A young adult in the U.S. could add more than a decade to their life expectancy by changing their diet from a typical Western diet to an optimized diet that includes more legumes, vegetables, whole grains and nuts, and less red and processed meat, according to a new study.

Gains are predicted to be larger the earlier the dietary changes are initiated in life. For older people, the anticipated gains to life expectancy from such dietary changes would be smaller but still substantial. The message is clear. You’re never too young to start on a plant-based diet, and you’re never too old to benefit from it.

According to the study, young people starting out at age 20 could, on average, add 10 years to life expectancy for women and 13 years for men. Starting at age 60, it could add 8 years, on average, for women and 9 years, on average, for men. Even 80-year-old women and men could add 3 years, on average, to their life expectancy.

This should come as no surprise. The Journal of the American Medical Association says that diet is the number one risk factor for disease in the United States. Among the 10 leading causes of death (before COVID) are heart disease, cancer, stroke, diabetes, and chronic kidney disease, all of which a plant-based diet can help prevent and treat.

According to the study, an optimal diet had substantially higher intake than a typical western diet of whole grains, legumes, fruits, vegetables, and nuts.  Yet, many doctors treat nutrition as a side issue. Of course, they were offered little to no training in medical school.

Of course, we don’t say that nutrition is the only relevant factor in life expectancy. For instance cigarette smoking has a large impact, along with access to medical care. Nevertheless, the nutritional effect  on health is considerable and offers a wide ranging opportunity for increasing life expectancy.