Impact of smoking and other lifestyle factors on life expectancy among japanese: findings from the Japan Collaborative Cohort (JACC) Study.
BACKGROUND
A number of lifestyle factors, including smoking and drinking, are known to be independently associated with all-cause mortality. However, it might be more effective in motivating the public to adopt a healthier lifestyle if the combined effect of several lifestyle factors on all-cause mortality could be demonstrated in a straightforward manner.


METHODS
We examined the combined effects of 6 healthy lifestyle behaviors on all-cause mortality by estimating life expectancies at 40 and 60 years of age among 62 106 participants in a prospective cohort study with a 14.5-year follow-up. The healthy behaviors selected were current nonsmoking, not heavily drinking, walking 1 hour or more per day, sleeping 6.5 to 7.4 hours per day, eating green leafy vegetables almost daily, and having a BMI between 18.5 to 24.9.


RESULTS
At age 40, we found a 10.3-year increase in life expectancy for men and a 8.3-year increase for women who had all 6 healthy behaviors, as compared with those who had only 0 to 2 healthy behaviors. Increases of 9.6 and 8.2 years were observed for men and women, respectively, at age 60 with all 6 healthy behaviors. When comparing currently nonsmoking individuals with 0 to 1 healthy behaviors, the life expectancy of smokers was shorter in both men and women, even if they maintained all 5 other healthy behaviors.


CONCLUSIONS
Among individuals aged 40 and 60 years, maintaining all 6 healthy lifestyle factors was associated with longer life expectancy. Smokers should be encouraged to quit smoking first and then to maintain or adopt the other 5 lifestyle factors.
Tamakoshi
Akiko
A
Department of Public Health, Aichi Medical University School of Medicine, Yazako, Nagakute-cho, Aichi-gun, Japan. tamaa@aichi-med-u.ac.jp
Kawado
Miyuki
M
Ozasa
Kotaro
K
Tamakoshi
Koji
K
Lin
Yingsong
Y
Yagyu
Kiyoko
K
Kikuchi
Shogo
S
Hashimoto
Shuji
S
D000328:Adult; D005260:Female; D005500:Follow-Up Studies; D015438:Health Behavior; D006801:Humans; D007564:Japan; D008017:Life Expectancy / Q000639:trends*; D008019:Life Style; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects*