Good meat, bad meat, red meat, white meat

Getting sufficient dietary protein^[1] is essential to human health. However, controversies still exist regarding the health effects of consuming animal-based compared to plant-based proteins, as well as of consuming different types of animal-based proteins, such as red and white meats. According to the results from observational research^[2][3], the consumption of red meat is associated with a higher risk of cardiovascular disease (CVD), while the consumption of white meat is not.

While the reasons for the discrepancies between protein sources are not entirely clear, one proposed explanation is the tendency for red meats to contain more saturated fatty acids (SFAs), which are believed to contribute to the development of atherosclerosis^[4] through increasing^[5] low-density lipoprotein cholesterol (LDL-C). As you can see in Figure 1, this is a necessary component^[6][7] for plaque to form in the artery walls. Over time and through a complex series of cellular events^[4] involving several steps such as oxidation and an enzyme called Lp-PLA2, plaque inside the artery walls forms and grows, eventually resulting in atherosclerosis.

Indeed, randomized controlled trials^[8][9][10] comparing red meat to white meat as part of a low SFA diet have reported a lack of significant differences in lipoproteins between diets, which suggests that SFAs, rather than red meat per se, may be the culprit. However, most of the relevant research to date is observational in nature, while the available randomized controlled trials haven’t systematically evaluated the potential interaction between dietary protein source and SFA content, and their effects on atherogenic lipoprotein measures.

The study under review, called “APPROACH” (Animal and Plant Protein and Cardiovascular Health), aimed to evaluate the effects on atherogenic lipoprotein measures of diets in which the main source of protein was red meat compared to diets with similar total protein content delivered from white meat or plants, and to determine whether these effects were affected by the SFA content of the diets.

According to observational research, the consumption of red meat is associated with a higher risk of cardiovascular disease, while the consumption of white meat is not. The reason for this may be the higher content of saturated fats in red meat, which may contribute to the development of atherosclerosis by increasing low density lipoprotein cholesterol, or “bad cholesterol.” However, no studies to date have directly compared the lipoprotein effects of red meat with that of other food sources of protein in the context of both high and low saturated fat intake. The study under review compared the effects of high to low saturated fat diets with the main source of protein being either red meat, white meat, or plants on atherogenic lipoprotein measures.