Positional distribution of fatty acids in dietary triglycerides: effects on fasting blood lipoprotein concentrations in humans.

We examined the effect of the positional distribution of fatty acids within dietary triglycerides on serum lipoproteins. Sixty subjects consumed two diets of equal fatty acid composition for 3 wk each. In the palm oil diet 82% of palmitic acid was attached to the outer two carbon atoms of glycerol, and 18% to the middle carbon. In the diet rich in enzymatically modified palm oil these figures were 35% and 65%, respectively. On the modified-fat diet, average lipoprotein concentrations showed nonsignificant (P > 0.13) increases of 0.06 mmol/L for total, 0.03 mmol/L for HDL, and 0.04 mmol/L for LDL cholesterol compared with palm oil. The small increases in total and LDL cholesterol were statistically significant in the men (n = 23) but not in the women (n = 37). The ratio of HDL to LDL cholesterol and serum triglyceride concentrations were unchanged. Thus, a large difference in dietary fatty acid configuration had little effect on lipoprotein concentrations in humans.