Blood pressure, dietary fats, and antioxidants.

We investigated the association of dietary fatty acids and antioxidants with blood pressure in 722 eastern Finnish men aged 54 y, examined in the Kuopio Ischaemic Heart Disease Risk Factor Study in 1984-86. Men with self-reported hypertension or cerebrovascular disease or under antihypertensive medication were excluded. Allowing for the major anthropometric, dietary, medical, and psychological determinants of blood pressure in multivariate regression analyses, both plasma ascorbic acid (p = 0.0008) and serum selenium (p = 0.0017) concentrations had a moderate, independent inverse association, estimated dietary intake of saturated fatty acids had a positive association (p = 0.013), and estimated dietary intake of linolenic acid had an inverse (p = 0.048) association with the mean resting blood pressure. The marked elevation of blood pressure at the lowest levels of plasma ascorbic acid and serum Se concentrations supports the hypothesis that antioxidants play a role in the etiology of hypertension.

Vitamin C deficiency and low linolenate intake associated with elevated blood pressure: the Kuopio Ischaemic Heart Disease Risk Factor Study.

We investigated the association of dietary fatty acids and plasma antioxidative vitamins with blood pressure in 722 eastern Finnish men aged 54 years, examined in the Kuopio Ischaemic Heart Disease Risk Factor Study in 1984-1986, who had no known hypertension nor any cerebrovascular disease. Allowing for the major anthropometric, dietary, medical and psychological determinants of blood pressure in a multivariate regression analysis, plasma ascorbic acid concentration had a moderate, independent inverse association (P less than 0.0001) and the estimated dietary intake of linolenic acid an inverse (P = 0.026) independent association with mean resting blood pressure. The marked elevation of blood pressure at the lowest levels of plasma vitamin C concentration supports the hypothesis of the role of antioxidants in the aetiology of hypertension.

Effect of omega-3 fatty acid supplementation on platelet aggregability and platelet produced thromboxane.

We investigated the sustained effect of 12-week supplementation of 2.880 g/day of omega-3 fatty acids on platelet aggregability, platelet produced thromboxane B2 concentration and serum fatty acid composition in a double-blind controlled trial in 44 healthy mildly overweight eastern Finnish men recruited from a representative population sample. The supplementation was discontinued seven days before the biochemical measurements. Body weight, alcohol consumption and dietary composition remained constant during the study. Even though the percentage of eicosapentaenoic acid (20:5 omega 3) in total serum lipids increased by 37% (p less than 0.01) and that of dihomo-gamma-linolenic acid (20:3 omega 6) decreased by 18% (p less than 0.01) more in the omega-3 supplemented than placebo group during supplementation, there were no significant differences in the changes in either the ADP induced platelet aggregation or in vitro platelet produced thromboxane B2 concentration between the groups. These data suggest that omega-3 fatty acids have no detectable sustained effect either on ADP induced platelet aggregation or on thromboxane produced by the platelets in vitro.

Inhibition of platelet aggregability by moderate-intensity physical exercise: a randomized clinical trial in overweight men.

It has been postulated that platelet function plays an important role in the initiation of atherosclerosis. Currently there are no definitive data on the longer-term effects of regular physical exercise on platelet function in humans. We assessed the influence of regular moderate-intensity physical exercise (brisk walking to slow jogging) on platelet aggregation in a population-based sample of middle-aged, overweight, mildly hypertensive men in eastern Finland. In this controlled study, we evaluated the net effect of exercise on platelet aggregation by studying changes in optical density and ATP release in platelet-rich plasma. A significant inhibition of secondary platelet aggregation from 27% to 36% was observed in the men taking regular exercise. These findings give new insight into the possible protective effects of exercise against the risk of ischemic heart disease.