Yanping Li, M.D., Ph.D., from the Harvard T.H. Chan School of Public Health in Boston, and colleagues used data from the Nurses' Health Study and the Health Professionals Follow-up Study to define five low-risk lifestyle factors, and estimated hazard ratios for the association of total lifestyle score with mortality.
To what extent could a focus on prevention help to raise life expectancy in the US, which finds itself averaging 79.3 years, compared with Japan's 83.7?
They chose to focus on "smoking, excessive alcohol consumption, physical inactivity, poor diet, and obesity", because an analysis of 15 studies covering more than half a million people in 17 nations had concluded that these "unhealthy lifestyle factors" could account for around 60 percent of premature deaths.
The study analyzed data from 78,865 women followed over 27 years and 44,354 men followed over 34 years.
"This study underscores the importance of following healthy lifestyle habits for improving longevity in the US population", said Frank Hu, chair of the Department of Nutrition at Harvard Chan School and senior author of the study.
Each factor alone reduces the risk for cancer and heart disease but collectively could reduce the overall risk of death by 74-percent.
The study found that life expectancy at age 50 for participants who had not adopted any of the five healthy habits was 29 years for women and 25.5 years for men.
"Our findings have significant public health implications, because they demonstrate the great potential of diet and lifestyle changes in improving life expectancy", said senior researcher Dr. All participants were from the USA, and over the course of the roughly 30-year study period, researchers tracked their health and lifestyle habits, focusing especially on the five points mentioned above. 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.
"This study underscores the importance of following healthy lifestyle habits for improving longevity in the USA population".
Harvard researchers discovered that adherence to five lifestyle practices is associated with more than 10 years of increased longevity, as well as reduced risk for cancer and cardiovascular disease.