Different effects of palmitic and stearic acid-enriched diets on serum lipids and lipoproteins and plasma cholesteryl ester transfer protein activity in healthy young women.

The effects of palmitic and stearic acid-enriched diets on serum lipids, lipoproteins, apolipoproteins (apo) A-I and B, and plasma cholesteryl ester transfer protein (CETP) activity were examined in 12 healthy young women. Subjects followed the two experimental diets for 4 weeks according to a randomized crossover design. Both experimental diet periods were preceded by consumption of a baseline diet for 2 weeks. The diets provided 37% of total energy intake (E%) as fat, and differed only with respect to fatty acid composition. There was a substitution of 5E% of palmitic acid or stearic acid in the experimental diets for 5E% of monounsaturated fatty acids in the baseline diet. After the palmitic acid diet, serum total and high-density lipoprotein (HDL) cholesterol and apo A-I concentrations were higher (8%, P = .015, 9%, P = .040, and 11%,P = .011, respectively) and mean serum low-density lipoprotein (LDL) cholesterol concentration tended to be higher (8%, P = .077) as compared with values after the stearic acid diet. Plasma CETP activity increased in the palmitic acid diet as compared with the stearic acid diet (12%, P = .006). In conclusion, palmitic acid and stearic acid-enriched diets had different effects on serum lipids and lipoproteins and also on plasma CETP activity in young healthy women.

Lauric and palmitic acid-enriched diets have minimal impact on serum lipid and lipoprotein concentrations and glucose metabolism in healthy young women.

Fifteen healthy young women were fed diets enriched to 4% of energy with either palmitic acid (as palm oil) or lauric acid (as coconut oil). A randomized crossover study design was used so that subjects followed the two experimental diets for 4 wk, both preceded by consumption of a baseline diet for 2 wk. The experimental diets differed only with respect to the fatty acid composition: there was a substitution of 4% of energy intake with palmitic acid or lauric acid in the experimental diets for 4% of energy as monoenes in the baseline diet. There were no differences in the concentration of serum total or lipoprotein lipids, apolipoproteins A-I and B, and lipoprotein (a) or plasma cholesteryl ester transfer protein activity between the experimental diet periods. The VLDL cholesterol concentration (0.38 +/- 0.05 vs. 0.51 +/- 0.05 mmol/L, means +/- SEM, P = 0.01] and plasma cholesteryl ester transfer protein activity [78 +/- 5 vs. 88 +/- 6 mumol/(h.L), P = 0.007) were greater at the end of the lauric acid diet period than at the end of the preceding baseline diet period. No differences were found in glucose effectiveness, insulin sensitivity index or insulin secretion measured by the intravenous glucose tolerance test (Minimal Model method). In conclusion, in terms of serum lipids, lipoproteins, and glucose metabolism, palmitic acid was equal to lauric acid at 4% of total energy intake exchange, and both of these saturated fatty acids were comparable to a 4% of total energy intake exchange with monoenes in healthy young women.