New Study Finds Kind Of Fat Consumed Key To Stroke Risk, Not How Much

Fat has been associated with the risk for stroke, but are all fats equal in terms of the risks they pose? It may actually be the type of fat, not how much fat is consumed, that's important, a new study has found.

For the study, researchers conducted a 27-year follow-up of 117,136 participants. The American Heart Association (AHA) noted in a news release Monday that the study was done with two of the largest studies to look at the risk factors for chronic diseases, which are the Nurses' Health Study (1984-2016) and Health Professionals Follow-up Study (1986-2016).

The participants completed food frequency questionnaires at the beginning of every four years, which helped determine the "amount, source and type" of fats they consumed. During the study period, 6,189 participants had a stroke, nearly 3,000 of whom had an ischemic stroke while 814 had a hemorrhagic stroke.

The researchers found that those who ate more non-dairy animal fat were 16% more likely to have a stroke compared to those who were in the lowest quintile in the amount of fat intake.

"Those consuming one more serving of total red meat every day had an 8% higher risk of stroke, and those consuming one more serving of processed red meat had a 12% higher risk of stroke," the AHA noted.

Consumption of dairy fat in products such as cheese, milk and butter, however, was not associated with an increased risk for stroke. Interestingly, those who ate the most vegetable fat and polyunsaturated fats were even 12% less likely to have a stroke than those who ate the least.

"Our findings indicate the type of fat and different food sources of fat are more important than the total amount of dietary fat in the prevention of cardiovascular disease including stroke," study lead author, Fenglei Wang Ph.D. of Harvard's T.H. Chan School of Public Health in Boston, said as per the news release.

The study is said to be the first to "comprehensively analyze" stroke risk from consumption of fat from vegetable, dairy and non-dairy animal sources, AHA noted. It's not yet published in a peer-reviewed journal but it is set to be presented at the AHA's Scientific Sessions 2021 to be held from Nov. 13 to 15.

"If everyone could make small modifications, such as reducing red and processed meat intake, the implication for public health will be huge," Wang told NBC News.

Such modifications also include "minimizing" the fatty parts if red meat is consumed. Switching to non-tropical vegetable oils instead of beef fat or lard may also help.

"The average American diet relies on animal-based proteins, and the sooner we can shift that to more plant-based, the better off we'll be," Dr. Michael Miedema of the Minneapolis Heart Institute told NBC News. Miedema was not involved in the study.

Other means to reduce the risk of stroke include having regular physical activity and controlling alcohol consumption as well as tobacco use.