Meat is a staple source of protein and fat in many people’s diets. Previous studies suggest that higher consumption of red meat and processed meat is associated with higher risk of cardiovascular disease, cancer, and type 2 diabetes; however, these studies have been inconsistent.
Harvard researchers conducted a systematic search of the literature and found 36 studies which included 1,803 participants comparing red meat diets with other diets including diets with high-quality plant proteins (legumes, soy, nuts); chicken/poultry/fish; fish only; poultry only; mixed animal protein sources (including dairy); carbohydrates (low-quality refined grains such as white bread and pasta); or usual diet. The authors performed a meta-analysis, or a study of studies, to compare differences in various indicators of heart health including changes in cholesterol and blood pressure.
The authors found that when comparing a red meat diet to all other diets combined, red meat diets led to higher triglyceride concentrations; however, there were no other significant differences in total cholesterol, LDL, HDL, or blood pressure.
In contrast, when comparing red meat diets to diets with high-quality plant protein sources, the researchers found that increases in plant-based protein resulted in lower levels of total cholesterol and LDL – the “bad” cholesterol.
According to a press release from the Harvard School of Public Health,
“Asking ‘Is red meat good or bad?’ is useless,” said Meir Stampfer, professor of epidemiology and nutrition and senior author of the study. “It has to be ‘Compared to what?’ If you replace burgers with cookies or fries, you don’t get healthier. But if you replace red meat with healthy plant protein sources, like nuts and beans, you get a health benefit.”
Guasch-Ferré, M., Satija, A., Blondin, S. A., Janiszewski, M., Emlen, E., O’Connor, L. E., … & Stampfer, M. J. (2019). Meta-Analysis of Randomized Controlled Trials of Red Meat Consumption in Comparison With Various Comparison Diets on Cardiovascular Risk Factors. Circulation, 139(15), 1828-1845.
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