Can eating certain healthy foods consistently help you to live longer? According to a new study published Wednesday in the New England Journal of Medicine, the answer is yes.

Researchers at the Harvard T.H. Chan School of Public Health monitored the eating habits of almost 50,000 women and more than 25,000 men from the Nurses’ Health Study and the Health Professionals Follow-up Study over a 12-year period. The participants, who ranged in age from 30 to 75 at the start of the study, were then tracked for a subsequent 12 years. The researchers compared the information they had on dietary changes made during the first 12 years to the number of deaths and their causes during the follow-up period.

Participants were given points according to how well they incorporated components of three different healthy-eating approaches: the U.S. Dietary Guidelines, the Mediterranean Diet, and the DASH (Dietary Approaches to Stop Hypertension) diet. All of these plans generally emphasize eating whole grains, fruits and vegetables, and lean protein and limiting unhealthy fat, sodium, sugar-sweetened and processed foods and red meat.

People whose point tallies improved by 20 percent over the 12-year follow-up period (meaning their diets contained more healthy elements and fewer unhealthy ones) were 8 to 17 percent less likely to die during that period of time.

Eating more whole grains, vegetables, fruits, and fish resulted in the largest improvements in diet scores.


It's Never Too Late to Start Eating Healthier

More good news: Those whose scores rose by 20 percent on the Dietary Guidelines and Mediterranean Diet point scale also had a reduced risk of dying from cardiovascular disease. “This is the first study to demonstrate that improvement in these three diet scores over time is associated with reduced risk of total and cardiovascular mortality,” says study lead author Mercedes Sotos-Prieto, Ph.D., an assistant professor in food and nutrition science at Ohio University and visiting scientist at Harvard T.H Chan School of Public Health.

People who had the lowest diet quality at the start of the study and who improved their eating habits the most got an even bigger payoff: Their risk of dying prematurely declined from 15 to 28 percent. In addition, the longer healthy dietary changes were maintained, the greater the reduction in risk. And as might be expected, those who adopted more unhealthy dietary habits saw a 6 to 12 percent greater risk of dying during the follow-up period.

“One of the main points of this study is it’s never too late to make changes to your diet,” says Dana Hunnes, Ph.D., R.D., an adjunct assistant professor of nutrition at UCLA’s Fielding School of Public Health, who was not involved with the study. “Instituting modest, incremental changes can add up, regardless of age.”

Small Changes Make a Difference

What’s more, even small shifts in your daily diet can help add years to your life. For example, according to the researchers, swapping one serving of red meat a day for a serving of nuts or beans would lead to a 20 percent improvement in diet quality. And just eating more fruits and vegetables—going from no daily servings to four servings of fruit or five servings of vegetables—raised the scores by 10 percent. Other changes that can make a difference include cutting out sugar-sweetened drinks, consuming one less alcoholic drink a day, and eating more foods high in healthy fat, such as olive oil and avocado.