Abstract
IMPORTANCE: Although the associations between processed meat intake and cardiovascular disease (CVD) and all-cause mortality have been established, the associations of unprocessed red meat, poultry, or fish consumption with CVD and all-cause mortality are still uncertain. OBJECTIVE: To identify the associations of processed meat, unprocessed red meat, poultry, or fish intake with incident CVD and all-cause mortality. DESIGN, SETTING, AND PARTICIPANTS: This cohort study analyzed individual-level data of adult participants in 6 prospective cohort studies in the United States. Baseline diet data from 1985 to 2002 were collected. Participants were followed up until August 31, 2016. Data analyses were performed from March 25, 2019, to November 17, 2019. EXPOSURES: Processed meat, unprocessed red meat, poultry, or fish intake as continuous variables. MAIN OUTCOMES AND MEASURES: Hazard ratio (HR) and 30-year absolute risk difference (ARD) for incident CVD (composite end point of coronary heart disease, stroke, heart failure, and CVD deaths) and all-cause mortality, based on each additional intake of 2 servings per week for monotonic associations or 2 vs 0 servings per week for nonmonotonic associations. RESULTS: Among the 29 682 participants (mean [SD] age at baseline, 53.7 [15.7] years; 13 168 [44.4%] men; and 9101 [30.7%] self-identified as non-white), 6963 incident CVD events and 8875 all-cause deaths were adjudicated during a median (interquartile range) follow-up of 19.0 (14.1-23.7) years. The associations of processed meat, unprocessed red meat, poultry, or fish intake with incident CVD and all-cause mortality were monotonic (P for nonlinearity ≥ .25), except for the nonmonotonic association between processed meat intake and incident CVD (P for nonlinearity = .006). Intake of processed meat (adjusted HR, 1.07 [95% CI, 1.04-1.11]; adjusted ARD, 1.74% [95% CI, 0.85%-2.63%]), unprocessed red meat (adjusted HR, 1.03 [95% CI, 1.01-1.06]; adjusted ARD, 0.62% [95% CI, 0.07%-1.16%]), or poultry (adjusted HR, 1.04 [95% CI, 1.01-1.06]; adjusted ARD, 1.03% [95% CI, 0.36%-1.70%]) was significantly associated with incident CVD. Fish intake was not significantly associated with incident CVD (adjusted HR, 1.00 [95% CI, 0.98-1.02]; adjusted ARD, 0.12% [95% CI, -0.40% to 0.65%]). Intake of processed meat (adjusted HR, 1.03 [95% CI, 1.02-1.05]; adjusted ARD, 0.90% [95% CI, 0.43%-1.38%]) or unprocessed red meat (adjusted HR, 1.03 [95% CI, 1.01-1.05]; adjusted ARD, 0.76% [95% CI, 0.19%-1.33%]) was significantly associated with all-cause mortality. Intake of poultry (adjusted HR, 0.99 [95% CI, 0.97-1.02]; adjusted ARD, -0.28% [95% CI, -1.00% to 0.44%]) or fish (adjusted HR, 0.99 [95% CI, 0.97-1.01]; adjusted ARD, -0.34% [95% CI, -0.88% to 0.20%]) was not significantly associated with all-cause mortality. CONCLUSIONS AND RELEVANCE: These findings suggest that, among US adults, higher intake of processed meat, unprocessed red meat, or poultry, but not fish, was significantly associated with a small increased risk of incident CVD, whereas higher intake of processed meat or unprocessed red meat, but not poultry or fish, was significantly associated with a small increased risk of all-cause mortality. These findings have important public health implications and should warrant further investigations.