Dairy consumption and mortality after myocardial infarction: A prospective analysis in the Alpha Omega Cohort

Abstract

Background: Population-based studies generally show neutral associations between dairy consumption and ischemic heart disease (IHD) mortality, whereas weak inverse associations were found for cardiovascular disease (CVD) and stroke mortality. Whether dairy consumption affects long-term survival after myocardial infarction (MI) is unknown. Objectives: We studied types of dairy and long-term mortality risk in drug-treated post-MI patients. Methods: We included 4365 Dutch patients from the Alpha Omega Cohort aged 60-80 y (21% women) with an MI ≤10 y before enrollment. Dietary data were collected at baseline (2002-2006) using a 203-item FFQ and patients were followed for cause-specific mortality through December 2018. HRs of CVD, IHD, stroke, and all-cause mortality for types of dairy were obtained from Cox models, adjusting for age, sex, energy intake, physical activity, smoking, alcohol intake, diabetes, obesity, and dietary factors. Results: Most patients were Dutch, 24% were obese, 20% had diabetes, and 97% used cardiovascular medication. Median intakes were 39 g/d for plain yogurt, 88 g/d for total nonfermented milk, and 17 g/d for hard cheeses. Of the cohort, 10% consumed high-fat milk. During ∼12 y of follow-up (48,473 person-years) 2035 deaths occurred, including 903 from CVD, 558 from IHD, and 170 from stroke. Yogurt was linearly inversely associated with CVD mortality (HR: 0.96; 95% CI: 0.93, 0.99; per 25 g/d) and nonlinearly inversely associated with all-cause mortality. Milk was not associated with any of the outcomes (HRs: ∼1.0 per 100 g/d), except for a higher mortality risk in high-fat milk consumers (HR: 1.30; 95% CI: 1.13, 1.49). Other dairy groups were not associated with mortality risk. Conclusions: In Dutch post-MI patients, yogurt consumption was inversely associated with CVD mortality and all-cause mortality. Associations for milk and other dairy products were neutral or inconsistent. This trial was registered at clinicaltrials.gov as NCT03192410.