The women ranged in age from 34 to 59 at the start of the prospective study period. All were enrolled in the Nurses' Health Study, which collected information on lifestyles and medical history from female nurses in 11 states. According to background information cited by the authors, an inverse relationship between fish intake and risk of stroke has been reported in several, but not all, prospective studies. But no prospective study has previously examined the relationship between intake of fish and n3 fatty acids and stroke risk, by stroke subtypes. According to The American Medical Association Encyclopedia of Medicine, stroke may be caused by any of three mechanisms.
Thrombosis is blockage by a thrombus, or clot, that has built up on the wall of a brain artery.
Thrombosis and embolism both lead to cessation or marked decrease of the blood supply to part of the brain, and thus to infarction, or tissue death. Compared with women who ate fish less than once per month, those with higher intakes of fish had a lower risk of total stroke. The authors examined the effect of fish and n3 fatty acid consumption on the risk of different types of stroke, and on women who regularly took aspirin. Aspirin itself can potentially lower stroke risk by reducing platelet aggregation. The study found no association between consumption of fish or n3 fatty acids and the risk of hemorrhagic stroke.