Dietary intake of key nutrients and subarachnoid hemorrhage: A population-based case-control study in Australasia

Background: A healthy, balanced diet can prevent stroke, but little is known about dietary risk factors for subarachnoid hemorrhage (SAH). We aimed to determine the relationship between common dietary habits and risk of SAH. Methods: In a population-based, case-control study of SAH undertaken across 4 Australasian cities, a standardized questionnaire was used to obtain information on the frequency of consumption of 15 common food items and alcohol in incident cases (n = 383) and frequency-matched community controls (n = 473). Logistic regression models were used to estimate the independent effects of these dietary factors, after adjusting for conventional risk factors for SAH. Data are reported with odds ratios (OR) and 95% confidence intervals (CI). Results: The risk of SAH rose with increasing consumption of fat or skin on meat (p trend = 0.04), being highest in those with consumption >4 times weekly compared with no fat or skin on meat (adjusted OR 1.70, 95% CI 1.09-2.66), while use of skim or reduced-fat milk (p trend = 0.01) and fruit (p trend = 0.04) was associated with a reduced risk of SAH compared with rare use. Among people with a history of hypertension, frequently adding salt to food was associated with an increased risk of SAH, irrespective of whether they were (OR 2.58, 95% CI 1.29-5.13) or were not (OR 2.88, 95% CI 1.46-5.70) currently taking antihypertensive treatment. Conclusions: Frequent intake of fat appears to be associated with an increased risk of SAH, particularly in people with hypertension, while frequent use of skim or reduced-fat milk and fruit appears protective for SAH.