Longevity Briefs: The Optimal Diet For Longevity Changes With Age

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Longevity briefs provides a short summary of novel research in biology, medicine, or biotechnology that caught the attention of our researchers in Oxford, due to its potential to improve our health, wellbeing, and longevity.

Why is this research important: We know that what we eat has a signficant impact on how long we live. Evidence from several decades ago suggests that globally, mortality in late life is higher in countries where a high ratio of fat to protein is supplied. Since then the data on global nutrient supply and mortality has improved, but the question of how consumption of major nutrient classes (carbs, protein and fat) affect mortality at different ages hasn’t been re-examined.

What did the researchers do: Researchers analysed 1879 life tables from 103 different countries. ‘Life tables’ follow a group of people born in the same year in the same population, and track their probability of living to a given age. These were analysed in relation to those populations’ supply of macronutrients (carbohydrates, protein and fat), while controlling for socioeconomic factors.

Key takeaway(s) from this research: A nutrient supply that is relatively high in fats and proteins (16 percent proteins and 40 to 45 percent of both fats and carbohydrates) was associated with reduced risk of death in early life. However, beyond the age of 55, consuming less fat in favour of carbs (11 percent proteins, 67 percent carbohydrates, and 22 percent fats) was associated with the lowest mortality.

Composition of total energy supply in terms of protein, carbohydrates, and fat (per-
centage), as well as total energy supply (kilocalories/capita/day) associated with the lowest probability mortality at each age (qx) for females in 2016. (B) As in A for
males.
Global associations between macronutrient supply and age-specific mortality.pdf. (2020). Retrieved 19 November 2020, from https://drive.google.com/file/d/1Nd5xqnhnvifFQO7Ldly7ZCriUajbZhSs/view

This study is limited by the fact that it measures nutritent supply, which is not perfectly representative of consumption, especially in wealthier countries where there is significant oversupply and food wastage. While the findings of this study might not translate directly to dietary advice, it suggests that future research into the relationship between supply and consumption could be valuable. The above results seem to suggest that ideal macronutrient intake changes with age, and that diets seeking to completely eliminate a particular macronutrient may be flawed.