Eating a more plant-based or Mediterranean-style diet could add up to ten years to your lifespan, a modeling study published February 8 in the journal PLOS Medicine suggests.
Using data from a 2019 study, researchers from the University of Bergen in Norway created an online tool called Food4HealthyLife to calculate life expectancy based on eating habits.
Their goal was to use existing evidence on the health effects of various food groups, and apply it to show how diet change might affect longevity, according to Dr. Lars T. Fadnes, lead author of the study and professor in the department of global public health at the University of Bergen. It's not meant for individual forecasting, but to estimate population health based on current assumptions, he said.
The team found that eating more plants and less processed food may add a decade to life expectancy, compared to a standard American diet full of added sugar, refined grains, and processed meat, according to the model.
"The optimized diet we present is similar to a traditional Mediterranean diet, but is also relatively close to plant-based diets," Fadnes told Insider.
In addition to a longer life, the evidence also suggests dietary improvements could boost mood, manage weight, and reduce risk of chronic illnesses, he said.
The biggest health improvements were linked to eating beans, whole grains, and nuts
Beans, the magical fruit, were found to be the most beneficial food for improving lifespan, according to the model, closely followed by whole grains and nuts. Fruits and veggies were also linked to a longer life, as were servings of fatty fish like salmon, sardines, and cod.
The model's predictions are supported by existing evidence and expert recommendations that the Mediterranean diet is one of the healthiest ways to eat.
The optimal diet, according to the model, also closely resembles eating habits in the Blue Zones, areas of the world where people live the longest, healthiest lives.
The plant foods are rich in fiber, a nutrient important for digestive health, heart health, and stable blood sugar. Nuts and fish provide healthy fats like omega-3 fatty acids, which can help manage inflammation and reduce blood pressure.
Cutting out sugar, refined grains, and meats also improves longevity, the model suggests
The model also helped predict which foods people should avoid to live longer, Fadnes said.
Processed meats like sausage, refined grains like pastries and white bread, and added sugars from products like soda and sweets, were all linked to a shorter life expectancy, according to the model.
Evidence suggests processed food is linked to higher risk of illnesses like cancer.
The model also suggests red meat is detrimental to health, although some evidence is mixed.
Even a few small changes might add years to your life
The model predicted that starting at age 20, switching from a standard American diet to one rich in beans, whole grains, fish, produce, and nuts could add 10.7 to 13 years to one's life.
But you can still benefit without completely overhauling your diet. Researchers found that a "feasible" healthy diet, with slightly more servings of healthy food and fewer unhealthy ones, could add six years to life expectancy.
While there was an "optimal" diet to maximize benefits, per the model, evidence showed a sliding scale of improvements, according to Fadnes.
"For some, it is feasible to eat more or less optimized, while for others, mainly small beneficial steps from an unhealthy starting point are possible," he said.
