Impact of five modifiable lifestyle habits on the probability of cancer occurrence in a Japanese population-based cohort: Results from the JPHC study

Objective: The present work aims to provide 10-year estimates of the probability of cancer occurrence in the Japanese population based on age, sex, and the pattern of adherence to five healthy lifestyle habits. Methods: The study population consisted of 74,935 participants in the Japan Public Health Center-Based Prospective Study (aged 45 to 74. years) who answered a 5-year follow-up questionnaire about various lifestyle habits between 1995 and 1999. The relationship between five previously identified healthy lifestyle habits (never smoking, moderate or no alcohol consumption, adequate physical activity, moderate salt intake, and appropriate body mass index) and cancer occurrence was assessed using a sex-specific parametric survival model. Results: Compared to individuals not adhering to any of the five habits, never-smoking men had a nearly 30% reduction in the 10-year probability of cancer occurrence (e.g., 20.5% vs. 28.7% at age 70), and never-smoking women had a 16% reduction (e.g., 10.5% vs. 12.5% at age 70). Adherence to all five habits was estimated to reduce the 10-year probability of cancer occurrence by 1/2 in men and 1/3 in women. Conclusion: By quantifying the impact of lifestyle habits on the probability of cancer occurrence, this study emphasizes the importance of lifestyle improvement.