Written by Joyce Smith, BS. Substituting intake of plant foods such as soy, nuts, and legumes for unprocessed, or processed red meat, and substituting whole grains and dairy products for total red meat, and eggs for processed red meat were all associated with a lower risk of coronary heart disease (CHD).
There is substantial evidence linking red meat , particularly processed red meat with an increased risk of death 1 and major chronic diseases 2-4 and coronary heart disease CHD 5. However, these risks are not prevalent in Asian populations where meat consumption is low or in countries with only slight increases in meat consumption 6. A failure in research to differentiate between processed and unprocessed red meats or to adequately compare red meat to other food energy sources 7 may be responsible for these inconsistencies. The following study by Al-Shaar et al 8 targeted these shortcomings through an improved study design and analysis.
The team, utilizing data from the Health Professionals Follow-up Study, explored the relationship between total, processed, and unprocessed red meat and CHD risk. They included, as well, the risk of CHD when substituting other protein sources for red meat. The 43,272 participating American men (average age 53) provided the team with detailed diet questionnaires in 1986 and every four years thereafter, up to 2016. Included in the study was information on participant medical history and lifestyle and any CHD events (fatal and non-fatal) that occurred over the 30-year period. During that time, 4,456 CHD events were documented of which 1,860 were fatal. At baseline, approximately 54% of participants were never smokers, 20% were hypertensive, 2% were diabetics, and 10% were hypercholesterolemic. Red meat eaters tended to be smokers, were diabetic, consumed alcohol, took aspirin and had` a history of CVD.
After taking account of other cardiovascular disease risk factors, the researchers found that the risk of CHD increased modestly for each daily serving of total, unprocessed, or processed red meat. For every one serving per day, total red meat was associated with a modest 12% higher risk of CHD, unprocessed red meat with an 11% higher risk, and processed red meat a 15% higher risk.
However, when comparing a plant protein-based diet to red meat, CVD risk was significantly decreased. Each serving of combined plant protein sources (which included soy, nuts, and legumes) decreased the risk of CHD for each type of red meat: a 13% lower risk for unprocessed red meat, 14% for total red meat, and 17% for processed red meat. Among men over the age of 65, the risk of CHD was even lower when a plant protein-based diet replaced processed red meat (18% versus 17%).
Substituting whole grains and dairy products (such as milk, cheese and yoghurt) for total red meat and eggs for processed red meat were also associated with lower CHD risk. This association was particularly strong among younger men, in whom the replacement of red meat with egg was associated with a 20% – 35% lower risk of CHD. Based on these findings, there may be benefits in replacing red meat with plant-based protein sources, whole grains, and dairy to reduce the risk of CHD. Further research is needed to confirm these findings and to determine whether women may also benefit from these substitutions.
Study limitations include the inability to prove causality, a potential misclassification bias, the existence of residual and unmeasured confounders, and the inability to generalize to other populations the predominantly non-Hispanic white male participants who had been selected from a cohort of health professionals of higher socioeconomic status.
Source: Al-Shaar, L., Satija, A., Wang, D. D., Rimm, E. B., Smith-Warner, S. A., Stampfer, M. J., … & Willett, W. C. (2020). Red meat intake and risk of coronary heart disease among US men: prospective cohort study. bmj, 371.
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Posted March 9, 2021.
Joyce Smith, BS, is a degreed laboratory technologist. She received her bachelor of arts with a major in Chemistry and a minor in Biology from the University of Saskatchewan and her internship through the University of Saskatchewan College of Medicine and the Royal University Hospital in Saskatoon, Saskatchewan. She currently resides in Bloomingdale, IL.
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- Al-Shaar L, Satija A, Wang DD, et al. Red meat intake and risk of coronary heart disease among US men: prospective cohort study. Bmj. 2020;371:m4141.
