June 10, 2021 — More evidence suggests the long-standing belief that eating low amounts of saturated fats to ward off heart disease may not be entirely correct.
A new study that followed more than 4,800 people over 32 years shows that a plant-centered diet was more likely to be associated with a lower risk of future coronary heart disease and stroke, compared with focusing on fewer saturated fats alone.
“It’s true that low-saturated fat actually lowers LDL [or bad] cholesterol, but it cannot predict cardiovascular disease,” says lead study author Yuni Choi, PhD, postdoctoral researcher in the Division of Epidemiology and Community Health at the University of Minnesota. “Our research strongly supports the fact that plant-based diet patterns are good for cardiovascular health.”
To assess diet patterns of study participants, the researchers conducted three detailed diet history interviews over the follow-up period and then calculated scores for each using the A Priori Diet Quality Score (APDQS). Higher APDQS scores were associated with higher intake of nutritionally rich plant foods and less high-fat meats. While those who consumed less saturated fats and plant-centered diets had lower low-density lipoprotein (LDL) levels, or lower levels of “bad” cholesterol, only the latter diet was also associated with a lower risk of heart disease and stroke over the long term.
Choi said targeting just single nutrients such as total or saturated fat doesn’t consider those fats found in healthy plant-based foods with cardioprotective properties, such as avocado, extra virgin olive oil, walnuts, and dark chocolate. Based on study results, she recommends those conscious of heart health fill their plates with vegetables, fruits, whole grains, nuts, legumes and even a little coffee and tea, which were associated with a low risk of cardiovascular disease.
“More than 80% should be plant-sourced foods and then nonfried fish, poultry, and low-fat dairy in moderation,” she says.
“I think in focusing just on nutrients, we oversimplify the heart [health] diet hypothesis and miss the very important plant component,” says research team leader David Jacobs, PhD, professor, Division of Epidemiology and Community Health at the University of Minnesota. “If you tend to eat a plant-centered diet you will tend to eat less saturated fats because that’s just the way the plant kingdom works.”
Following a plant-centered diet is consistent with the American Heart Association’s (AHA) existing recommendations to minimize saturated fats and emphasize fruits, vegetables, whole grains, legumes, nuts, and seeds, says Linda Van Horn, PhD, professor, and chief of the Department of Preventive Medicine’s Nutrition Division at the Northwestern University Feinberg School of Medicine in Chicago, and a member of the AHA’s Nutrition Committee.
“There is no question that current intakes of plant-based carbohydrate, protein and fat are below what is recommended and moving in that direction would be a nutritious improvement,” she says, noting, however, that this doesn’t necessarily mean everyone needs to be on a vegetarian or vegan diet.
Given that plant-centered diets have been associated with lowering the risk of other diseases, the researchers are now looking to better understand how APDQS scores impact chronic conditions such obesity, diabetes, and kidney disease. They’ll also be researching how diet affects gut bacteria as they expect eating plant-based foods provides more fiber and promotes healthy microbiomes.
“I think that diet patterns provide a really solid base for the public and policy makers to think about what a healthy diet really is,” Jacobs says.