Abstract
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. To study associations of dietary plant and animal fat intake with overall mortality and cardiovascular disease (CVD) mortality. 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. Specific food sources of dietary fats and other dietary information were collected at baseline, using a validated food frequency questionnaire. Hazard ratios (HRs) and 24-year adjusted absolute risk differences (ARDs) were estimated using multivariable-adjusted Cox proportional hazards regression. 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. 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.
Generated Summary
This research, published in JAMA Internal Medicine, presents a prospective cohort study examining the relationship between plant and animal fat intake from specific food sources and overall and cardiovascular disease (CVD) mortality. The study analyzed data from the NIH-AARP Diet and Health Study, a large prospective cohort conducted in the US from 1995 to 2019. The study involved 407,531 men and women, with data analyzed from February 2021 to May 2024. The primary objective was to study the associations of dietary plant and animal fat intake with overall and CVD mortality. The study collected dietary information using a validated food frequency questionnaire. Main outcomes were hazard ratios (HRs) and 24-year adjusted absolute risk differences (ARDs), estimated using multivariable-adjusted Cox proportional hazards regression. The investigation focused on evaluating how different sources of dietary fat—specifically from plant and animal origins—correlated with mortality outcomes, providing insights into the impact of dietary choices on long-term health. Statistical analyses included multivariable adjustments for various factors, including relevant food sources, to determine the independent effects of different fat sources on health outcomes.
Key Findings & Statistics
- The analysis included 407,531 men and women.
- During 8,107,711 person-years of follow-up, 185,111 deaths were ascertained, including 58,526 CVD deaths.
- 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.
- Median daily dietary fat intake from plant and animal sources was 24.7 g and 29.3 g, respectively.
- During up to 24 years of observation and 8,107,711 person-years, 185,111 deaths were recorded, including 58,526 from CVD (45,634 for heart disease and 10,877 for stroke).
- The HRs of CVD mortality were 0.93 (95% CI, 0.90-0.96), 0.90 (95% CI, 0.87-0.93), 0.87 (95% CI, 0.84-0.90), and 0.86 (95% CI, 0.82-0.89) for quintiles 2 through 5, compared with quintile 1 (P for trend < .001).
- Corresponding adjusted ARDs of CVD mortality comparing the highest vs the lowest quintile of intake was -0.73% (95% CI, -1.10% to -0.40%).
- In model 3, a higher intake of plant fat from grains or vegetable oils was associated with a reduced risk for overall mortality (quintile 5 vs 1: HR, 0.92 and adjusted ARD, -0.98% for fat from grains; HR, 0.88 and ARD, -1.40% for vegetable oils) and CVD mortality (HR, 0.86 and adjusted ARD, -0.71% for fat from grains; and HR, 0.85 and adjusted ARD, -0.71% for vegetable oils) (all P for trend < .001).
- A higher intake of plant fat from grains or vegetable oils was associated with a reduced risk for overall mortality (quintile 5 vs 1: HR, 0.92 and adjusted ARD, -0.98% for fat from grains; HR, 0.88 and ARD, -1.40% for vegetable oils) and CVD mortality (HR, 0.86 and adjusted ARD, -0.71% for fat from grains; and HR, 0.85 and adjusted ARD, -0.71% for vegetable oils) (all P for trend < .001).
- Higher intake of animal fat was associated with elevated risks for overall, CVD, and heart disease mortality (quintile 5 vs 1: fully adjusted HR, 1.16 [95% CI, 1.12-1.19], 1.14 [95% CI, 1.08-1.20], and 1.14 [95% CI, 1.07-1.21], respectively; all P for trend < .001).
Other Important Findings
- Greater plant fat intake was associated with lower overall and cardiovascular disease mortality, particularly fat from grains and vegetable oils, independent of other important mortality risk factors.
- 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.
- The inverse association of plant fat intake with overall mortality was significant among younger participants (<60 years at baseline) and those who consumed 1 to 3 alcoholic drinks per day.
- The positive animal fat-mortality association was greater for men, those aged 60 to 65 years, or with lower BMI (<25), or consuming 1 to 3 alcoholic drinks per day, and during the first 5 years of follow-up, for which all interactions were statistically significant.
- Substituting animal fat intake with plant fat was associated with a lower risk of mortality.
- Higher intakes of fat from dairy products and eggs were associated with increased risks of overall mortality (quintile 5 vs 1: HR, 1.09 and adjusted ARD, 0.86% for dairy fat; and HR, 1.13 and adjusted ARD, 1.40% for egg fat, respectively; P for trend < .001), CVD mortality (quintile 5 vs 1: HR, 1.07 and adjusted ARD, 0.24% for dairy fat; HR, 1.16 and adjusted ARD, 0.82% for egg fat, respectively; P for trend < .001), and heart disease mortality.
- Greater intake of fat from white meat was associated with a lower risk for overall mortality, but not CVD, heart disease, or stroke mortality.
- In model 2, a higher intake of red meat fat was associated with an increased risk for overall mortality, CVD mortality, and heart disease mortality.
- Higher intake of egg fat was associated with an elevated risk for stroke mortality, but no association was noted for intake of fat from red meat, white meat, or dairy.
Limitations Noted in the Document
- The study design was observational, so residual confounding cannot be ruled out.
- Measurement error in estimating dietary fat intake using a food frequency questionnaire.
- Dietary fat intake was calculated based on baseline data, which may not reflect dietary changes during follow-up.
- Findings may not generalize to other racial and ethnic populations due to the study’s participant demographics.
Conclusion
The findings of this prospective cohort study consistently demonstrate that a higher intake of plant fat, particularly fat from grains and vegetable oils, is associated with a lower risk for both overall and CVD mortality. This supports the idea that dietary choices significantly influence long-term health outcomes. The study underscores the importance of the source of dietary fats, as the consumption of animal-based fats from sources such as dairy and eggs, was associated with an elevated risk for both overall and CVD mortality. The results highlight that the substitution of animal fats with plant fats, such as those from grains or vegetable oils, may lead to a lower risk of mortality. The study suggests the benefits of adopting dietary guidelines that favor increased consumption of plant-based fats to improve overall health and reduce the risk of cardiovascular disease. The findings suggest that dietary guidelines could be refined to emphasize the importance of fat sources, advocating for increased consumption of plant-based fats, especially from grains and vegetable oils. This focus could potentially lead to improved public health outcomes and reduced mortality rates, providing a basis for practical dietary recommendations that emphasize the quality and origin of dietary fats.