ABSTRACT
The aim of this study was to investigate the effect of trans alpha-linolenic acid on platelet aggregation and blood haemostasis. A randomized, double blind dietary intervention trial was carried out with healthy male volunteers (n=88) in three European centers. After a 6-week washout period where subjects avoided foods containing all trans fats, subjects either continued for 6 weeks with a low trans diet or a diet where trans alpha-linolenic acid provided 0.6% of energy (supplied as oil, margarine, cheese, muffins, and biscuits). At the end of the washout period the intake of trans polyunsaturated fats was 58+/-115 mg/day; this increased in patients on the high trans diet by +1344+/-328 mg/day, compared with +10+/-67 mg/day in patients on the low trans diet (p<0.01). The change in trans alpha-linolenic acid in plasma cholesteryl esters was 0.26+/-0. 20 on the high trans and 0.00+/-0.07% of fatty acids on the low trans diet (p<0.001). No effect of the high trans diet was observed on platelet aggregation: collagen EC(50) high trans 157+/-100, low trans 152+/-90 ng/mL (NS); U44619 EC(50) high trans 81+/-61, low trans 59+/-27 nM (NS). The high trans diet did not affect platelet thromboxane production, fibrinogen levels, factor VII, activated factor VIIa, or plasminogen activator inhibitor activity. There were no center-specific differences in response to the high trans diet. A relatively high amount of trans alpha-linolenic acid for 6 weeks does not increase the risk of coronary heart disease by promoting platelet aggregation and blood coagulation.
