Prospective study of fat and protein intake and risk of intraparenchymal hemorrhage in women

Background-Dietary animal fat and protein have been inversely associated wi th a risk of intraparenchymal hemorrhage in ecological studies. Methods and Results-In 1980, 85 764 women in the Nurses' Health Study cohor t, who were 34 to 59 years old and free of diagnosed cardiovascular disease and cancer, completed dietary questionnaires. From these questionnaires, w e calculated fat and protein intake. By 1994, after 1.16 million person-yea rs of follow-up, 690 incident strokes, including 74 intraparenchymal hemorr hages, had been documented. Multivariate-adjusted risk of intraparenchymal hemorrhage was higher among women in the lowest quintile of energy-adjusted saturated fat intake than at all higher levels of intake (relative risk [R R], 2.36; 95% CI, 1.10 to 5.09; P=0.03). For trans unsaturated fat, the cor responding RR was 2.50 (95% CI, 1.35 to 4.65; P=0.004). Animal protein inta ke was inversely associated with risk (RR in the highest versus lowest quin tiles, 0.32; 95% CI, 0.10 to 1.00; P=0.04). The excess risk associated with low saturated fat intake was observed primarily among women with a history of hypertension (RR, 3.66; 95% CI, 1.09 to 12.3; P=0.04), but such an inte raction was not seen for trans unsaturated fat or animal protein. These nut rients were not related to risk of other stroke subtypes. Dietary cholester ol and monounsaturated and polyunsaturated fat were not related to risk of any stroke subtype. Conclusions-Low intake of saturated fat and animal protein was associated w ith an increased risk of intraparenchymal hemorrhage, which may help to exp lain the high rate of this stroke subtype in Asian countries. The increased risk with low intake of saturated fat and trans unsaturated fat is compati ble with the reported association between low serum total cholesterol and r isk.