America is one of the wealthiest countries worldwide, yet Americans have a shorter average life expectancy (79.3 years) than residents of almost all other high-income countries, including Japan, Canada and Norway.
Researchers point out that the U.S. healthcare system focuses heavily on drug discovery and disease management; however, a greater emphasis on prevention could change this life expectancy trend.
The new study aimed to quantify how much healthy lifestyle factors might be able to boost longevity in the U.S.
“This study underscores the importance of following healthy lifestyle habits for improving longevity in the U.S. population,” said study senior author Dr. Frank Hu, chair of the Department of Nutrition at the Harvard T.H. Chan School of Public Health.
“However, adherence to healthy lifestyle habits is very low. Therefore, public policies should put more emphasis on creating healthy food, built, and social environments to support and promote healthy diet and lifestyles.”
Dr. Hu and co-authors looked at 34 years of data from 78,865 women and 27 years of data from 44,354 men participating in, respectively, the Nurses’ Health Study and the Health Professionals Follow-up Study.
They looked at how five low-risk lifestyle factors — not smoking, low body mass index (18.5-24.9 kg/m2), at least 30 minutes or more per day of moderate to vigorous physical activity, moderate alcohol intake (for example, up to about one 5-ounce glass of wine per day for women, or up to two glasses for men), and a healthy diet — might impact mortality.
For study participants who didn’t adopt any of the low-risk lifestyle factors, the team estimated that life expectancy at age 50 was 29 years for women and 25.5 years for men.
But for those who adopted all five low-risk factors, life expectancy at age 50 was projected to be 43.1 years for women and 37.6 years for men.
In other words, women who maintained all five healthy habits gained, on average, 14 years of life, and men who did so gained 12 years, compared with those who didn’t maintain healthy habits.
Compared with those who didn’t follow any of the healthy lifestyle habits, those who followed all five were 74% less likely to die during the study period.
The study authors also found that there was a dose-response relationship between each individual healthy lifestyle behavior and a reduced risk of early death, and that the combination of all five healthy behaviors was linked with the most additional years of life.
“Quantifying the association between healthy lifestyle factors and longer life expectancy is important not only for individual behavioral changes but also for health communicators and policy makers,” Dr. Hu said.
“It is critical to put prevention first. Prevention, through diet and lifestyle modifications, has enormous benefits in terms of reducing occurrence of chronic diseases, improving life expectancy as shown in this study, and reducing healthcare costs.”