New research shows 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.
Study findings now available in Annals of Neurology, a journal published by Wiley-Blackwell on behalf of the American Neurological Association and Child Neurology Society, suggest aspirin use may moderate the stroke risk caused by a diet high in trans fats.
Ischemic stroke is a result of a blockage in an artery leading to the brain. According to the American Heart Association (AHA), 795,000 people have a new or recurrent stroke in the US each year. Reports from the AHA indicate that stroke is the fourth cause of death in the US, killing more than 137,000 Americans each year with 60% of those deaths in women.
Previous research suggests that increased incidence of cardiovascular disease—one of the risk factors for stroke—is associated with trans fat consumption. However, in other prior studies no significant association was found between dietary fat intake and stroke.
In the largest study of stroke in postmenopausal women to date, Dr Ka He and colleagues analysed data from the Women's Health Initiative Observational Study (WHI-OS)—a prospective cohort study of 87 025 women between the ages 50 and 79 who are generally in good health.
Higher the trans fat intake, higher the risk
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.
Results show 1,049 incident cases of ischemic stroke over 663 041 person-years of follow-up. Women who had the highest trans fat intake (6.1 grams/day) had a 39% greater incidence of stroke compared to those who consumed less (2.2 grams/day). Researchers found no significant associations between total fat, other types of fat, or dietary cholesterol. Aspirin use was shown to reduce the association between trans fat intake and stroke.
Additionally, researchers determined that of the ischemic stroke cases, there were 101 atherotherombotic, 234 cardioembolic and 269 lacunar infarctions, with another 445 unspecified cases that were not included in the subtype analysis. After adjusting for clinical, lifestyle and dietary factors results showed trans fat intake was associated with a higher risk of lacunar infarction.
"Our findings confirm that postmenopausal women with higher trans fat intake had an elevated risk of ischemic stroke, but aspirin use may reduce the adverse effects," concludes Dr He. "We recommend following a diet low in trans fat and adding an aspirin regimen to help women reduce their risk of stroke, specifically following the onset of menopause."
(EurekAlert, February 2012)