Short-term diets enriched in stearic or palmitic acids do not alter plasma lipids, platelet aggregation or platelet activation status

Abstract

Objective: To determine whether healthy males who consumed increased amounts of dietary stearic acid compared with increased dietary palmitic acid through the consumption of commercially available foods, exhibited any changes in plasma lipids, platelet aggregation or platelet activation status. Design: A randomised cross-over dietary intervention. Subjects and interventions: Nine free-living healthy males consumed two experimental diets (stearic acid enriched, diet S, and palmitic acid enriched, diet P) for 3 weeks in a randomised cross-over design separated by a 3 week washout phase. The diets consisted of $ 30% of energy as fat (30% of which was derived from the treatment diets) providing $ 13 g=day as stearic acid and 17 g=day as palmitic acid on diet S and $ 7 g=day as stearic acid and 22 g=day as palmitic acid on diet P. The dietary ratio of stearic to palmitic acids was 0.76 on diet S compared with 0.31 on diet P. Blood samples were collected on days 0 and 21 of each dietary period. Results: LDL cholesterol levels and platelet aggregation response to the agonist ADP were significantly decreased (P < 0.025) in subjects on diet S compared with day 0. Apart from that, there were no significant changes in plasma lipids, platelet aggregation, mean platelet volume and platelet reactivity between diets. There were no significant changes in stearic or palmitic acid levels in plasma phospholipid or triacylglycerol. There was a significant difference in palmitic acid levels in platelet phospholipids between the two diets. Conclusions: Use of commonly available foods led to a 27% increase in stearic acid (diet S) and a 19% increase in palmitic acid (diet P), on diets S and P respectively, and no significant differences between the two diets in plasma lipoprotein concentrations, platelet aggregation or platelet activation status.

Plasma phospholipid and dietary fatty acids as predictors of type 2 diabetes: interpreting the role of linoleic acid

“…Although dietary intake of SFAs was not correlated with plasma phospholipid SFAs in the MCCS (6), our results suggest that reducing intakes of both palmitic and stearic acids could be beneficial. Short-term feeding studies show that SFA concentrations in platelet phospholipids can be changed by changing intakes of either palmitic or stearic acids (18,19). The KANWU study showed that plasma phospholipid SFA concentrations could be reduced by reducing SFA intake and increasing MUFA intake, with a corresponding improvement in insulin sensitivity (20).…”

Research advancements in palm oil nutrition

“…Neither HDL‐C nor plasma TAG differed significantly among the three study diets. Kelly et al (2002) concluded that there is no significant differences between the two diets enriched in C18:0 and C16:0 in plasma lipoprotein concentrations. Based on the food items, the diet enriched in C16:0 was a mixture of fats with triglyceride structures of POP and POo where palmitic acids were esterified at sn ‐1 or sn ‐3 positions which have relatively neutral effects on cholesterol levels.…”

Cocoa and Cardiovascular Health

“…46 Similarly, stearic acid, a saturated fat commonly found in chocolate, reduces mean platelet volume, an index of platelet activation, in humans. 75,76 …”