Researchers from the Harvard T.H. Chan School of Public Health have recently published findings suggesting that a diet higher in plant-based proteins compared to animal proteins could significantly reduce the risk of cardiovascular diseases (CVD) and coronary heart disease (CHD).
The key takeaway from their study is that replacing red and processed meats with plant proteins can lead to better heart health.
They also observed that not just the quantity of protein consumed, but specifically the proportion of plant protein, plays a crucial role in maintaining heart health.
Study Overview
Despite global health guidelines advocating increased intake of plant-based proteins, the ideal proportion of plant to animal protein had been previously unestablished.
This study marks a pioneering effort to investigate that very ratio and its potential effects on cardiovascular well-being.
Current dietary habits in the United States usually reflect a plant-to-animal protein ratio of about 1:3.
However, the researchers suggest that a ratio of at least 1:2 could be more beneficial for preventing CVD, while a 1:1.3 ratio—favoring plant sources—may be optimal for reducing CHD risk, as stated by lead researcher Andrea Glenn, a former postdoctoral fellow at Harvard Chan.
Key Findings
The results will be available in the American Journal of Clinical Nutrition on December 2.
The research team conducted a thorough analysis of dietary and health data gathered over three decades from nearly 203,000 individuals participating in the Nurses’ Health Studies I and II, along with the Health Professionals’ Follow-up Study.
Every four years, these participants shared insights about their dietary habits, allowing the researchers to assess overall protein intake and distinguish between plant and animal protein sources.
During the study, 16,118 cases of CVD were recorded, including over 10,000 instances of CHD and more than 6,000 stroke occurrences.
After accounting for various lifestyle factors, health history, and demographics, the findings revealed that participants with a higher ratio of plant to animal protein faced a reduced risk of both CVD and CHD.
Specifically, those at the lower end of the spectrum, with an unfavorable ratio of roughly 1:4.2, faced much higher risks than those enjoying a better balance (about 1:1.3).
This group experienced a 19% lower risk of CVD and a 27% lower risk of CHD compared to their less fortunate counterparts.
Remarkably, individuals who consumed a higher overall protein intake—where 21% of their caloric intake came from protein—showed a 28% reduction in CVD risk and a 36% reduction in CHD risk, compared to those with lower protein consumption (16%).
Conclusions and Recommendations
Although the study did not establish a link between the protein ratio and stroke risk, the researchers noted that swapping out red and processed meats for plant-based sources, such as nuts, was associated with a lower stroke risk.
Scientists also explored the possibility of an upper limit to the benefits gained from plant protein.
Their findings suggested that while the protective effects for CVD seem to plateau around a 1:2 ratio, the risk of CHD continues to decline with higher ratios of plant proteins.
The researchers attribute these risk reductions primarily to the substitution of red and processed meats with a variety of plant-based protein sources—especially legumes and nuts—which promote positive changes in key cardiometabolic markers, such as blood pressure and inflammatory levels.
Additionally, plant proteins come packed with fiber, vitamins, minerals, and heart-healthy fats, enhancing their overall health benefits.
As senior author Frank Hu pointed out, transitioning to a diet with a greater emphasis on plant-based proteins is essential.
He urged individuals to decrease their consumption of red and processed meats while boosting their intake of legumes and nuts, emphasizing that these changes not only support personal health but also contribute positively to environmental sustainability.
The conclusions drawn from this study offer a starting point for understanding the ideal balance between plant and animal proteins in diets, although further research is needed to clarify these ratios and their link to stroke risk.
As ongoing studies unfold, they may provide more insight into the vital connection between dietary protein types and cardiovascular health.
Source: ScienceDaily