Stearic, oleic, and linoleic acids have comparable effects on markers of thrombotic tendency in healthy human subjects

Abstract

Because human studies concerning the effects of stearic acid on thrombotic tendency are inconsistent, we compared the effects of stearic acid with those of its unsaturated derivatives, oleic acid and linoleic acid. In this randomized, crossover study, 45 subjects (27 women and 18 men) consumed, in random order, 3 experimental diets, each for 5 wk. Diets contained ∼38% of energy as fat. Dietary compositions were the same except for 7% of energy from stearic, oleic, or linoleic acids. At the end of each period, ex vivo and in vitro platelet aggregation, and variables of coagulation, fibrinolysis, and hematology were evaluated. In men, ex vivo platelet aggregation time as measured by filtragometry (P = 0.036 for diet effects) was favorably prolonged during consumption of the linoleic acid diet compared with the stearic acid diet (P = 0.040), but there was no difference with consumption of the oleic acid diet (P = 0.198). In vitro platelet aggregation induced by collagen and ADP, and variables of coagulation (factor VII amidolytic activity and concentrations of fibrinogen and prothrombin fragment 1 and 2) and fibrinolysis [plasminogen activator inhibitor (PAI) activity and concentrations of tissue plasminogen activator (tPA)/PAI-1 complexes] did not differ among the 3 diets. The mean platelet volume of the subjects decreased during consumption of the stearic acid diet by 0.32 fL compared with the oleic acid diet (P < 0.001) and by 0.35 fL compared with the linoleic acid diet (P < 0.001). In conclusion, our results do not suggest that stearic acid is highly thrombogenic compared with oleic and linoleic acids. © 2005 American Society for Nutrition.