Evidence around meat consumption in cardiovascular health and lipid management
Evidence from epidemiological studies suggests that higher consumption of red meat and processed meat is associated with a higher risk of developing cardiovascular disease (CVD).[i],[ii]
Effect of meat on lipids
Despite the findings from epidemiological studies, results from randomised controlled trials (RCTs) assessing the effect of red meat intake on CVD risk factors are inconsistent[iii],[iv]. A possible reason for this could be that the replacement food used in comparison interventions varies considerably in dietary quality and composition. This in turn could result in different CVD outcomes.
To address this, a meta-analysis of 36 randomised controlled trials, representing 1803 participants, compared diets with red meat with diets that replaced red meat with a variety of foods on various CVD risk factors[v]. Comparison diets were categorised into 1) high-quality plant protein sources (legumes, soya, nuts); 2) chicken/poultry/fish; 3) fish only; 4) poultry only; 5) mixed animal protein sources (including dairy); 6) carbohydrates (low-quality refined grains and simple sugars, such as white bread, pasta, rice, cookies/biscuits); 7) or usual diet.
Compared to all the comparison diets combined, consuming red meat had no effects on total cholesterol, LDL-C, HDL-C, apolipoproteins A1 and B, or blood pressure, but resulted in lesser decreases in triglyceride concentrations.
However, when each comparison diet was examined individually, substituting red meat with high-quality plant foods (i.e. soya, nuts, and legumes), but not with fish or low-quality carbohydrates, led to more favourable changes in total cholesterol and LDL-C concentrations. Compared to chicken or poultry diets, red meat showed no significant differential effects on lipid variables.
These findings emphasise the health-promoting effects of high-quality plant protein foods in comparison with red meat.
This study also highlights the importance of considering the comparison diet when investigating the relative effects of red meat on CVD risk factors.
[i] Micha R, Wallace SK, Mozaffarian D. Red and processed meat consumption and risk of incident coronary heart disease, stroke, and diabetes mellitus: a systematic review and meta-analysis. Circulation. 2010;121:2271– 2283. doi: 10.1161/CIRCULATIONAHA.109.924977
[ii] Victor W. Zhong; Linda Van Horn; Philip Greenland,; et al (2020) Associations of Processed Meat, Unprocessed Red Meat, Poultry, or Fish Intake With Incident Cardiovascular Disease and All-Cause Mortality. JAMA Intern Med. Published online. doi:10.1001/jamainternmed.2019.6969
[iii] Maki KC, Van Elswyk ME, Alexander DD, Rains TM, Sohn EL, McNeill S. A meta-analysis of randomized controlled trials that compare the lipid effects of beef versus poultry and/or fish consumption. J Clin Lipidol. 2012;6:352–361. doi:10.1016/j.jacl.2012.01.001.
[iv] O’Connor LE, Kim JE, Campbell WW. Total red meat intake of ≥0.5 servings/d does not negatively influence cardiovascular disease risk factors: a systemically searched meta-analysis of randomized controlled trials. Am J Clin Nutr. 2017;105:57–69. doi:10.3945/ajcn.116.142521.
[v] Marta Guasch-Ferré, Ambika Satija, et al (2019) Meta-Analysis of Randomized Controlled Trials of Red Meat Consumption in Comparison With Various Comparison Diets on Cardiovascular Risk Factors. Circulation;139:1828–1845 https://www.ahajournals.org/doi/pdf/10.1161/CIRCULATIONAHA.118.035225