The new large scale study strengthens previously suggested links between trans-fat intake and the risk of ischemic stroke by reporting an increased risk of ischemic stroke in postmenopausal women who consume higher amounts of trans fatty acids – commonly found in baked goods, fried foods, and packaged products.
Writing in the Annals of Neurology, a research team from the University of North Carolina at Chapel Hill, USA, report that women with diets containing the highest amounts of trans fats were 39% more likely to have an ischemic stroke (clots in vessels supplying blood to the brain) than women who ate the least amount of trans fat.
"Our findings confirm that postmenopausal women with higher trans fat intake had an elevated risk of ischemic stroke," said Dr. Ka He He, an associate professor at the University of North Carolina, and senior researcher in the study.
Lead author Sirin Yaemsiri said the findings "highlight the importance of limiting the amount of dietary trans fat intake ... especially among postmenopausal women who have elevated risk of ischemic stroke."
Previous research has suggested that increased incidence of cardiovascular disease – one of the risk factors for stroke – is associated with trans fat consumption. However, the authors noted that previous studies on the topic have found no significant association between dietary fat intake and stroke. As a result, Dr He said the new results are contrary “to at least two other large studies of ischemic stroke.”
"However, ours was a larger study and included twice as many cases of ischemic stroke. Our unique study base of older women may have increased our ability to detect the association between trans fat intake and ischemic stroke," he said.
The new study analysed data from the Women's Health Initiative Observational Study – a prospective cohort study of 87,025 women between the ages 50 and 79 who are generally in good health.
At the time of enrolment participants were given a self-administered food frequency questionnaire and again three years later to assess their diet. The questionnaire asked about frequency of intake and portion size for 122 goods and food groups during a 3-month period and included questions related to fat consumption from meat, dairy, cooking, and reduced fat food items.
The team found 1,049 incident cases of ischemic stroke. They reported that women who had the highest trans fat intake (6.1 grams per day) had a 39% greater incidence of stroke compared to those who consumed less (2.2 grams per day).
After adjusting for clinical, lifestyle and dietary factors results showed trans fat intake was associated with a higher risk of lacunar infarction in particular.
The research team added that no significant association was found between total fat, other types of fat, or dietary cholesterol. However, aspirin use was found to reduce the association between trans fat intake and stroke.
Source: Annals of Neurology
Published online ahead of print, doi: 10.1002/ana.23555
“Trans fat, aspirin, and ischemic stroke in postmenopausal women”
Authors: S. Yaemsiri, S. Sen, L. Tinker, W. Rosamond, S. Wassertheil-Smoller, K. He