A Summary of the article “Association Between Plant and Animal Protein Intake and Overall and Cause-Specific Mortality”
The article is an Original Investigation published in JAMA Internal Medicine in 2020. Authored by Huang et al, the study aimed to examine the long-term associations between overall and cause-specific mortality and the intake of plant and animal protein in the US population. The authors sought to provide evidence that dietary modifications in protein choice may promote health and longevity.
Study Design and Participants
This research utilized a prospective cohort study design, analyzing data gathered over 16 years (1995 to 2011) from the US National Institutes of Health (NIH)–AARP Diet and Health Study. The final analytic cohort included 416,104 individuals, comprising 237,036 men and 179,068 women, with a total of 77,614 deaths observed during 6,009,748 person-years of observation.
Baseline dietary information on plant and animal protein intake was collected using a validated food frequency questionnaire. In this cohort, the median percentage of daily dietary protein intake was approximately 40% from plant sources and 60% from animal sources. Primary plant protein sources included bread, cereal, and pasta (45.8%), nuts (4.5%), and beans and legumes (8.0%). Primary animal protein sources were white meat (31.3%), red meat (30.6%), and dairy products (31.6%).
Key Findings on Plant Protein and Mortality
The study found a significant inverse association between greater dietary plant protein intake and reduced overall mortality in both sexes, independent of several other risk factors.
- For men, a 10 g/1000 kcal increment in plant protein intake was associated with a 12% lower risk of overall mortality (Hazard Ratio [HR], 0.88).
- For women, the same increment was associated with a 14% lower risk of overall mortality (HR, 0.86).
Plant protein intake was also inversely associated with mortality specifically from cardiovascular disease (CVD) and stroke in both men and women. For CVD mortality, the adjusted risk reduction per 10 g/1000 kcal increment was 12% in men and 17% in women. The association with overall mortality was largely similar across many population subgroups, including those stratified by smoking status and diabetes. Conversely, multivariable-adjusted animal protein intake was not significantly associated with mortality in men or women.
Substitution Effects
A crucial analysis examined the effect of replacing 3% of dietary energy from various animal protein sources with plant protein. This replacement of total animal protein with plant protein was associated with a 10% decreased risk of overall mortality and a lower risk of CVD mortality (11% lower risk in men, 12% lower risk in women).
The most prominent protective associations for overall mortality were seen when plant protein replaced:
- Egg protein: This substitution resulted in 24% lower overall mortality risk in men and 21% lower risk in women.
- Red meat protein: This substitution was associated with 13% lower overall mortality risk in men and 15% lower risk in women.
Substitution of plant protein for dairy protein also showed lower overall and CVD mortality. Notably, the mortality reduction was particularly strong when the plant protein came from bread, cereal, and pasta, replacing either egg or red meat protein.
Conclusion
The investigation concluded that higher plant protein intake is associated with small but significant reductions in the risk of overall and CVD mortality. The findings provide evidence that promoting dietary modifications favoring plant protein, especially as a replacement for egg and red meat protein, may influence health and longevity. The study collectively supports previous research highlighting the beneficial effects of plant-based protein choices on long-term health outcomes.
References
Huang, J., Liao, L. M., Weinstein, S. J., Sinha, R., Graubard, B. I., & Albanes, D. (2020). Association Between Plant and Animal Protein Intake and Overall and Cause-Specific Mortality. JAMA Internal Medicine, 180(9), 1173–1184. https://doi.org/10.1001/jamainternmed.2020.2790
This post is based on Open Access research and is for informational purposes only.
