Hall Megan N, Chavarro Jorge E, Lee I-Min, Willett Walter C, Ma Jing
Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, NY 10032, USA.
Cancer Epidemiol Biomarkers Prev. 2008 May;17(5):1136-43. doi: 10.1158/1055-9965.EPI-07-2803.
Fish is the main dietary source of long-chain n-3 fatty acids, which have been suggested to play a protective role in colorectal cancer development in laboratory and animal studies. Human studies have not shown consistent results. We examined the association between intakes of fish and n-3 fatty acids from fish and colorectal cancer risk in men enrolled in the Physicians' Health Study.
The Physicians' Health Study began as a randomized trial to examine the effect of aspirin and beta-carotene supplementation on cancer and cardiovascular disease. Fish intake was assessed at the 12-month follow-up with an abbreviated food-frequency questionnaire. Cox proportional hazards models were used to estimate multivariate relative risks for colorectal cancer for the categories of fish intake and quartiles of n-3 fatty acid intake.
During 22 years of follow-up, 500 men had a confirmed diagnosis of colorectal cancer. Fish intake was inversely associated with colorectal cancer risk [multivariate relative risk (95% confidence interval) for highest versus lowest category, 0.63 (0.42-0.95); P trend = 0.02] [corrected] The inverse association was observed for both colon and rectal cancers. Our findings for n-3 fatty acids were similar to those for fish; the multivariate relative risk (95% confidence interval) of total colorectal cancer for the highest versus lowest quartile of n-3 fatty acids was 0.74 (0.57-0.95; P trend = 0.01).
Our results from this long-term prospective study suggest that intakes of fish and long-chain n-3 fatty acids from fish may decrease the risk for colorectal cancer.
鱼类是长链n-3脂肪酸的主要饮食来源，在实验室和动物研究中，长链n-3脂肪酸被认为在结直肠癌的发生发展中起到保护作用。人体研究结果并不一致。我们在参与医师健康研究的男性中，研究了鱼类及鱼类中n-3脂肪酸的摄入量与结直肠癌风险之间的关联。
医师健康研究最初是一项随机试验，旨在研究阿司匹林和β-胡萝卜素补充剂对癌症和心血管疾病的影响。在12个月随访时，通过简化的食物频率问卷评估鱼类摄入量。采用Cox比例风险模型估计鱼类摄入量类别和n-3脂肪酸摄入量四分位数组的结直肠癌多变量相对风险。
在22年的随访期间，500名男性被确诊患有结直肠癌。鱼类摄入量与结直肠癌风险呈负相关[最高摄入量组与最低摄入量组的多变量相对风险（95%置信区间）为0.63（0.42 - 0.95）；P趋势 = 0.02][校正后]结肠癌和直肠癌均观察到这种负相关。我们关于n-3脂肪酸的研究结果与鱼类相似；n-3脂肪酸最高四分位数组与最低四分位数组的总结直肠癌多变量相对风险（95%置信区间）为0.74（0.57 - 0.95；P趋势 = 0.01）。
我们这项长期前瞻性研究的结果表明，鱼类及鱼类中长链n-3脂肪酸的摄入量可能会降低患结直肠癌的风险。
