When it comes to protein and heart health, blanket statements about animal or protein sources are too simplistic.
In 2010, Bernstein and colleagues reported differing associations between heart health and various protein-rich foods in the large Nurses’ Health Study (Bernstein, Sun et al. 2010). They observed that high protein red meat and high-fat dairy were associated with elevated risk of coronary heart disease, but that several other protein-rich foods were associated with lower risk, namely poultry, fish, low-fat dairy, and nuts. Eggs were neutral in this study.
A 2015 review in Advances in Nutrition examined the totality of evidence around protein food sources, specifically comparing whether plant-based protein foods differ from animal protein sources when it comes to heart disease risk factors (Richter, Skulas-Ray et al. 2015). Findings were summarized from observational and intervention studies.
Observational studies reveal that populations who consume large amounts of protein from plant foods tend to have lower blood pressure and blood cholesterol levels.
As with all observational studies, it is possible that these relationships may be related to other associated factors, like not smoking, having a lower body weight, and being more physically active.
Intervention studies show that the effects of plant protein and animal protein depend on the food matrix.
Typically, intervention studies can isolate the specific food from confounding factors. However, in this case, even intervention results remain confounded because each food source of protein provides a different composite of amino acids as well as non-protein compounds, which can affect heart disease risk. This includes different fatty acids, micronutrients and non-essential bioactive compounds.
When protein-rich foods are increased in the diet, other energy providing nutrients (i.e., fat or carbohydrate) are simultaneously reduced to maintain an energy neutral intervention.
Further, plant protein contains less protein per gram of food, so increased consumption of plant proteins is needed to achieve the same protein intake as meat protein.
For now, the authors concluded that:
“Evidence supports plant-based dietary patterns that emphasize protein-rich plant foods and include some animal-based sources of protein (e.g., fish/seafood, eggs, low-fat dairy, poultry, and lean meats) in place of refined carbohydrates and processed meats.”
Click here for an infographic on how to eat a plant-based diet or meet with your local dietitian.
Bernstein, A. M., Q. Sun, F. B. Hu, M. J. Stampfer, J. E. Manson and W. C. Willett (2010). “Major dietary protein sources and risk of coronary heart disease in women.” Circulation 122(9): 876-883.
Richter, C. K., A. C. Skulas-Ray, C. M. Champagne and P. M. Kris-Etherton (2015). “Plant Protein and Animal Proteins: Do They Differentially Affect Cardiovascular Disease Risk?” Adv Nutr 6(6): 712-728.
Elizabeth (Beth) J. Reverri, PhD, RD, LDN is a registered dietitian and postdoctoral researcher currently based in the greater Columbus, Ohio area. Beth was not financially compensated for this post. Opinions expressed are those of the author. For more information, click here.