According to a long-term study with about 30 years of follow-up, eating a plant-centered diet during young adulthood is associated with a lower risk of heart disease in middle age. A separate study with a 15-year follow-up discovered that eating more plant-based foods that have been shown to lower cholesterol, known as the “Portfolio Diet,” is associated with a lower risk of cardiovascular disease in postmenopausal women.
Researchers discovered that when young adults and postmenopausal women ate more healthy plant foods, they had fewer heart attacks and were less likely to develop cardiovascular disease in two separate studies analyzing different measures of healthy plant food consumption.
According to the American Heart Association’s Diet and Lifestyle Recommendations, a healthy diet should include a variety of fruits and vegetables, whole grains, low-fat dairy products, skinless poultry and fish, nuts and legumes, and non-tropical vegetable oils. It also suggests limiting your intake of saturated fat, trans fat, sodium, red meat, sweets, and sugary drinks.
One study, “A Plant-Centered Diet and Risk of Incident Cardiovascular Disease During Young to Middle Adulthood,” looked at whether long-term consumption of a plant-centered diet, as well as a shift toward a plant-centered diet beginning in young adulthood, are associated with a lower risk of cardiovascular disease in midlife.
“Previously, research was focused on single nutrients or single foods, but there is little data about a plant-centered diet and the long-term risk of cardiovascular disease,” said Yuni Choi, Ph.D., lead author of the young adult study and a postdoctoral researcher at the University of Minnesota School of Public Health in Minneapolis.
Eating more nutritious, plant-based foods is heart-healthy at any age, according to two research studies published in the Journal of the American Heart Association, an open-access journal of the American Heart Association.
Choi and colleagues investigated the relationship between diet and the occurrence of heart disease in 4,946 adults enrolled in the Coronary Artery Risk Development in Young Adults (CARDIA) study. Participants in this study were between the ages of 18 and 30 at the time of enrollment (1985-1986) and were free of cardiovascular disease. Participants included 2,509 Black adults and 2,437 white adults (54.9 percent of whom were women overall), who were also classified according to their educational level. From 1987-1988 to 2015-16, participants had eight follow-up exams that included lab tests, physical measurements, medical histories, and an assessment of lifestyle factors. Unlike randomized controlled trials, participants were not instructed to eat certain things and were not told their scores on the diet measures, so the researchers could collect unbiased, long-term habitual diet data.
At years 0, 7, and 20 of the study, the quality of the participants’ diets were scored based on the A Priori Diet Quality Score (APDQS) composed of 46 food groups, following detailed diet history interviews. Based on their known association with cardiovascular disease, the food groups were classified as beneficial (such as fruits, vegetables, beans, nuts, and whole grains); adverse (such as fried potatoes, high-fat red meat, salty snacks, pastries, and soft drinks); and neutral (such as potatoes, refined grains, lean meats, and shellfish).
Participants who received higher scores ate a variety of beneficial foods, while people who had lower scores ate more adverse foods. Overall, higher values correspond to a nutritionally rich, plant-centered diet.
“In contrast to existing diet quality scores, which are typically based on a small number of food groups, APDQS is explicit in capturing overall diet quality using 46 individual food groups, describing the entire diet that the general population commonly consumes. Our scoring is very thorough, and it shares many similarities with diets such as the Dietary Guidelines for Americans Healthy Eating Index, the DASH diet, and the Mediterranean diet “Senior author of the study and Mayo Professor of Public Health in the division of epidemiology and community health at the University of Minnesota School of Public Health in Minneapolis, David E. Jacobs Jr., Ph.D.
Researchers found:
- During the 32-year study period, 289 of the participants developed cardiovascular disease (including heart attack, stroke, heart failure, heart-related chest pain or clogged arteries anywhere in the body).
- People who scored in the top 20% on the long-term diet quality score (meaning they ate the most nutritionally rich plant foods and fewer negatively rated animal products) were 52% less likely to develop cardiovascular disease after accounting for a variety of factors (including age, sex, race, average caloric consumption, education, parental history of heart disease, smoking and average physical activity).
- Furthermore, between years 7 and 20 of the study, when participants’ ages ranged from 25 to 50, those who improved their diet quality the most (eating more beneficial plant foods and fewer negatively rated animal products) were 61% less likely to develop subsequent cardiovascular disease than those whose diet quality declined the most during that time.
- Because there were few vegetarians among the participants, the study was unable to evaluate the potential benefits of a strict vegetarian diet that excludes all animal products, including meat, dairy, and eggs.
“A nutrient-dense, plant-based diet is beneficial to cardiovascular health. A plant-based diet does not have to be vegetarian “Choi stated. “People can select plant foods that are as natural as possible and are not overly processed. We believe that people can consume animal products in moderation on occasions, such as non-fried poultry, non-fried fish, eggs, and low-fat dairy.”
The study was supported by the National Institutes of Health’s National Heart, Lung, and Blood Institute, the University of Minnesota’s Healthy Food Healthy Lives Institute, and the MnDrive Global Food Ventures Professional Development Program.
In another study, “Relationship Between a Plant-Based Dietary Portfolio and Risk of Cardiovascular Disease: Findings from the Women’s Health Initiative (WHI) Prospective Cohort Study,” researchers at Brown University collaborated with WHI investigators led by Simin Liu, M.D., Ph.D., to determine whether diets that included a dietary portfolio of plant-based foods with U.S. Food and Drug Administration approval were associated with a lower risk of cardiovascular disease.
The “Portfolio Diet” includes nuts, plant protein from soy, beans, or tofu, viscous soluble fiber from oats, barley, okra, eggplant, oranges, apples, and berries, plant sterols from enriched foods, and monounsaturated fats found in olive and canola oil and avocadoes, as well as limiting saturated fats and dietary cholesterol.
Previously, two randomized trials found that eating foods from the Portfolio Diet at high target levels resulted in significant reductions in “bad” cholesterol or low-density lipoprotein cholesterol (LDL-C), more so than a traditional low-saturated-fat National Cholesterol and Education Program diet in one study and on par with taking a cholesterol-lowering statin medication in another.
The researchers wanted to see if postmenopausal women who followed the Portfolio Diet had fewer heart attacks. The study included 123,330 postmenopausal women from the Women’s Health Initiative, a long-term national study that looked at risk factors, prevention, and early detection of serious health conditions in women. The women in this study were 50-79 years old (average age 62) and did not have cardiovascular disease when they enrolled in the study between 1993 and 1998. The research group was followed up on until 2017. (average follow-up time of 15.3 years). Researchers used self-reported food-frequency questionnaires data to score each woman on adherence to the Portfolio Diet.
The researchers found:
- Those with the closest alignment were 11 percent less likely to develop any type of cardiovascular disease, 14 percent less likely to develop coronary heart disease, and 17 percent less likely to develop heart failure when compared to women who followed the Portfolio Diet less frequently.
- There was no link found between stricter adherence to the Portfolio Diet and the occurrence of stroke or atrial fibrillation.
“These findings represent a significant opportunity because there is still room for people to incorporate more cholesterol-lowering plant foods into their diets.” With increased adherence to the Portfolio dietary pattern, one would expect an association with fewer cardiovascular events, possibly as much as cholesterol-lowering medications. Even so, an 11 percent reduction is clinically significant and would satisfy anyone’s bare minimum for a benefit.
“The results show that the Portfolio Diet has heart-health benefits,” said John Sievenpiper, M.D., Ph.D., senior author of the study at St. Michael’s Hospital in Ontario, Canada, and associate professor of nutritional sciences and medicine at the University of Toronto. The researchers believe the findings highlight potential opportunities to reduce heart disease by encouraging people to consume more Portfolio Diet foods.
“We also found a dose-response in our study, which means you can start small, adding one component of the Portfolio Diet at a time, and gain more heart-health benefits as you add more components,” said Andrea J. Glenn, M.Sc., R.D., the study’s lead author and a doctoral student at St. Michael’s Hospital in Toronto and in nutritional sciences at the University of Toronto.
Although the study was observational and cannot directly establish a cause-and-effect relationship between diet and cardiovascular events, researchers believe that due to its sturdy design, it provides the most reliable estimate for the diet-heart relationship to date (included well-validated food frequency questionnaires administered at baseline and year three in a large population of highly dedicated participants). Nonetheless, the researchers state that these findings should be investigated further in additional populations of men or younger women.
