a1 Department of Human Biology, Maastricht University, PO Box 616, 6200 MD Maastricht, The Netherlands
In the present intervention study we compared the effects of α-linolenic acid with those of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on platelet aggregation in vitro and ex vivo in healthy non-institutionalized elderly subjects. We also compared the effects of α-linolenic acid on platelet aggregation in elderly subjects with those in younger volunteers. During a run-in period of 3 weeks all subjects (thirty-eight elderly (> 60 years) and twelve younger volunteers (< 35 years)) received a diet rich in oleic acid. For the next 6 weeks the elderly subjects received a diet rich in oleic acid (n 11), α-linolenic acid (n 14) (6·8 g/d) or EPA/DHA (n 13) (1·05 g EPA plus 0·55 g DHA). The younger subjects were given a diet rich in α-linolenic acid. The diets did not affect ADP- or collagen-induced platelet aggregation in vitro in either platelet-rich plasma or whole blood. The ex vivo platelet aggregation as measured with filtragometry was significantly decreased in the elderly group that received EPA/DHA compared with the α-linolenic acid (P = 0·006) and the oleic acid (P = 0·005) diet groups. Effects of α-linolenic acid were not age-dependent. Our results suggest that α-linolenic acid and EPA/DHA do not change in vitro platelet aggregation. Compared with oleic acid, EPA/DHA, but not α-linolenic acid, favourably affects ex vivo platelet aggregation in healthy elderly subjects.
(Received July 14 1998)
(Revised January 18 1999)
(Accepted April 05 1999)