Women who most closely adhere to a Mediterranean-style diet could be lowering their risk of stroke by up to 22 percent, according to 17-year results of a large-scale study out of the United Kingdom.
The research, published in the American Heart Association journal Stroke this week, assessed vascular outcomes associated with eating a Mediterranean diet—one high in fish, fruits, nuts, vegetables and cereals and lower in meats and dairy—in a pool of 23,232 white adults between 40 and 77 years old. Results were published after nearly two decades of study, making the trial one of the biggest and longest-running efforts to dissect the medical benefits of the diet.
“Conformity to a Mediterranean diet has been found to be beneficial for stroke prevention, although the results of previous studies have varied because of differences in study design, existing cardiovascular disease risk within populations and different methods of dietary assessment,” corresponding author Ailsa A. Welch, PhD, and colleagues wrote in the journal. “The beneficial effects of the [diet] are likely to be because of the overall effect or its constituent nutritional components on lowering blood pressure, lipids and inflammation and improving metabolic health.”
Welch and her team collected data from their participants through seven-day diet diaries, which they said are more accurate than the food-frequency questionnaires typically used in clinical research. With those diaries, patients tracked all food and drink they consumed over the course of a week.
After 17 years of observation, the researchers stratified study participants into four groups, ranked highest to lowest by how closely they followed a Mediterranean-style diet, and compared adherence to stroke risk. Adults who most closely emulated the diet saw a 17 percent reduced risk of onset of stroke, but women in particular recorded a 22 percent reduced risk. In women over 40, the diet seemed to be especially protective, regardless of menopausal status or hormone replacement therapy.
Men who most closely followed the diet, on the other hand, saw just a 6 percent decreased risk of stroke, the authors said.
“It is unclear why we found differences between women and men, but it could be that components of the diet may influence men differently than women,” Welch, a professor of nutritional epidemiology at the University of East Anglia in the U.K., said in a release. Her institution, alongside the Universities of Aberdeen and Cambridge, led the study.
“We are also aware that different subtypes of stroke may differ between genders. Our study was too small to test for this, but both possibilities deserve further study in the future.”
The team also found a 13 percent overall reduced risk of stroke in patients already at a high risk of CVD, regardless of how well they followed the diet. The authors said the association was likely driven mainly by women in that group, who showed a 20 percent reduced stroke risk.
Welch et al. said the study further supports AHA recommendations for a heart- and brain-healthy diet.
“Although the findings in our study were driven by the associations in women, they have implications for the general public and clinicians for prevention of stroke,” they wrote.
After graduating from Indiana University-Bloomington with a bachelor’s in journalism, Anicka joined TriMed’s Chicago team in 2017 covering cardiology. Close to her heart is long-form journalism, Pilot G-2 pens, dark chocolate and her dog Harper Lee.