal had significantly less energy and fat intake than those with high cholesterol and saturated fat intakes (P < 0.01). Saturated fat intake had a significant effect on serum total and HDL-C levels. Subjects with a normal saturated fat intake had significantly less serum total and HDL-C than those who had high saturated fat intake (P < 0.01 and P < 0.05, respectively). Adjusting for age, sex, and body mass index, the main effect of cholesterol intake on HDL-C was significant (P = 0.05). Mean serum HDL-C was lower in subjects who had normal cholesterol intake than in those with high cholesterol intake.

These results show that cholesterol and saturated fat intakes have no combined effect on serum low-density lipoprotein cholesterol level, whereas cholesterol intake per se affects serum HDL-C level.