A new study just released by the Harvard T.H. Chan School of Public Health is reminding all of us that not all plant-based foods are equal in terms of health benefits.
Researchers report a diet characterized by healthy plant-based foods such as whole grains, leafy greens, and beans may reduce stroke risk in comparison to a diet filled with not-so-healthy plant-based foods like refined grains, added sugars, and potatoes. Sorry, French fry lovers.
In summation, they say a diet that emphasizes healthy plant-based foods and features minimal levels of lower-quality plant-based foods may lower one’s overall risk of stroke by up to 10%.
“Our findings have important public health implications, suggesting that future nutrition policies to lower stroke risk should take the quality of food into consideration,” says first study author Megu Baden, a postdoctoral fellow in the Department of Nutrition.
Tons of prior research has focused on the impact of plant-based foods and diets on subsequent risk of cardiovascular issues, diabetes, and other ailments. Surprisingly, however, studies focusing specifically on strokes have been few and far between.
So, in an attempt to rectify this oversight, the team at Harvard analyzed a big data set encompassing 209,508 men and women. All of those individuals had signed up for earlier long-term research projects decades ago and consented to have their health tracked for 25+ years. Each person also filled out periodic diet surveys every two to four years. All participants showed no signs of heart trouble or cancer at the beginning of the observation period.
Besides just the finding that a diet consisting of mostly healthy plant-based foods can reduce overall stroke risk by up to 10%, researchers also discovered that such a diet is linked to lower odds of suffering an ischemic stroke.
Ischemic stroke is the most common variety of stroke, occurring when blood flow to the brain is blocked. Notably and somewhat surprisingly, a healthy plant-based diet doesn’t seem to lower the risk of hemorrhagic stroke (bleeding or rupture in a brain artery).
Regarding vegetarianism, study authors found no evidence suggesting vegetarians also enjoy a reduced risk of stroke. To be fair, though, they admit there was a small number of strict vegetarians included in the dataset. This is speculation, but they theorize that finding may be due to many vegetarians including low-quality plant-based foods in their diets.
“Many individuals have been increasing the amount of plant-based components in their diet,” concludes study co-author Kathryn Rexrode, associate professor of medicine at Brigham and Women’s Hospital. “These results show that higher intake of healthy plant-based foods may help reduce long-term stroke risk, and that it is still important to pay attention to diet quality of plant-based diets.”
In the West, and especially in the United States, the dietary and food landscape is still very much dominated by super-sized options, ultra-processed foods, and an emphasis on sugar and red meat.
Subsequently, many dieters and health-conscious eaters may feel like they’re “eating healthy” just because they didn’t go for a cheeseburger or pizza for lunch. This research should serve as a reminder to all of us that just because it came out of the ground or was derived from a plant doesn’t necessarily mean it’s healthy.
The full study can be found here, published in Neurology.