Platelet aggregation, thromboxane production and thrombogenic ratio in postmenopausal women consuming high oleic acid-sunflower oil or palmolein.

BACKGROUND: Saturated fatty acids exert controversial effects on platelet aggregation and eicosanoid production. AIM: To investigate the effect of a dietary exchange between palmitic acid and oleic acid on both platelet aggregation and thromboxane B2 (TXB(2)) production, and on urine TXB(2), prostacyclin I2 (PGI(2) as 6-keto-protaglandin F(1)alpha), and the thrombogenic ratio (TXB(2)/6-keto-protaglandin F(1)alpha) in fourteen postmenopausal women. EXPERIMENTAL
DESIGN: Women were assigned to two consecutive 28-d dietary periods that were high in cholesterol (~400 mg/d) and fat (~46%en). In the first period all subjects followed an oleic acid-rich diet prepared with high oleic acidsunflower oil. This was followed by a second period rich in palmitic acid in the form of palmolein. DETERMINATIONS: Nutrient intakes, ADP-platelet aggregation, platelet TXB(2) production, urine TXB(2) and 6-keto-protaglandin F(1)alpha were measured during two dietary periods and the results obtained correlated to serum cholesterol, lipoproteincholesterol and peroxides, apolipoproteins and plasma tocopherol.
RESULTS: The palmolein diet led to an increase in the platelet aggregation rate (p < 0.05) and in the time for the maximal aggregation rate (p < 0.02). No significant differences were observed in platelet TXB(2) production. Palmolein increased urine TXB(2) in pg/mL (p < 0.05) and pg/min (p < 0.01), whereas the thrombogenic ratio (TXB(2)/6-keto-protaglandin F(1)alpha) did not change. Most changes were related to oil change, few to serum cholesterol level (< or > or = 6.2 mmol/L) or age (< or > or = 65 yr).
CONCLUSIONS: Palmolein diet activates platelet aggregation more in normocholesterolemics. Though palmolein increased thromboxane and tended to increase prostacyclin in urine in normo- and hypercholesterolemic women, the thrombogenic ratio did not change. These effects were related to the LDL and HDL concentration increases and to the absence of change in the total cholesterol/HDL-cholesterol ratio found following the dietary intervention.

RCT Entities:   Population Interventions Outcomes