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Intake of n‐3 and n‐6 polyunsaturated fatty acids and development of colorectal cancer by subsite: Japan Public Health Center–based prospective study
Author(s) -
Sasazuki Shizuka,
Inoue Manami,
Iwasaki Motoki,
Sawada Norie,
Shimazu Taichi,
Yamaji Taiki,
Takachi Ribeka,
Tsugane Shoichiro
Publication year - 2011
Publication title -
international journal of cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.475
H-Index - 234
eISSN - 1097-0215
pISSN - 0020-7136
DOI - 10.1002/ijc.25802
Subject(s) - polyunsaturated fatty acid , colorectal cancer , medicine , rectum , gastroenterology , prospective cohort study , confidence interval , population , physiology , cancer , endocrinology , fatty acid , biology , biochemistry , environmental health
To date, epidemiologic studies investigating intake of n‐3 and n‐6 polyunsaturated fatty acids and risk of colorectal cancer are limited, and results remain inconsistent. This is the first prospective study to show the association by subsite (proximal colon, distal colon, rectum). To clarify the role of n‐3 and n‐6 polyunsaturated fatty acids intake in colon carcinogenesis, we conducted a large, population‐based prospective study, characterized by high fish consumption and a wide range of n‐3 polyunsaturated fatty acids intakes. Subjects were followed from response to a lifestyle questionnaire in 1995–1999 through 2006. During 827,833 person‐years of follow‐up (average 9.3 years), we identified 1,268 new colorectal cancer cases (521 colon and 253 rectal for men; 350 colon and 144 rectal for women). Compared to the lowest quintile, the relative risk and 95% confidence interval of developing cancer among the fifth quintile of marine n‐3 polyunsaturated fatty acids intake were 0.60 and 0.31–1.14, respectively ( p for trend = 0.04) in the colon in women and 0.35 and 0.14–0.88 ( p for trend = 0.05) and 1.82 and 0.79–4.20 ( p for trend = 0.16) in the proximal and distal colon, respectively, in men. For rectal cancer, the dose response for marine n‐3 polyunsaturated fatty acids s was unclear; rather, we observed U‐shaped associations in men and women. We found no evidence that n‐6 polyunsaturated fatty acids increases or the n‐3/n‐6 ratio decreases the risk of colorectal cancer. Our results suggest that intake of marine n‐3 polyunsaturated fatty acids may be inversely related to the risk of cancer in the proximal site of the large bowel.