Poring over data from more than 123,000 people in two different studies, Harvard researchers identified five lifestyle practices — not smoking, maintaining a low body mass index (BMI), exercising regularly, drinking alcohol in moderation, and eating well — that can prolong one’s life by a decade or more. Their findings are published in Circulation, a journal associated with the American Heart Association.

“Americans have a shorter life expectancy compared with residents of almost all other high-income countries. We aim to estimate the impact of lifestyle factors on premature mortality and life expectancy in the U.S. population,” write Frank Hu, of the Harvard T.H. Chan School of Public Health, and colleagues.

The researchers drew upon health information from the 78,865 people in the Nurses’ Health Study (1980-2014) and the 44,354 people in the Health Professionals Follow-up Study (1986-2014). They matched that data with information about death rates and lifestyle scores from the National Health and Nutrition Examination Surveys (NHANES) from 2013-2014 and with U.S. Centers for Disease Control and Prevention’s WONDER database.

For a 50-year-old woman who adopted none of the five practices, life expectancy was 29 years, while men who did none of the five could expect to live 25.5 years. Among people who followed all five prescribed lifestyle practices, researchers estimated that women would live another 43.1 years, and men another 37.6 years. That’s a difference of more than 14 years for women and more than 12 years for men who lived healthier lives in this regard.

“The more low-risk factors a person had, the longer his or her projected life span. For example, a 50-year-old woman with four healthy factors could expect to live, on average, to around 89, those with three to 87, and those with two to 84,” reported Nicholas Bakalar in the New York Times, covering the study. The article notes that unfortunately, less than 2 percent of the people in the study had all five low-risk factors. One third had two or fewer.

“The question is how to improve behavior,” Hu told the Times. “Individual changes are not sufficient. We need dramatic changes in food, physical activity and social environment to make healthy choices more accessible, affordable, and normative.”

In an interview with TODAY, lead author Yanping Li, also of the Harvard school, said that an hour a week of moderate physical activity was associated with three or four more years of life expectancy. Three hours of exercise weekly was associated with six more years, and six hours a week of exercise with eight more years.