A higher intake of vegetable fat, polyunsaturated fat, and vegetable oil was associated with a reduced risk of stroke, while a high intake of non-dairy animal fat, total red- and processed-meat, was associated with increased stroke risk.
In a study of more than 117,000 health professionals who were followed for 27 years, those whose diet was in the highest quintile for intake of vegetable fat had a 12% lower risk for stroke compared with those who consumed the least amount of vegetable fats.
Conversely, having the highest intake of animal fat from non-dairy sources was associated with a 16% increased risk of stroke.
The results were presented by Fenglei Wang, PhD, at the virtual American Heart Association (AHA) 2021 Scientific Sessions.
“Our findings support the Dietary Guidelines for Americans and dietary recommendations by AHA,"’ said Wang, a postdoctoral fellow in the Department of Nutrition at Harvard University’s TH Chan School of Public Health in Boston.
“The main sources of vegetable fat have a large overlap with polyunsaturated fat, like vegetable oils, nuts, walnuts, and peanut butter,” she said, adding that fish, especially fatty fish, is a main source of polyunsaturated fat and is recommended for cardiovascular health.
“We would recommend people reduce consumption of red and processed meat, minimise fatty parts of unprocessed meat if consumed, and replace lard or tallow (beef fat) with nontropical vegetable oils, such as olive oil, corn or soybean oils in cooking, to lower their stroke risk,” she said.
Although the results from this study of dietary fat were informative, she added, “There are other dietary factors (fruits, vegetables, salt, alcohol, et cetera), and lifestyle factors (physical activity, smoking, et cetera), associated with stroke risk and worthy of attention as well.”
“Many processed meats are high in salt and saturated fat, and low in vegetable fat,” said Alice Lichtenstein, an AHA spokesperson not involved with this study. “Research shows that replacing processed meat with other protein sources, particularly plant sources, is associated with lower death rates,” added Lichtenstein, the Stanley N. Gershoff professor of nutrition science and policy at Tufts University in Boston, and lead author of the AHA's 2021 scientific statement, Dietary Guidance to Improve Cardiovascular Health.
Study details
Dietary Fat Intake and the Risk of Stroke: Results from Two Prospective Cohort Studies
Fenglei Wang, Megu Y Baden, Kathryn M Rexrode, Frank B Hu
Published in AHA Journal Circulation on 8 November 2021
Abstract
Background
The association between specific types of fat intake and the risk of stroke remains inconclusive. Prospective data examining the relation of fat from different food sources to stroke risk are sparse. We aimed to investigate the association between total fat, various types of fat, and fat from different sources and the risk of stroke.
Methods: We followed 73,867 women (Nurses’ Health Study, 1984-2016) and 43,269 men (Health Professionals Follow-up Study, 1986-2016) free of cardiovascular disease and cancer at baseline. Dietary fat intake was collected by food-frequency questionnaires and categorised by sources and types. Cox proportional hazards models were used to assess the association between fat intake and stroke risk.
Results
During 3,168,151 person-years of follow-up, we documented 6,189 incident stroke events (including 2,967 ischemic and 814 hemorrhagic). A high intake of vegetable fat (HR comparing extreme quintiles=0.88; 95% CI: 0.81, 0.96; P-trend<0.001) or polyunsaturated fat (HR=0.88; 95% CI: 0.80, 0.96; P-trend=0.002) was associated with lower total stroke risk, whereas high non-dairy animal fat was associated with an increased risk (HR=1.16; 95% CI: 1.05, 1.29; P-trend<0.001). We observed similar associations for the ischemic stroke, but only the positive association of non-dairy animal fat was observed for the hemorrhagic stroke. For food groups contributing to fat intake, vegetable oil (HR per 1 serving/day=0.91; 95% CI: 0.84, 0.98) was associated with lower total stroke risk, while total red meat (HR=1.08; 95% CI: 1.02, 1.13) and processed red meat (HR=1.12; 95% CI: 1.03, 1.23) were associated with a higher risk. The association for vegetable oil was attenuated after adjusting for vegetable fat or polyunsaturated fat, while adjusting for non-dairy animal fat rendered total red meat and processed red meat nonsignificant.
Conclusions
A higher intake of vegetable fat, polyunsaturated fat, and vegetable oil was associated with a reduced risk of stroke, but a high intake of non-dairy animal fat, total red meat, and processed red meat was associated with increased stroke risk. These findings indicate the importance of considering the fat sources when examining the association between fat and stroke.
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