A new study published in the journal PLOS Medicine explores how diet impacts life expectancy.
The research uses findings from meta-analyses and data from the Global Burden of Disease study (2019) to model how life expectancy changes with sustained changes in dietary intake of various food sources. These food sources included fruits, vegetables, whole grains, refined grains, nuts, legumes, fish, eggs, milk/dairy, red meat, processed meat, and sugar-sweetened beverages.
The authors found that by shifting from a typical western diet to a more optimal diet, a 20-year old individual could increase their life expectancy by more than ten years. For a 60-year old individual, life expectancy could increase by eight years, and for an 80-year old, it could increase by about three and a half years. Their in-between diet model to accommodate those with difficulty making drastic diet alterations could still see a six to seven-year increase in life expectancy for a 20-year old.
The largest life expectancy increases were made by increasing legume, whole grain, and nut intake while decreasing red meat and processed meat consumption. The effect gradually lessens as individuals get older, so you can never start eating healthier too early.
You can read more from the study here.