BACKGROUND & AIMS There is an unclear association between intake of fish and long-chain n-3 polyunsaturated fatty acids (n-3 LC-PUFAs) and colorectal cancer (CRC). We examined the association between fish consumption, dietary and circulating levels of n-3 LC-PUFAs, and ratio of n-6:n-3 LC-PUFA with CRC using data from the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. METHODS Dietary intake of fish (total, fatty/oily, lean/white) and n-3 LC-PUFA were estimated by food frequency questionnaires given to 521,324 participants in the EPIC study; among these, 6291 individuals developed CRC (median follow up, 14.9 years). Levels of phospholipid LC-PUFA were measured by gas chromatography in plasma samples from a sub-group of 461 CRC cases and 461 matched individuals without CRC (controls). Multivariable Cox proportional hazards and conditional logistic regression models were used to calculate hazard ratios (HRs) and odds ratios (ORs), respectively, with 95% CIs. RESULTS Total intake of fish (HR for quintile 5 vs 1, 0.88; 95% CI, 0.80-0.96; Ptrend = .005), fatty fish (HR for quintile 5 vs 1, 0.90; 95% CI, 0.82-0.98; Ptrend = .009), and lean fish (HR for quintile 5 vs 1, 0.91; 95% CI, 0.83-1.00; Ptrend = .016) were inversely associated with CRC incidence. Intake of total n-3 LC-PUFA (HR for quintile 5 vs 1, 0.86; 95% CI, 0.78-0.95; Ptrend = .010) was also associated with reduced risk of CRC, whereas dietary ratio of n-6:n-3 LC-PUFA was associated with increased risk of CRC (HR for quintile 5 vs 1, 1.31; 95% CI, 1.18-1.45; Ptrend < .001). Plasma levels of phospholipid n-3 LC-PUFA was not associated with overall CRC risk, but an inverse trend was observed for proximal compared with distal colon cancer (Pheterogeneity = .026). CONCLUSIONS In an analysis of dietary patterns of participants in the EPIC study, we found regular consumption of fish, at recommended levels, to be associated with a lower risk of CRC, possibly through exposure to n-3 LC-PUFA. Levels of n-3 LC-PUFA in plasma were not associated with CRC risk, but there may be differences in risk at different regions of the colon.

中文翻译：

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在大量欧洲人群中，食用鱼和长链 n-3 多不饱和脂肪酸与降低结直肠癌风险相关。


背景与目的 鱼类摄入量与长链 n-3 多不饱和脂肪酸 (n-3 LC-PUFA) 和结直肠癌 (CRC) 之间的关联尚不清楚。我们利用欧洲癌症与营养前瞻性调查 (EPIC) 队列的数据，研究了鱼类消费、饮食和 n-3 LC-PUFA 循环水平以及 n-6:n-3 LC-PUFA 比率与 CRC 之间的关联。方法 通过向 EPIC 研究中的 521,324 名参与者发放的食物频率调查问卷来估算鱼类（总含量、脂肪/油性、瘦肉/白色）和 n-3 LC-PUFA 的膳食摄入量；其中，6291 人罹患 CRC（中位随访时间 14.9 年）。通过气相色谱法测量了 461 名 CRC 病例和 461 名匹配的无 CRC 个体（对照）的血浆样本中的磷脂 LC-PUFA 水平。多变量 Cox 比例风险和条件逻辑回归模型分别用于计算风险比 (HR) 和比值比 (OR)，置信区间为 95%。结果 鱼的总摄入量（五分位数 5 vs 1 的 HR，0.88；95% CI，0.80-0.96；Ptrend = .005）、多脂鱼（五分位数 5 vs 1 的 HR，0.90；95% CI，0.82-0.98；Ptrend = .009）和瘦鱼（五分位数 5 vs 1 的 HR，0.91；95% CI，0.83-1.00；Ptrend = .016）与 CRC 发病率呈负相关。总 n-3 LC-PUFA 的摄入量（五分位数 5 vs 1 的 HR，0.86；95% CI，0.78-0.95；Ptrend = 0.010）也与降低 CRC 风险相关，而 n-6:n 的饮食比例-3 LC-PUFA 与 CRC 风险增加相关（五分位数 5 vs 1 的 HR，1.31；95% CI，1.18-1.45；Ptrend < .001）。磷脂 n-3 LC-PUFA 的血浆水平与总体 CRC 风险无关，但与远端结肠癌相比，观察到近端结肠癌呈相反趋势（Pheterogenity = .026）。 结论 在对 EPIC 研究参与者的饮食模式进行分析时，我们发现按推荐水平定期食用鱼类与降低 CRC 风险相关，这可能是通过接触 n-3 LC-PUFA 实现的。血浆中 n-3 LC-PUFA 水平与 CRC 风险无关，但结肠不同区域的风险可能存在差异。