Improving food choices at an early age prolongs life by 10 years

Maintaining a change in diet from a typical to an optimized one from an early age can extend life expectancy (LE) by more than a decade, suggests a study.  Such gain drops significantly with delayed initiation of dietary changes, particularly when approaching the age of 80 years.

“An increase in the intake of legumes, whole grains, and nuts, and a reduction in the intake of red meat and processed meats, contributed most to these gains,” the researchers said. “Fruits and vegetables also have a positive health impact, but for these food groups, the intake in a typical Western diet is closer to the optimal intake than for the other food groups.”

This study extracted data and meta-analyses from the Global Burden of Disease study (2019). Based on this, the researchers used life table methodology to estimate how LE improved with sustained changes in intakes of fruits, vegetables, whole grains, refined grains, nuts, legumes, fish, eggs, milk/dairy, red meat, processed meat, and sugar-sweetened beverages. Estimates for an optimized diet and a feasibility approach diet were presented.

An optimal diet consisted of a substantially higher intake of legumes, fruits, vegetables, whole grains, fish, and included a handful of nuts, while reducing red and processed meats, sugar-sweetened beverages, and refined grains, than a typical diet. A feasibility approach diet was a midpoint between an optimal and a typical Western diet. [PLoS Med 2022;19:e1003889]

A sustained change from a typical Western to an optimized diet from age 20 years could result in an increase in LE by more than 10 years for women (10.7 years, 95 percent uncertainty interval [UI], 8.4‒12.3) and men (13.0 years, 95 percent UI, 9.4‒14.3) from the US.

The biggest LE gains were noted in those who consumed more legumes (females: 2.2, 95 percent UI, 1.1‒3.4; males: 2.5, 95 percent UI, 1.1‒3.9), whole grains (females: 2.0, 95 percent UI, 1.3‒2.7; males: 2.3, 95 percent UI, 1.6‒3.0), and nuts (females: 1.7, 95 percent UI, 1.5‒2.0; males: 2.0, 95 percent UI, 1.7‒2.3), and less red meat (females: 1.6, 95 percent UI, 1.5‒1.8; males: 1.9, 95 percent UI, 1.7‒2.1) and processed meat (females: 1.6, 95 percent UI, 1.5‒1.8; males: 1.9, 95 percent UI, 1.7‒2.1).

“Eating more legumes, whole grains, and nuts, and eating less red meat and processed meats were estimated to be the most effective ways to increase LE for individuals with a typical diet,” the researchers said. “This reflects a combination of the health effect for each food group combined with the difference between typical and optimal intakes.”

Previous meta-analyses also revealed robust positive health effects from intake of fruits, vegetables, and fish. However, the typical consumption for these food groups was closer to optimal intake than for other food groups, particularly for vegetables. [Int J Epidemiol 2017;46:1029-1056; Am J Clin Nutr 2017;105:1462-1473]

Earlier is better

At age 60 years, changing diet from a typical to an optimized one would extend LE by 8.0 years (95 percent UI, 6.2‒9.3) in women and 8.8 years (95 percent UI, 6.8‒10.0) in men, while doing so at age 80 years would result in a gain of 3.4 years (females: 95 percent UI, 2.6‒3.8; males: 95 percent UI, 2.7‒3.9).

On the other hand, changing from a typical to a feasibility approach diet could improve LE by 6.2 years (95 percent UI, 3.5‒8.2) for 20-year-old women and by 7.3 years (95 percent UI, 4.7‒9.5) in men.

“Gains are predicted to be larger the earlier the dietary changes are initiated in life,” the researchers said. “The Food4HealthyLife calculator that we provide online could be useful for clinicians, policy makers, and laypeople to understand the health impact of dietary choices.”

The overall quality of evidence, as assessed by NutriGrade, was moderate. The methodology provided population estimates under given assumptions and was not meant as individualized forecasting, according to the researchers.

Limitations of the current study included uncertainty for time to achieve full effects, the effect of eggs, white meat, and oils, individual variation in protective and risk factors, uncertainties for future development of medical treatments, and changes in lifestyle.