Abstract Body (Do not enter title and authors here): Background
The association between unprocessed red and processed meat intake and risk of coronary heart disease (CHD) remains controversial, particularly for unprocessed red meat. Moreover, few studies have evaluated the health effects of replacing these meats with different protein sources.
Methods
We examined associations between intakes of unprocessed red and processed (red and non-red) meat and CHD risk in a pooled analysis of 25 international prospective cohorts including 1,090,325 women and 673,694 men. Dietary intake was assessed at baseline within each cohort using a food frequency questionnaire. We calculated cohort- and sex-specific hazard ratios (HRs) and 95% confidence intervals (CIs) using proportional hazards regression and pooled estimates using random-effects models. We further conducted isocaloric substitution analyses by comparing coefficients for unprocessed red and processed meat with those of alternative animal- and plant-based protein sources.
Results
Over a maximum follow-up ranging from 7 to 30 years across cohorts, we documented 62,336 CHD death. After multivariable adjustment for body mass index, demographic, lifestyle, and medical factors, greater intakes of unprocessed red meat and processed meat were associated with a higher risk of fatal CHD, with stronger associations observed among women (p for heterogeneity due to sex <0.001). The HRs comparing extreme intake categories (≥125 vs. <10 g/d) of unprocessed red meat were 1.34 (95% CI: 1.15, 1.55; p for trend=0.003) for women and 1.06 (95% CI: 0.99, 1.17; p for trend=0.009) for men. For processed meat, the corresponding HRs (comparing ≥50 vs. <2 g/d) were 1.39 (95% CI: 1.22, 1.59; p for trend<0.001) for women and 1.13 (95% CI: 1.03, 1.25; p for trend<0.001) for men. Isocaloric replacement of unprocessed red meat or processed meat with nuts and seeds was associated with a lower fatal CHD risk in both sexes. Additionally, in women, the replacement of processed meat with soy products, poultry, seafood, or dairy products, while the replacement of unprocessed red meat with soy products and dairy products was associated with a lower risk.
Conclusions
These findings support global dietary recommendations to limit the intake of unprocessed red meat and processed meat for cardiovascular health, highlighting the benefits of replacing these meats with plant protein sources, particularly among women.