Dietary protein and cardiovascular health

Bettina Mittendorfer, Ph.D.

Project Summary:

Cardiovascular diseases, including heart attack and stroke, are the leading causes of death. Diet is an important determinant of heart health and risk of death. In the proposed project, we will evaluate the effect of high protein intake on the factors involved that cause cardiovascular diseases. We hypothesize that eating too much protein increases the risk for heart attack and stroke.

The goal of LLF’s Longevity Research Program (LRP) at Washington University in St. Louis is to conduct research that supports LLF’s mission to identify factors that: i) assist in predicting mortality and morbidity of selected populations and ii) improve people’s health and longevity. Over the past decade, LRP, under the leadership of Drs. Luigi Fontana and John Holloszy, has focused on studying the health benefits of chronic calorie restriction. Studies supported by LRP found chronic calorie restriction protects against the cardiometabolic abnormalities associated with obesity. The results from studies conducted in animals and our own preliminary data suggest that part of the beneficial cardiometabolic effect of calorie restriction is due to the concomitant reduction in protein intake. The goal of this three-year LRP project is to evaluate the effect of dietary protein intake on cardiovascular health in people. This project will involve a new translational collaboration among several clinical and basic science investigators and will leverage the resources of a recently initiated NIH-funded (R01 DK121560; PI: Mittendorfer) randomized clinical trial that will evaluate the effect of high protein intake from different sources (animal and plant) on several key metabolic functions involved in the pathogenesis of type 2 diabetes. We hypothesize that high protein intake will increase the blood concentration of the proatherogenic secondary gut metabolite TMAO, which is derived from animal protein-rich foods, increase platelet aggregation, stimulate proatherogenic metabolic functions in blood monocytes, which are the precursors for atherosclerotic plaque, and impair vascular function (assessed as endothelial function and vascular compliance). We also hypothesize that the adverse effects of high protein intake will be greater with high protein intake from animal foods (e.g. meats and dairy), which are rich in the TMAO precursor carnitine, than plant foods. The results from the proposed studies will increase our understanding of the influence of dietary protein on healthy (disease-free) aging and could identify novel biomarkers of cardiometabolic health. This issue has become particularly important because high protein intake and consumption of protein-fortified foods is now a popular trend.

Progress Report

Co-Investigators at Washington University School of Medicine:

Babak Razani, MD, PhD – Department of Medicine (Cardiovascular Division)

Xiangyu Zhang, PhD – Department of Medicine (Cardiovascular Division)

George Schweitzer, PhD – Department of Medicine (Nutritional Science)


Collaborators at Washington University School of Medicine:

Kenneth Schechtman, PhD – Division of Biostatistics

Victor Davila, MD – Department of Medicine (Cardiovascular Division)

Brandon Kayser, PhD – Department of Medicine (Nutritional Science)