title: Risk of lung cancer and consumption of vegetables and fruit in Japanese: A pooled analysis of cohort studies in Japan.
abstract: International reviews have concluded that consumption of fruit and vegetables might decrease the risk of lung cancer. However, the relevant epidemiological evidence still remains insufficient in Japan. Therefore, we performed a pooled analysis of data from four population-based cohort studies in Japan with >200 000 participants and >1700 lung cancer cases. We computed study-specific hazard ratios by quintiles of vegetable and fruit consumption as assessed by food frequency questionnaires. Summary hazard ratios were estimated by pooling the study-specific hazard ratios with a fixed-effect model. In men, we found inverse associations between fruit consumption and the age-adjusted and area-adjusted risk of mortality or incidence of lung cancer. However, the associations were largely attenuated after adjustment for smoking and energy intake. The significant decrease in risk among men remained only for a moderate level of fruit consumption; the lowest summary hazard ratios were found in the third quintile of intake (mortality: 0.71, 95% confidence interval 0.60-0.84; incidence: 0.83, 95% confidence interval 0.70-0.98). This decrease in risk was mainly detected in ever smokers. Conversely, vegetable intake was positively correlated with the risk of incidence of lung cancer after adjustment for smoking and energy intake in men (trend P, 0.024); the summary hazard ratio for the highest quintile was 1.26 (95% confidence interval 1.05-1.50). However, a similar association was not detected for mortality from lung cancer. In conclusion, a moderate level of fruit consumption is associated with a decreased risk of lung cancer in men among the Japanese population.
authors.affiliation: Department of Preventive Medicine, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Wakai
authors.affiliation: Division of Epidemiology, Department of Public Health and Forensic Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Yumi
authors.initials: Y
authors.lastname: Sugawara
authors.affiliation: Division of Epidemiology, Department of Public Health and Forensic Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Ichiro
authors.initials: I
authors.lastname: Tsuji
authors.affiliation: Department of Public Health, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Tamakoshi
authors.affiliation: Epidemiology and Prevention Division, Research Center for Cancer Prevention and Screening, National Cancer Center, Tokyo, Japan.
authors.forename: Taichi
authors.initials: T
authors.lastname: Shimazu
authors.affiliation: Department of Preventive Medicine, Kyushu University Faculty of Medical Sciences, Fukuoka, Japan.
authors.forename: Keitaro
authors.initials: K
authors.lastname: Matsuo
authors.affiliation: Department of Epidemiology and Preventive Medicine, Gifu University Graduate School of Medicine, Gifu, Japan.
authors.forename: Chisato
authors.initials: C
authors.lastname: Nagata
authors.affiliation: Department of Epidemiology and Prevention, Clinical Research Center, National Center for Global Health and Medicine, Tokyo, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Mizoue
authors.affiliation: Department of Preventive Medicine, Faculty of Medicine, Saga University, Saga, Japan.
authors.forename: Keitaro
authors.initials: K
authors.lastname: Tanaka
authors.affiliation: Epidemiology and Prevention Division, Research Center for Cancer Prevention and Screening, National Cancer Center, Tokyo, Japan.|Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors.forename: Manami
authors.initials: M
authors.lastname: Inoue
authors.affiliation: Epidemiology and Prevention Division, Research Center for Cancer Prevention and Screening, National Cancer Center, Tokyo, Japan.
authors.forename: Shoichiro
authors.initials: S
authors.lastname: Tsugane
authors.affiliation: Epidemiology and Prevention Division, Research Center for Cancer Prevention and Screening, National Cancer Center, Tokyo, Japan.
authors.forename: Shizuka
authors.initials: S
authors.lastname: Sasazuki
mesh_terms: D000328:Adult; D000368:Aged; D044466:Asian People; D015331:Cohort Studies; D004032:Diet; D004034:Diet Surveys; D005260:Female; D005638:Fruit; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008175:Lung Neoplasms / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D014675:Vegetables
keywords: Cohort studies; fruit; lung neoplasms; meta-analysis; vegetables