A young adult in the U.S. could lengthen their lifespan by more than 10 years by shifting away from a typical Western diet and toward a traditional Mediterranean diet, a new study has found.
"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."
Previous studies have attempted to characterize the relationship between nutrition and lifespan, but none have done so "with the same detail" as this new study, according to Fadnes.
More plant-based foods (legumes), whole grains, and nuts, as well as less red and processed meat, have the greatest overall impact. Fruits and vegetables are also beneficial to one's health, although most individuals who eat a conventional Western diet already consume them in large quantities.
Fish is also on the list of healthy foods, although sugar-sweetened beverages (sodas) and foods made from refined [white] grains, such as white bread, are not.
Depending on how many healthy dietary "switches" are made and maintained, as well as the amounts eaten, a 20-year-old man in the U.S. may live an additional 13 years, and a 20-year-old woman an additional 11 years.
This figure decreases with age, but switching from a conventional diet to an optimal diet at the age of 60 might extend life expectancy by 8 years for women and 9 years for men, and an 80-year-old female could gain more than three years with healthier dietary choices.
Until now, research in this area has focused on the health advantages of certain food groups or diet patterns, rather than the health effects of other diet changes. According to the researchers, the statistical "modelling" approach adopted in this work bridges that gap.
The most important message is that people should abandon Western diets in favor of something more akin to the Mediterranean diet. They should begin doing so at an early age, if possible.
Fadnes and his colleagues have even created an online public tool called Food4HealthyLife based on their methodology. Users can enter their information and receive a computation of their life expectancy as well as how dietary adjustments could help them acquire additional years.
Researchers warn, however, that this should not be used to make individual predictions about when you'll die; rather, it should be used to obtain a sense of how someone's lifestyle might be improved.
