Eating higher amounts of vegetable fat or poly unsaturated fat may lower the risk of stroke, according to a new study.
The preliminary research also found that eating higher amounts of red meat, processed red meat and non-dairy animal fat increased the risk of stroke.
The study is the first of its kind to investigate the role fat derived from vegetable, dairy and non-dairy animal sources plays in stroke risk.
Fenglei Wang, Ph.D., lead author of the study and a postdoctoral fellow in the department of nutrition at Harvard’s T.H. Chan School of Public Health in Boston, said:
“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.”
The researchers analysed 27 years of follow-up from 117,136 participants in the Nurses’ Health Study (1984-2016) and Health Professionals Follow-up Study (1986-2016).
The participants were aged 50 on average, 63 per cent were female, 97 per cent were white and all were free of heart disease and cancer at enrolment.
The participants completed food frequency questionnaires at the beginning of the study and every four years during the duration of the study.
The questionnaires were used to calculate the amount, source and types of fat in their diet over the previous year.
The researchers then calculated an over-time average to reflect their long-term consumption.
Fat intake was divided into five groups.
The researchers found:
- During the study, 6,189 participants had strokes, including 2,967 ischemic strokes and 814 haemorrhagic strokes;
- Participants in the highest quantile of non-dairy animal fat intake were 16 per cent more likely than those in the lowest quantile to have a stroke;
- Dairy fat was not associated with an increased risk of stroke;
- Participants who ate the most vegetable fat and the most polyunsaturated fat were 12 per cent less likely to have a stroke than those who ate the least
- Those consuming one more total serving of red meat every day had an 8 per cent greater risk of stroke while those consuming one more serving of processed meat had a 12 per cent greater risk of stroke
Alice H. Lichtenstein, D.Sc., FAHA, the Stanley N. Gershoff professor of nutrition science and policy at Tufts University in Boston, said:
“Many processed meats are high in salt and saturated fat, and low in vegetable fat. Research shows that replacing processed meat with other protein sources, particularly plant sources, is associated with lower death rates.
“Key features of a heart-healthy diet pattern are to balance calorie intake with calorie needs to achieve and maintain a healthy weight, choose whole grains, lean and plant-based protein and a variety of fruits and vegetables; limit salt, sugar, animal fat, processed foods and alcohol; and apply this guidance regardless of where the food is prepared or consumed.”
The research has a number of limitations.
As the study is observational, the results cannot establish a cause-and-effect link between fat consumption and stroke risk.
Dietary intake was self-reported and may be inaccurate due to unreliable memory recall.
As the participants were overwhelmingly of white European ancestry, the findings cannot be generalised for the wider population.
