title: The relationship between vegetable/fruit consumption and gallbladder/bile duct cancer: A population-based cohort study in Japan.
abstract: Vegetable and fruit consumption may have a protective effect against several types of cancers. However, the effect on biliary cancers is unclear. We investigated the association of vegetable/fruit consumption with the risks of gallbladder cancer (GBC), intrahepatic bile duct cancer (IHBDC) and extrahepatic bile duct cancer (EHBDC) in a population-based prospective cohort study in Japan. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using the Cox proportional hazard model, and the exposure level was categorized into quartiles, with the lowest group used as the reference. A total of 80,371 people aged 45 to 74 years were enrolled between 1995 and 1999, and followed up for 1,158,632 person-years until 2012, during which 133 GBC, 99 IHBDC, and 161 EHBDC cases were identified. Increased consumption of total vegetable and fruit was significantly associated with a decreased risk of EHBDC (HR = 0.49; 95% CI: 0.29-0.81 for the highest group; p trend = 0.005). From the analysis of relevant nutrients, significantly decreased risk of EHBDC was associated with folate and insoluble fiber (HR = 0.48, 0.53; 95% CI: 0.28-0.85, 0.31-0.88 for the highest group; p trend = 0.010, 0.023; respectively), and a significant trend of decreased EHBDC risk associated with vitamin C was observed (p trend = 0.029). No decreased risk of GBC and IHBDC was found. Our findings suggest that increased vegetable/fruit consumption may decrease a risk of EHBDC, and folate, vitamin C, and insoluble fiber might be key contributors to the observed protective effect.
authors: Department of Environmental Medicine and Population Sciences, Graduate School of Medicine, Osaka University, Suita Osaka, Japan.
authors: Takeshi
authors: T
authors: Makiuchi
authors: Department of Environmental Medicine and Population Sciences, Graduate School of Medicine, Osaka University, Suita Osaka, Japan.
authors: Tomotaka
authors: T
authors: Sobue
authors: Department of Environmental Medicine and Population Sciences, Graduate School of Medicine, Osaka University, Suita Osaka, Japan.
authors: Tetsuhisa
authors: T
authors: Kitamura
authors: Division of Nutritional Sciences, Graduate School of Sagami Women's University, Sagamihara Kanagawa, Japan.
authors: Junko
authors: J
authors: Ishihara
authors: Epidemiology and Prevention Group, Center for Public Health Sciences, National Cancer Center, Chuo-ku Tokyo, Japan.
authors: Norie
authors: N
authors: Sawada
authors: Epidemiology and Prevention Group, Center for Public Health Sciences, National Cancer Center, Chuo-ku Tokyo, Japan.
authors: Motoki
authors: M
authors: Iwasaki
authors: Epidemiology and Prevention Group, Center for Public Health Sciences, National Cancer Center, Chuo-ku Tokyo, Japan.
authors: Shizuka
authors: S
authors: Sasazuki
authors: Epidemiology and Prevention Group, Center for Public Health Sciences, National Cancer Center, Chuo-ku Tokyo, Japan.
authors: Taiki
authors: T
authors: Yamaji
authors: Epidemiology and Prevention Group, Center for Public Health Sciences, National Cancer Center, Chuo-ku Tokyo, Japan.
authors: Taichi
authors: T
authors: Shimazu
authors: Epidemiology and Prevention Group, Center for Public Health Sciences, National Cancer Center, Chuo-ku Tokyo, Japan.
authors: Shoichiro
authors: S
authors: Tsugane
mesh_terms: D000328:Adult; D000428:Alcohol Drinking / Q000453:epidemiology; D001205:Ascorbic Acid; D001650:Bile Duct Neoplasms / Q000453:epidemiology* / Q000517:prevention & control; D002277:Carcinoma / Q000453:epidemiology* / Q000517:prevention & control; D002769:Cholelithiasis / Q000453:epidemiology; D015897:Comorbidity; D003920:Diabetes Mellitus / Q000453:epidemiology; D004032:Diet; D004043:Dietary Fiber; D005260:Female; D005492:Folic Acid; D005500:Follow-Up Studies; D005638:Fruit; D005706:Gallbladder Neoplasms / Q000453:epidemiology* / Q000517:prevention & control; D006525:Hepatitis, Viral, Human / Q000453:epidemiology; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008019:Life Style; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012907:Smoking / Q000453:epidemiology; D011795:Surveys and Questionnaires; D014675:Vegetables
chemical_list: D004043:Dietary Fiber; D005492:Folic Acid; D001205:Ascorbic Acid
keywords: JPHC; Japanese; extrahepatic bile duct cancer; fruit; gallbladder cancer; intrahepatic bile duct cancer; prospective study; vegetable