Alternative proteins, from legumes to newer plant-based burgers, promise to protect both the planet and the heart. They have become a symbol of a new way of eating, considered more sustainable and, in theory, healthier. Although replacing meat with plant-based alternatives to reduce CV risk has gained broad acceptance, emerging evidence is raising questions about when, how, and for whom these options are truly beneficial.

The term “plant-based protein” (PBP) includes a wide range of foods because plant proteins differ substantially in composition and nutritional quality, which in turn influences their effects on cardiovascular (CV) health.

The rise of so-called PBP differs markedly from traditional plant protein sources, such as legumes. These newer products are designed to mimic the taste and texture of meat but are typically made from protein isolates, refined oils, and additives. From an industrial perspective, they have achieved considerable commercial success; however, evidence supporting their nutritional benefits remains limited.

In this context, the key issue is not simply whether a food is plant-based or animal-based, but rather its overall nutritional quality and degree of processing. 

Foods marketed as “healthy” include a broad range of products, and not all affect the body in the same way. Some studies point to clear benefits, others suggest more nuanced effects, and others raise concerns about potential risks, particularly when industrial processing is involved.

However, there is a broad scientific consensus that reducing consumption of meat, particularly processed meat, and replacing it with PBP sources is associated with lower CV risk. Large epidemiologic studies and systematic reviews published in recently support this conclusion.

CV Risk

One of the largest studies, published in The American Journal of Clinical Nutrition in 2024, followed more than 200,000 people over several decades and found that participants who consumed more PBP than animal protein had a 19% lower risk for CV disease and up to a 27% lower risk for coronary heart disease. According to the authors, the benefit depended not only on what was added to the diet but also on what was removed from it.

The biological mechanisms underlying this effect are also well documented. PBPs are often accompanied by fiber, antioxidants, and bioactive compounds while reducing the consumption of saturated fats and cholesterol. This combination promotes a healthier lipid profile, lowers low-density lipoprotein (LDL) cholesterol levels, improves vascular function, and helps reduce systemic inflammation, all central components of CV prevention.

This pattern also aligns with well-studied dietary models, such as the Mediterranean diet, in which legumes, nuts, and other plant foods play a central role. In this context, replacing less healthy animal protein sources with plant proteins appears to benefit the heart. However, that distinction, substitution itself, is where the debate begins.

Effect of Substitution

When studies concluded that PBP reduces CV risk, they rarely assessed these foods on their own. Instead, researchers have examined what happens when PBP replaces other foods in the diet, which makes interpretation more complex.

In large epidemiologic studies, health benefits appear when PBP replaces foods with clearly unfavorable nutritional profiles, such as processed meat or certain types of red meat. In other words, the observed effect reflects not only the addition of legumes, soy, or nuts, but also the removal of saturated fats, sodium, and compounds linked to meat processing.

Therefore, researchers are not measuring the “pure” effect of PBP alone but rather the effect of a broader dietary shift. In epidemiologic terms, these are substitution models that compare combinations of foods rather than individual ingredients. As a result, the same food may appear highly beneficial in one dietary context and show modest effects in another.

In other words, the benefit is relative rather than absolute and depends on a broader dietary context.

Protein Quality

An 8-week randomized trial conducted in Singapore in 2024 compared plant-based meat alternatives with meat products and found no significant cardiometabolic benefits. The plant-based alternatives had more fiber and potassium, but also more sodium. Researchers have concluded that nutritional quality is a key concern in this category of products. The study also found no significant improvements in LDL cholesterol or most other variables analyzed.

A 2025 systematic review conducted by Spanish researchers reported more favorable findings. Replacing meat with plant-based alternatives reduced the total cholesterol, LDL cholesterol by 12%, and body weight by 6%, 12%, and 1%, respectively. However, the authors emphasized the need for long-term studies.

Soy Evidence

Soy is one of the most extensively studied PBPs and has produced some of the most consistent findings on CV biomarkers. A 2024 meta-analysis including 63 clinical trials found modest reductions in systolic blood pressure, total cholesterol, and LDL cholesterol associated with soy protein supplementation. Another analysis published the same year, focused on isoflavones, also reported reductions in blood pressure with moderate-quality evidence.

Similarly, a 2024 review examining the effect of replacing cow’s milk with soy beverages found no worsening of the cardiometabolic profile and, in some cases, improvements in lipid levels, inflammation, and blood pressure.

Processing Concerns

A more controversial concern in this context is ultra-processed foods. A British cohort study published in The Lancet in 2024 found that plant-based foods that were not ultra-processed were associated with lower CV risk, whereas ultra-processed plant foods were associated with higher risk and mortality. This distinction challenges the assumption that all plant-based diets are automatically healthy.

It is also important to note that most studies assessed intermediate markers, such as cholesterol levels or blood pressure, rather than major clinical outcomes, such as myocardial infarction or stroke. This limitation restricts the ability to draw definitive conclusions about actual coronary risk.

Emerging Sources

While the debate continues regarding PBP, other alternative protein sources are also gaining attention despite limited evidence. One example is fungal-derived microproteins, which have shown promising effects on lipid profiles, particularly reductions in LDL cholesterol, possibly because of their structural fiber content. However, existing studies are limited and of short duration.

Seaweed also contains bioactive compounds, antioxidants, and omega-3 fatty acids with potential cardioprotective effects. However, most evidence was derived from experimental or preclinical studies, and concerns persist about iodine content and potential contaminants depending on the source.

Research on insects has mainly focused on food safety rather than on CV outcomes. Currently, there is insufficient evidence to determine their effects on heart health. Overall, these alternatives remain more promising concepts than the established clinical options.

What once appeared to be a straightforward solution, replacing meat with alternative proteins to improve heart health, is now more complex. Although the potential benefits are not in dispute, evidence increasingly suggests that outcomes depend on the type of food consumed, the degree of processing involved, and the overall dietary patterns.

This article was translated from El Médico Interactivo, part of the Medscape Professional Network.