Switching from an unhealthy to a healthy diet in middle age could add a decade to a person’s life, and eating more nuts is one of a few key dietary changes resulting in the biggest gains in life expectancy, according to a new study (1).

The study, published in Nature Food, was based on a model used to estimate how sustained dietary changes could affect a person’s life expectancy.

It analysed data from 467,354 participants in the UK Biobank – a large-scale database and research resource containing genetic, lifestyle and health information, on people living in the United Kingdom.

The model found that if a 40-year-old changed from an ‘unhealthy diet’ to a ‘longevity-associated dietary pattern’, and kept this up over time, they could live an extra 10 years (10.4 years for women and 10.8 years for men).

Making the same changes at age 70 years could also extend life expectancy – at about half of that achieved by 40-year-olds (or around five years), suggesting it’s never too late to adjust food choices.

The modelling found that regularly eating more nuts and whole grains, and less sugar-sweetened beverages and processed meats led to the biggest improvements in life expectancy.

“Our findings suggest that these food groups should be specific targets for clinicians in the guidance of patients, and policy makers in developing public health policy” (1).

Switching from an ‘average diet’ (rather than an explicitly unhealthy one) to the ‘longevity-associated dietary pattern’ also increased life expectancy – by about three years, for both women and men.

The ‘longevity-associated dietary pattern’ prioritises milk and dairy, vegetables, nuts, legumes, whole grains, fruit, fish, and white meat, with lower intakes of eggs, red meat, sugar-sweetened beverages, refined grains, and processed meat.

Did you know? An earlier modelling study, published in 2021 by the same researchers, found that consuming 25g of nuts per day, from 20 years of age, could increase life expectancy by almost two years (2).

The bottom line:

Shifting to a healthier diet, and maintaining this over time, could boost life expectancy by up to 10 years. The largest gains can be obtained from ‘do-able’ dietary changes, like eating more nuts and whole grains, and less sugar-sweetened beverages and processed meat.

A good place to start? Add a handful of nuts to your day, every day!

A major review found eating a handful of nuts a day, compared to eating no nuts, was associated with a 22% reduced risk of dying from all causes (3).