Plant-Based Protein Ratios: A Potential Game-Changer for Cardiovascular Health

A new study from the Harvard T.H. Chan School of Public Health underscores the potential of plant-based proteins in reducing cardiovascular risks. The research highlights that a higher ratio of plant protein to animal protein in the diet may significantly lower the risks of cardiovascular disease (CVD) and coronary heart disease (CHD).

“The average American eats a 1:3 plant-to-animal protein ratio,” said Lead author Andrea Glenn, PhD, a visiting scientist in the Department of Nutrition at Harvard Chan School during the study and now an assistant professor at New York University. “Our findings suggest a ratio of at least 1:2 is much more effective in preventing CVD. For CHD prevention, a ratio of 1:1.3 or higher should come from plants."

The study, published in the American Journal of Clinical Nutrition, is the first to analyze the ideal ratio of plant to animal protein for heart health. The findings are based on data spanning three decades from nearly 203,000 participants in the Nurses' Health Studies I and II and the Health Professionals' Follow-up Study. Participants reported dietary intake every four years, providing researchers a comprehensive look at how protein sources affect heart health.

Key results show that individuals consuming the highest plant-to-animal protein ratio (~1:1.3) experienced a 19 percent lower risk of CVD and a 27 percent lower risk of CHD compared to those with the lowest ratio (~1:4.2). Those with the highest overall protein intake (21 percent of daily energy) and a higher plant-to-animal protein ratio saw even greater benefits, including a 28 percent lower risk of CVD and a 36 percent lower risk of CHD.

Notably, stroke risk did not appear to be influenced by the plant-to-animal protein ratio. However, replacing red and processed meat with nuts and other plant sources correlated with a reduced risk of stroke, underscoring the cardioprotective role of plant proteins.

According to the researchers, these heart health benefits stem from replacing red and processed meats with plant proteins such as legumes, nuts, and whole grains. "Most of us need to begin shifting our diets toward plant-based proteins," said senior author Frank Hu, MD, PhD, the Fredrick J. Stare Professor of Nutrition and Epidemiology. "We can do so by cutting down on meat, especially red and processed meats, and eating more legumes and nuts. Such a dietary pattern is beneficial not just for human health but also the health of our planet."

Plant proteins often come bundled with dietary fiber, antioxidant vitamins, minerals, and healthy fats, which improve cardiometabolic risk factors such as blood lipids, blood pressure, and inflammation.

While the study emphasizes the advantages of increasing plant protein intake, it also raises questions about the optimal ratio for maximum benefits. The study noted that while the risk of CVD begins to plateau at a 1:2 ratio, the risk of CHD continues to decline at even higher ratios of plant-to-animal protein. According to Dr. Glen, further research is needed to confirm these findings and explore the relationship between protein intake and stroke risk.

For integrative practitioners, these findings reinforce the importance of dietary interventions in managing and preventing cardiovascular conditions. Encouraging patients to adopt a plant-forward diet by substituting red and processed meats with protein-rich plant foods like nuts, legumes, and whole grains could have profound health benefits.

As more research emerges, practitioners can provide patients with specific, actionable advice rooted in science. For now, the study suggests that recommending a gradual shift toward a 1:2 or higher plant-to-animal protein ratio is a heart-healthy strategy worth considering.