Plant and Animal Fat Intake and Overall and Cardiovascular Disease Mortality.

Importance: The impact of dietary fat intake on long-term human health has attracted substantial research interest, and the health effects of diverse dietary fats depend on available food sources. Yet there is a paucity of data elucidating the links between dietary fats from specific food sources and health.

Objective: To study associations of dietary plant and animal fat intake with overall mortality and cardiovascular disease (CVD) mortality.

Design, Setting, And Participants: This large prospective cohort study took place in the US from 1995 to 2019. The analysis of men and women was conducted in the National Institutes of Health-AARP Diet and Health Study. Data were analyzed from February 2021 to May 2024.

Exposures: Specific food sources of dietary fats and other dietary information were collected at baseline, using a validated food frequency questionnaire.

Main Outcomes And Measures: Hazard ratios (HRs) and 24-year adjusted absolute risk differences (ARDs) were estimated using multivariable-adjusted Cox proportional hazards regression.

Results: The analysis included 407 531 men and women (231 881 [56.9%] male; the mean [SD] age of the cohort was 61.2 [5.4] years). During 8 107 711 person-years of follow-up, 185 111 deaths were ascertained, including 58 526 CVD deaths. After multivariable adjustment (including adjustment for the relevant food sources), a greater intake of plant fat (HRs, 0.91 and 0.86; adjusted ARDs, -1.10% and -0.73%; P for trend < .001), particularly fat from grains (HRs, 0.92 and 0.86; adjusted ARDs, -0.98% and -0.71%; P for trend < .001) and vegetable oils (HRs, 0.88 and 0.85; adjusted ARDs, -1.40% and -0.71%; P for trend < .001), was associated with a lower risk for overall and CVD mortality, respectively, comparing the highest to the lowest quintile. In contrast, a higher intake of total animal fat (HRs, 1.16 and 1.14; adjusted ARDs, 0.78% and 0.32%; P for trend < .001), dairy fat (HRs, 1.09 and 1.07; adjusted ARDs, 0.86% and 0.24%; P for trend < .001), or egg fat (HRs, 1.13 and 1.16; adjusted ARDs, 1.40% and 0.82%; P for trend < .001) was associated with an increased risk for mortality for overall and CVD mortality, respectively, comparing the highest to the lowest quintile. Replacement of 5% energy from animal fat with 5% energy from plant fat, particularly fat from grains or vegetable oils, was associated with a lower risk for mortality: 4% to 24% reduction in overall mortality, and 5% to 30% reduction in CVD mortality.

Conclusions And Relevance: The findings from this prospective cohort study demonstrated consistent but small inverse associations between a higher intake of plant fat, particularly fat from grains and vegetable oils, and a lower risk for both overall and CVD mortality. A diet with a high intake of animal-based fat, including fat from dairy foods and eggs, was also shown to be associated with an elevated risk for both overall and CVD mortality.