The effect of dietary arachidonic acid on platelet function, platelet fatty acid composition, and blood coagulation in humans

Abstract

Arachidonic acid (AA) is the precursor of thromboxane and prostacyclin, two of the most active compounds related to platelet function. The effect of dietary AA on platelet function in humans is not understood although a previous study suggested dietary AA might have adverse physiological consequences on platelet function. Here normal healthy male volunteers (n = 10) were fed diets containing 1.7 g/d of AA for 50 d. The control diet contained 210 mg/d of AA. Platelet aggregation in the platelet-rich plasma was determined using ADP, collagen, and AA. No statistical differences could be detected between the aggregation before and after consuming the high-AA diet. The prothrombin time, partial thromboplastin time, and the antithrombin III levels in the subjects were determined also. There were no statistically significant differences in these three parameters when the values were compared before and after they consumed the high-AA diet. The in vivo bleeding times also did not show a significant difference before and after the subjects consumed the high-AA diet. Platelets exhibited only small changes in their AA content during the AA feeding period. The results from this study on blood clotting parameters and in vitro platelet aggregation suggest that adding 1.5 g/d of dietary AA for 50 d to a typical Western diet containing about 200 mg of AA produces no observable physiological changes in blood coagulation and thrombotic tendencies in healthy, adult males compared to the unsupplemented diet. Thus, moderate intakes of foods high in AA have few effects on blood coagulation, platelet function, or platelet fatty acid composition.

Omega-6 Fatty Acids and Risk for Cardiovascular Disease

“…18 When healthy volunteers were given Ϸ7 times the usual intake of AA (ie, 1.5 g/d) in a 7-week controlled feeding study, no effects on platelet aggregation, bleeding times, the balance of vasoactive metabolites, serum lipid levels, or immune response were observed. [5][6][7][8] Likewise, in a recent study from Japan, AA supplementation (840 mg/d for 4 weeks) had no effect on any metabolic parameter or platelet function. 19 Consistent with this, in observational studies, higher omega-6 PUFA consumption was associated with unaltered or lower levels of inflammatory markers.…”

High levels of dietary arachidonic acid triglyceride exhibit no subchronic toxicity in rats

“…Nelson and colleagues (23)(24)(25)(26)(27) have studied the effects of dietary supplementation of 4.5 g ARASCO ® /d in humans and found no change in platelet aggregation. Platelet aggregation was not measured in this study, but we found no changes in PT and APTT reflecting normal liver function in producing clotting factors.…”

Supplementation of Virgin Coconut Oil Compared with Copra Oil, Olive Oil and Sunflower Oil on Thrombotic Factors in Rats and In Vitro Platelet Aggregation

“…Dietary fat appears to influence both the atherosclerotic and thrombogenic components of coronary heart disease (CHD) (Miller, 1997;Hornstra, 1980). Previous studies have shown that fatty acids affect coagulation of blood (Leray, 2001;Tholstrup, 2003;Nelson et al, 1997), but the effects of individual fatty acids on haemostasis are still controversial (Hoak, 1997;Knapp, 1997), which depends on both the fatty acid chain length and the degree of saturation (McGregor et al, 1980;Hornstra and Starrenburg, 1973). There is evidence that dietary long-chain saturated fatty acids appear to increase platelet aggregation whereas intake of short and mediumchain fatty acids has been negatively correlated with platelet aggregation (Takachi et al, 2004).…”