[Influence of diet and life habits on platelet functions]

The measurement of platelet activation utilizes relatively complex and ill-standardized tests which vary from one laboratory to another. A long-term diet rich in saturated fatty acids is associated with platelet hyperaggregability which is suppressed after dietary changes, with an increased intake of polyunsaturated fatty acids, especially linoleic acid. However, the linoleic acid intake must not be too high. It is advised to maintain the polyunsaturated/saturated fatty acid ratio at 0.6 to 1 in subjects that are apparently in good health. Both 20:5 n-3 and 22:6 n-3, the main n-3 fatty acids of marine fish oils, inhibit platelet aggregation, but they do it weakly and only after a high intake. On the other hand, both emotional stress and tobacco smoking induce platelet activation, while a physical exercise of moderate intensity seems to be beneficial. Finally, there is no evidence that oral contraceptives with low oestrogen content induce platelet aggregation in women who have no other risk factor of coronary artery disease.