Impact of Smoking and Other Lifestyle Factors on Life Expectancy among Japanese: Findings from the Japan Collaborative Cohort (JACC) Study

Akiko Tamakoshi,Kotaro Ozasa,Shogo Kikuchi,Miyuki Kawado,Shuji Hashimoto,Yingsong Lin,Kiyoko Yagyu,Koji Tamakoshi

doi:10.2188/jea.je20100017

Abstract

BackgroundA 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.MethodsWe 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.ResultsAt 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.ConclusionsAmong 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.

Highlights

Unhealthy lifestyle behaviors such as cigarette smoking,[1,2] excessive alcohol drinking,[3,4] physical inactivity,[5] too much or too little sleep,[6,7] low consumption of green leafy vegetables,[8,9] and overweight[10,11] are associated with increased risk of all-cause mortality
The current study presents life expectancies according to the number of healthy lifestyle behaviors, using data from a largescale population-based cohort followed for 14.5 years
The results showed that life expectancy rises as the number of healthy behaviors increases

Summary

Introduction

Unhealthy lifestyle behaviors such as cigarette smoking,[1,2] excessive alcohol drinking,[3,4] physical inactivity,[5] too much or too little sleep,[6,7] low consumption of green leafy vegetables,[8,9] and overweight[10,11] are associated with increased risk of all-cause mortality. We recently reported the combined effects of modifiable lifestyle factors on all-cause mortality.[14] As compared with people with 0 to 2 healthy lifestyle behaviors (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 a body mass index (BMI) between 18.5 to 24.9), men and women with 6 healthy behaviors had 58% and 51% respective reductions in the risk of all-cause mortality. Among these behaviors, smoking may be the best known risk factor. Smokers should be encouraged to quit smoking first and to maintain or adopt the other 5 lifestyle factors

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