Switching From Western Diet to Mediterranean Diet Could Add 10 Years to Life

We might one day be able to live to 150 thanks to some wicked new drugs or biotechnological enhancements. But until then, we have to rely on improving our lifespan the old-fashioned way: staying healthy and eating right.

It turns out diet might play a more outsized role than we thought. A new peer-reviewed study published in PLOS Medicine on Tuesday suggests that a young adult living in the U.S. could add more than 10 years to their expected lifespan simply by pivoting away from a typical Western diet and closer to a traditional Mediterranean diet. That means eating much less red and processed meat; and eating many more legumes, whole grains, and nuts.

“Food is fundamental for health, and global dietary risk factors are estimated to cause 11 million deaths and 255 million disability-adjusted life years annually,” Norwegian nutrition researcher and lead study author Lars Thore Fadnes told The Daily Beast. “Understanding the health potential of different food groups could enable people to make feasible and significant health gains.” Though previous studies have sought to characterize how diet is associated with lifespan, none have done so “with the same detail” as this new study, said Fadnes.

For the new study, Fadnes and his colleagues ran a broad analysis of data from the Global Burden of Diseases study—a comprehensive 2019 investigation that measured the trends and associations of hundreds of causes of deaths, diseases, and risk factors around the world. They used that data to build a model that identifies key associations between diet and lifespan.

Through the model, the team found that a typical 20-year-old American woman who switched to a more optimal diet would likely see her life expectancy increase by an average of 10.7 years; for American men, the average was 13 years. Even older individuals would experience gains in life expectancy by making the same dietary changes, though these would be a tad more modest (about 8 years for women aged 60; and 8.8 years for men aged 60).

According to the researchers, these gains are highly powered by an emphasis on legumes, which are known to have a beneficial “metabolic profile” and are high in fiber, proteins, carbohydrates, several B-vitamins, copper, magnesium, manganese, zinc, and phosphorous. “Legumes are practically free of saturated fat and cholesterol,” said Fadnes. Whole grains share many of these characteristics, as well. And nuts are known to be dense in nutrients, and rich in antioxidant and antimicrobial compounds.

According to Fadnes, these three foods are staples of diets in the so-called “blue zones” around the world that have unusually high rates of longevity, like Okinawa, Japan; Sardinia, Italy; the Nicoya Peninsula in Costa Rica; and Icaria, Greece.

Western diets, on the other hand, are energy-dense, have more saturated fats, and can produce many unhealthy compounds during preparations like frying and barbecuing—none of which is great for long life. The authors define a Western diet as one that’s heavy on red meat and processed meats, big on sugary drinks, contains about half the optimal amount of fruits and vegetables, and a relatively limited amount of whole grains and fish.

The biggest takeaway, obviously, is that people should move off of Western diets and adopt something similar to the Mediterranean diet. And they should especially start doing so at a young age (that won’t be an easy sell on most college campuses, but maybe someone can figure out a viral marketing campaign for Gen Z).

Fadnes and his colleagues have even turned their model into an online public tool called Food4HealthyLife. Users can plug in their information and get a calculation of their life expectancy and how dietary changes could help them gain more years. Fadnes cautions, however, that this shouldn’t be used to make individual forecasts about when you’ll die; rather, it should be a useful way to get a sense of how someone can improve their lifestyles.