Total dietary fat, different types, and different food sources
Dr. Wang and colleagues investigated how total dietary fat, different types of fat, and fats from different foods were associated with incident stroke in 73,867 women in the 1984-2016 Nurses’ Health Study and 43,269 men who participated in the 1986-2016 Health Professionals Follow-up Study.
The participants had an average age of 50 years, 63% were women, and 97% were White. They replied to food-frequency questionnaires every 4 years.
Total red meat included beef, pork, or lamb (as a main dish or in sandwiches or mixed dishes) as well as processed red meats (such as bacon, sausage, bologna, hot dogs, and salami).
Animal fat sources included meat, beef tallow, lard, and full-fat dairy products, such as full-fat milk and cheese.
The median percentage of total daily calories from different sources of fat ranged from 10% to 20% for vegetable fat, 3% to 10% for dairy fat, and 7% to 17% for nondairy animal fat (for lowest to highest quintiles).
The median percentage of total daily calories from different types of fat ranged from 5% to 8% for polyunsaturated fat, 4% to 7% for n-6 polyunsaturated fat, 9% to 15% for monounsaturated fat, 8% to 14% for saturated fat, and 1% to 2% for trans fat.
During follow-up, there were 6,189 incident strokes, including 2,967 ischemic strokes and 814 hemorrhagic strokes.
The researchers found that intake in the highest quintile of vegetable fat was associated with a lower risk for total stroke, compared with the lowest quintile (hazard ratio, 0.88; 95% confidence interval, 0.81-0.96; P for trend < .001).
Similarly, the highest intake of polyunsaturated fat was also associated with lower total stroke (HR, 0.88; 95% CI, 0.80-0.96; P for trend = .002).
Highest intake of nondairy animal fat, however, was associated with an increased risk for total stroke (HR, 1.16; 95% CI, 1.05-1.29; P for trend < .001). They observed “similar associations” for ischemic stroke, but the only positive association for nondairy animal fat was with hemorrhagic stroke, the abstract notes.
The risk for stroke was lower by 9% per serving per day for vegetable oil but increased by 8% and 12%, respectively, per serving of total red meat or processed red meat.
The association for vegetable oil was attenuated after adjustment for vegetable fat or polyunsaturated fat, whereas adjustment for nondairy animal fat rendered the association for total red meat and processed red meat nonsignificant.
The study was funded by the National Heart, Lung, and Blood Institute of the National Institutes of Health. Dr. Wang has no relevant financial disclosures. Dr. Mente has received research funding from the Dairy Farmers of Canada and the National Dairy Council to analyze data on dairy consumption and health outcomes in the PURE study, which is funded by the Population Health Research Institute, Hamilton Health Sciences Research Institute, and more than 70 other sources (government and pharmaceutical).
A version of this article first appeared on Medscape.com.