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 in the study, 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.
It accounts for 40 to 50 percent of strokes. It accounts for 30 to 35 percent of stroke cases. 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. Hemorrhages account for 20 to 25 percent of stroke cases. We observed a significant inverse association between fish intake and risk of stroke, primarily thrombotic stroke, after adjustment for cardiovascular risk factors and selected dietary variables, the authors write.