Abstract
Interpreting and utilizing the findings of nutritional research can be challenging to clinicians, policy makers, and even researchers. To make better decisions about diet, innovative methods that integrate best evidence are needed. We have developed a decision support model that predicts how dietary choices affect life expectancy (LE).
Generated Summary
This research article presents a modeling study that estimates the impact of food choices on life expectancy (LE). The study utilizes a life table methodology, drawing upon meta-analyses and data from the Global Burden of Disease study (2019), to assess how changes in the intake of various food groups affect LE. The primary goal is to provide insights into how dietary choices influence health outcomes, specifically focusing on an optimized diet and a feasibility approach diet. The study examines the potential LE gains associated with sustained changes in the consumption of fruits, vegetables, whole grains, refined grains, nuts, legumes, fish, eggs, milk/dairy, red meat, processed meat, and sugar-sweetened beverages. The methodology involves adjusting mortality rates based on dietary changes and calculating life years gained or lost. The study aims to offer a decision support model that can assist clinicians, policymakers, and individuals in understanding the health implications of dietary choices.
Key Findings & Statistics
- A sustained change from a typical Western diet to the optimal diet from age 20 years would increase LE by more than a decade for women from the United States (10.7 [95% UI 8.4 to 12.3] years) and men (13.0 [95% UI 9.4 to 14.3] years).
- The largest gains would be made by eating more legumes (females: 2.2 [95% UI 1.1 to 3.4]; males: 2.5 [95% UI 1.1 to 3.9]), whole grains (females: 2.0 [95% UI 1.3 to 2.7]; males: 2.3 [95% UI 1.6 to 3.0]), and nuts (females: 1.7 [95% UI 1.5 to 2.0]; males: 2.0 [95% UI 1.7 to 2.3]), and less red meat (females: 1.6 [95% UI 1.5 to 1.8]; males: 1.9 [95% UI 1.7 to 2.1]) and processed meat (females: 1.6 [95% UI 1.5 to 1.8]; males: 1.9 [95% UI 1.7 to 2.1]).
- Changing from a typical diet to the optimized diet at age 60 years would increase LE by 8.0 (95% UI 6.2 to 9.3) years for women and 8.8 (95% UI 6.8 to 10.0) years for men, and 80-year-olds would gain 3.4 years (95% UI females: 2.6 to 3.8/ males: 2.7 to 3.9).
- Change from typical to feasibility approach diet would increase LE by 6.2 (95% UI 3.5 to 8.1) years for 20-year-old women from the United States and 7.3 (95% UI 4.7 to 9.5) years for men.
- For the optimal diet and feasibility approach diet, the following intakes were used: 225 g and 137.5 g whole grains (fresh weight), 400 g and 325 g vegetables, 400 g and/ 300 g fruits, 25 g and 12.5 g nuts, 200 g and/ 100 g legumes, 200 g and 100 g fish, 25 g and 37.5 g eggs, 200 g and 250 g milk/dairy, 50 g and 100 g refined grains, 0 g and 50 g red meat, 0 g and 25 g processed meat, 50 g and 62.5 g white meat, 0 g and 250 g sugar-sweetened beverages, and 25 g and 25 g added plant oils.
- Table 1. LE for males and females at different ages from the United States, China, and Europe for different diets. Gain in LE when changing from a typical Western diet to a feasibility approach or optimized diet is also indicated.
- Increasing time to full effect from 10 years to 30 years, gains in LE were reduced by less than 1 year for 20-year-olds, but the gains for 60-year-olds and 80-year-olds were reduced by 35% to 71%.
- Health gains for 20-year-old females and males increased by 0.1 to 0.2 years, whereas gains increased by 0.5 to 0.8 years for 60-year-olds and 1.2 to 1.3 years for 80-year-olds.
Other Important Findings
- The study found that the largest gains in LE could be made by increasing consumption of legumes, whole grains, and nuts while decreasing red and processed meat intake.
- The Food4HealthyLife calculator enables the instant estimation of the effect on LE of a range of dietary changes.
- The study’s findings indicate that sustained dietary changes at any age can give substantial health benefits, with the greatest gains observed when changes are initiated earlier in life.
- Even the feasibility approach diet indicates increased LE by 7% or more for both sexes across age groups.
Limitations Noted in the Document
- The methodology provides population estimates under given assumptions and is not meant as individualized forecasting.
- The study acknowledges limitations including uncertainty in achieving full effects, variations in protective and risk factors, and the potential impact of future medical advancements and lifestyle changes.
- The study relies on meta-analyses, which present associations, and caution is advised when interpreting these.
- The quality of evidence varied across food groups, with some having high-quality evidence while others had moderate or low-quality evidence.
- The model does not account for the impact of past morbidity experienced due to disease or consider variations in risk factors or genetic vulnerability.
- The duration of dietary changes in the studies varied, which could affect the magnitude of the observed effects.
Conclusion
The study underscores the potential of dietary modifications to significantly impact life expectancy, with substantial gains predicted for people of all ages. The Food4HealthyLife calculator, as mentioned in the study, is proposed as a valuable tool for clinicians, policymakers, and individuals, aiming to enhance understanding of the health implications associated with diverse dietary choices. This approach can empower informed decisions at various levels, from personal dietary choices to broader public health strategies. The study emphasizes that optimizing dietary choices, particularly by increasing the intake of legumes, whole grains, and nuts while reducing red and processed meats, could substantially extend lifespan. The study’s results emphasize the importance of early dietary interventions, highlighting that the benefits of dietary changes are most pronounced when initiated earlier in life. The results suggest that even a feasibility approach, which represents more realistic dietary changes, can lead to significant gains in life expectancy. The study points out that the greatest benefits were associated with the most significant dietary changes. The researchers’ use of a life table methodology, combined with meta-analyses, provides a structured and comprehensive approach to estimating the impact of dietary choices on health outcomes. However, the study acknowledges several limitations, including the reliance on population-level data, and the time lag for full effects. Overall, the study’s findings reinforce the message that dietary choices have a profound impact on health and longevity, with the potential for substantial gains through informed and sustained dietary changes. The availability of the Food4HealthyLife calculator promotes practical application of the study’s findings, empowering both the public and healthcare professionals to make well-informed choices, and potentially extending lives.