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For decades, many functional medicine clinicians have advocated that eating plant-based foods is heart-healthy at any age. Now two long-term observational studies have been added to the research that supports the positive association between plant-based foods and cardiovascular health.^1,2 In these two separate studies, which analyze different measures of healthy plant food consumption, researchers found that both young adults and postmenopausal women had fewer heart attacks and were less likely to develop cardiovascular disease (CVD) when they ate diets with plant-based foods.³

“Earlier research was focused on single nutrients or single foods, yet [prior to these studies,] there was little data about a plant-centered diet and the long-term risk of cardiovascular disease,” said Yuni Choi, PhD, lead author of the young adult study and a postdoctoral researcher in the division of epidemiology and community health at the University of Minnesota School of Public Health in Minneapolis.³

Plant-Centered Diet and Risk of Incident CVD During Young to Middle Adulthood

This study, published in the Journal of the American Heart Association, evaluated whether the long-term consumption of a plant-centered diet and a shift toward a plant-centered diet starting in young adulthood is associated with a lower risk of CVD in midlife.¹

The researchers examined diet and the occurrence of heart disease in 4,946 adults aged 18-30 who were free of CVD at the time of enrollment.¹ 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.³ After detailed diet history interviews, the quality of the participants’ diets was scored based on the A Priori Diet Quality Score, composed of 46 food groups, at years 0, 7, and 20 of the study. The food groups were classified into beneficial foods (such as fruits, vegetables, beans, nuts, and whole grains), adverse foods (such as fried potatoes, high-fat red meat, salty snacks, pastries, and soft drinks), and neutral foods (such as potatoes, refined grains, lean meats, and shellfish) based on their known association with CVD.¹

Participants who received higher scores ate a variety of beneficial foods while people who had lower scores ate more adverse foods.¹ Overall, higher values correspond to a nutritionally rich, plant-centered diet. The researchers found:

• During 32 years of follow-up, 289 of the participants developed CVD (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 adversely rated foods) were 52% less likely to develop CVD, after considering several factors (including age, sex, race, average caloric consumption, education, parental history of heart disease, smoking, and average physical activity).
• Between year 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 adversely rated foods) were 61% less likely to develop subsequent CVD in comparison to the participants whose diet quality declined the most during that time.¹

From a clinical perspective, these findings support a recommendation of eating primarily nutritionally rich plant foods while allowing for small amounts of animal products (low-fat dairy products, nonfried fish, and nonfried poultry) to prevent early CVD.¹ There were few vegetarians among the participants, so the study was not able to assess the possible benefits of a strict vegetarian or vegan diet, which excludes all animal products, including meat, dairy, and eggs.¹

Relationship Between a Plant-Based Dietary Portfolio and Risk of CVD

In this recent observational study, also published in the Journal of the American Heart Association, researchers evaluated whether or not diets that included a dietary portfolio of plant-based foods, known as the Portfolio Diet, were associated with fewer CVD events in a large group of postmenopausal women.²

The Portfolio Diet, a plant-based dietary pattern that was developed in the early 2000s to lower low-density lipoprotein cholesterol, is low in saturated fat and cholesterol with the addition of a “portfolio” of four cholesterol-lowering foods and nutrients: nuts, plant protein (soy and pulses), viscous fiber (oats, barley, psyllium, eggplant, okra, apples, oranges, and berries), and phytosterols (originally provided as enriched margarine).² An extension of the diet includes adding monounsaturated fats such as olive/canola oil or avocado.²

The current study analyzed whether 123,330 US postmenopausal women age 50-70 who followed the Portfolio Diet experienced fewer heart disease events.² Researchers used self-reported food-frequency questionnaires data to score each woman on adherence to the Portfolio Diet. They found:

• Compared to women who followed the Portfolio Diet less frequently, those with the closest alignment were 11% less likely to develop any type of cardiovascular disease, 14% less likely to develop coronary heart disease, and 17% less likely to develop heart failure.
• There was no association between following the Portfolio Diet more closely and the occurrence of stroke or atrial fibrillation.
• A dose-response effect was also found, meaning that patients could start small by adding one component of the Portfolio Diet at a time and gain more heart-health benefits as they add in more components.²

According to the study’s authors, given the increased interest in plant-based foods and diets around the world, as well as growing concerns related to ethical and environmental implications of diet, the Portfolio Diet warrants attention from healthcare professionals as another therapeutic dietary approach for cardiovascular disease risk reduction.² Although this study was observational and cannot establish a cause-and-effect relation between diet and cardiovascular events, the researchers believe it provides a reliable estimate due to its design (which included well-validated food frequency questionnaires administered at baseline and year three in a large population of highly dedicated participants).²

Previously, two randomized trials had demonstrated that reaching high target levels of food included in the Portfolio Diet resulted in significant lowering of low-density lipoprotein cholesterol, 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.^2,4-5

The benefits of the Portfolio Diet have been recognized in CVD and diabetes mellitus clinical practice guidelines internationally.² For further reading on this topic, please view the following related articles:

Pro-Inflammatory Diets and CVD Risk

Lifestyle Interventions to Modify Cardiovascular Disease Risk

The Hidden Hunger: Micronutrient Deficiencies

References

1. Choi Y, Larson N, Steffen LM, et al. Plant-centered diet and risk of incident cardiovascular disease during young to middle adulthood. J Am Heart Assoc. 2021;10(16):e020718. doi:1161/JAHA.120.020718
2. Glenn AJ, Lo K, Jenkins DJA, et al. Relationship between a plant-based dietary portfolio and risk of cardiovascular disease: findings from the Women’s Health Initiative Prospective Cohort Study. J Am Heart Assoc. 2021;10(16):e021515. doi:1161/JAHA.121.021515
3. American Heart Association. Eating more plant foods may lower heart disease risk in young adults, older women. Published August 4, 2021. Accessed September 28, 2021. https://newsroom.heart.org/news/eating-more-plant-foods-may-lower-heart-disease-risk-in-young-adults-older-women
4. Chiavaroli L, Nishi SK, Khan TA, et al. Portfolio dietary pattern and cardiovascular disease: a systematic review and meta-analysis of controlled trials. Prog Cardiovasc Dis. 2018;61(1):43-53. doi:1016/j.pcad.2018.05.004
5. Jenkins DJ, Kendall CW, Marchie A, et al. Effects of a dietary portfolio of cholesterol-lowering foods vs lovastatin on serum lipids and C-reactive protein. 2003;290(4):502-510. doi:10.1001/jama.290.4.502