Embracing legumes, nuts, and whole grains in place of meat may extend your lifespan.
How you satisfy your daily protein requirement may matter more than you think. According to the results of a Nature Communications study published in April, countries that consume more plant-based proteins have longer adult life expectancies than those that have higher intakes of animal-based protein.
The Context
An essential macronutrient, proteins play a role in the structure, function, and regulation of the body’s tissues and organs, including muscle. It helps your body build and repair cells and tissue and even supports processes like blood clotting, fluid balance, and immune response.
Not all proteins are created equal, though. In high quantities, animal-based protein is linked with chronic conditions such as cardiovascular disease, type 2 diabetes, and some cancers. There’s an environmental component, too. The production of animal-derived proteins (think: beef, sheep, chicken) emits significantly greater concentrations of greenhouse gasses than plant-based options, and intensive livestock production can harm biodiversity, degrade soil quality, and affect the nutrient balance of waterways due to manure and urine runoff.
Plant-based proteins — legumes and beans, nuts, whole grains, etc. — may have the opposite effect; they’re linked with a lower risk of some chronic diseases and overall mortality rates (potentially due to the difference in nutrient composition and bioactive compounds). And for every kilogram of CO2 equivalent created during production, some plant foods deliver up to 7.5 times more protein than meats, dairy, and eggs.
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The Details
To explore the potential effects of protein type on longevity, the researchers gathered 57 years of public data. This included information on demographics and food supply (e.g., the amount of food produced, levels of calories, proteins, and fats available for consumption) for 101 countries, many of which varied in the types of proteins predominantly consumed. Specifically, the stats reflected the average availability of food and nutrients nationally, not the average intake per person.
This data set was adjusted to account for differences in population size, wealth, and other factors between countries. Then, the researchers analyzed the stats as they related to survival rates for each age group and sex. Using an approximating model, the team was able to predict the effects of specific protein supplies on longevity.
The Key Findings
The team found that, in countries with greater availability of plant-based proteins, adults had longer life expectancies than in countries with greater availability of animal-derived options. In fact, individuals living in locations that had more supply of plant-based proteins and lower amounts of fat were more likely to live to 60 years old.
These findings are based on the availability of these macronutrients, not what people are actually consuming (among other limitations). But the researchers note that existing studies on individual diets have had similar results: There are long-term health and longevity benefits tied to plant-based protein in place of animal-derived options, including a reduced risk of type 2 diabetes, all-cause and dementia mortality, and cardiovascular disease.
Why? The high quantities of dietary fiber and whole grains often found in plant-based proteins may have something to do with it, according to the researchers. The latter has been linked to decreased risks of mortality from all causes, cardiovascular disease, and cancer.
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The Impact
The new findings add to the growing library of research showing that one’s eating habits may shape lifespan and healthspan. A recent National Institutes of Health study, for instance, found that eating an average of five servings of fruits and veggies a day was linked to a reduced risk of death from heart and respiratory diseases. And a 2022 Journal of Translational Medicine review found that total fiber, soluble fiber, and insoluble fiber intake was associated with lower risks of all-cause, cardiovascular, and cancer mortality. But unless greenhouse gas emissions are curbed — potentially through swapping animal proteins with plant ones and making other individual and systemic changes — that longer life could increasingly be impacted by the threats of climate change (extreme weather, worse air quality, you name it).
The Expert Insight
In a press release, lead investigator Alistair M. Senior, Ph.D., stated: "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."
The Caveat
While the results show a link between protein sources and longevity, the researchers note that the national data analyzed don’t account for the differing levels of plant- and animal-based protein access within each country, nor do they represent the actual eating habits of individuals. The study doesn’t factor in other lifestyle factors or separate the effects of different fat and carbohydrate types (think: saturated fat, fiber) on health. Not to mention, each person and their situation is different, and replacing animal proteins with plant-based versions won’t automatically mean they’ll be more likely to live to 60. Still, it's a simple swap could make a difference for your health in the long run.