Replacing Meat With Plants Could Add Years to Your Life, According to New Study

However, for children under five, higher levels of animal-based protein were linked to lower mortality rates.

A global study led by researchers at the University of Sydney has found that countries with higher consumption of plant-based proteins, such as chickpeas, tofu, and peas, tend to have longer adult life expectancies.

Published in Nature Communications, the research was conducted by Dr. Alistair Senior, PhD candidate Caitlin Andrews, and their team at the Charles Perkins Centre. They analyzed food supply and demographic data from 101 countries between 1961 and 2018. To ensure accuracy, the data was adjusted for factors like population size and national wealth. The goal was to determine whether the type of protein consumed influences longevity.

First author Caitlin Andrews said: “Our study suggests a mixed picture when it comes to comparing the health impacts of meat- versus plant-based protein at a population level.

“For the under-fives, a food system that supplies large amounts of animal-based proteins and fats – such as meat, eggs, and dairy – lowered rates of infant mortality. However, for adults, the reverse was true, where plant-based proteins increased overall life expectancy.”

Methodology

To understand the impact of plant- and animal-based protein diets on human longevity, the researchers analyzed publicly available data about the food supply of 101 countries across a 60-year period. The data included the amount of food produced per country, along with the levels of calories, proteins, and fats available for consumption.

The countries studied represented a range of food systems, including countries where the consumption of animal-based protein is higher, such as Australia, the US, Sweden, and Argentina, and areas where the consumption of plant-based foods is more prevalent such as Pakistan and Indonesia.

In order to compare the impact of different countries’ food supplies on life expectancy, the researchers corrected the data to take into account the differences in wealth and population size between countries. Having done this, they found that countries where the overall availability of plant-based proteins was higher, such as India, had relatively longer life expectancies than countries where animal-based proteins were more readily available, such as the US.

Animal-based proteins and health conditions

Eating high levels of animal-based protein, particularly processed meat, has long been linked to a range of chronic conditions such as cardiovascular disease, type 2 diabetes, and certain types of cancer.

Meanwhile, plant proteins – including legumes, nut,s and whole grains – are associated with a lower risk of chronic diseases and overall mortality rates, with studies suggesting that plant-based diets have contributed to the longevity in the most long-lived communities on the planet – Okinawa in Japan, Ikaria in Greece and Loma Linda in California.

Lead investigator Dr Senior said: “Protein is a crucial part of the human diet, but as eating habits change and developed countries look to decarbonize, where we get our protein from has come under greater scrutiny.

“The knowledge that plant-based protein is associated with a longer life is really important as we consider not only how our diets impact our own longevity, but the health of the planet.”

Reference: “Associations between national plant-based vs animal-based protein supplies and age-specific mortality in human populations” by Caitlin J. Andrews, David Raubenheimer, Stephen J. Simpson and Alistair M. Senior, 11 April 2025, Nature Communications.
DOI: 10.1038/s41467-025-58475-1

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