先前关于多不饱和脂肪酸（PUFA）与癌症发病率之间关系的流行病学研究并不一致。我们在大型前瞻性队列中研究了血浆 omega-3 和 omega-6 PUFA 与整体癌症和 19 种特定部位癌症发病率的关联。我们的研究纳入了 253,138 名符合条件的英国生物银行参与者。平均随访 12.9 年，29,838 名参与者被诊断患有癌症。 omega-3 和 omega-6 PUFA 的血浆水平以总脂肪酸的百分比（omega-3% 和 omega-6%）表示。在我们的主要模型中，omega-6% 和 omega-3% 均与总体癌症发病率呈负相关（HR per SD = 0.98，95% CI = 0.96-0.99；HR per SD = 0.99，95% CI = 0.97-1.00 ; 分别）。在 19 种可用的部位特异性癌症中，14 种与 omega-6% 相关，5 种与 omega-3% 相关，所有都表明呈负相关，但前列腺癌与 omega-3% 正相关（HR per SD = 1.03） , 95% CI = 1.01-1.05)。我们在英国生物银行进行的基于人群的队列研究表明，血浆 omega-6 和 omega-3 PUFA 与整体癌症和大多数特定部位癌症的发病率存在较小的负相关性，尽管也有明显的例外，例如前列腺癌。© 2024 作者（s）。约翰·威利出版的《国际癌症杂志》

Previous epidemiological studies on the associations between polyunsaturated fatty acids (PUFAs) and cancer incidence have been inconsistent. We investigated the associations of plasma omega-3 and omega-6 PUFAs with the incidence of overall and 19 site-specific cancers in a large prospective cohort. 253,138 eligible UK Biobank participants were included in our study. With a mean follow-up of 12.9 years, 29,838 participants were diagnosed with cancer. The plasma levels of omega-3 and omega-6 PUFAs were expressed as percentages of total fatty acids (omega-3% and omega-6%). In our main models, both omega-6% and omega-3% were inversely associated with overall cancer incidence (HR per SD = 0.98, 95% CI = 0.96-0.99; HR per SD = 0.99, 95% CI = 0.97-1.00; respectively). Of the 19 site-specific cancers available, 14 were associated with omega-6% and five with omega-3%, all indicating inverse associations, with the exception that prostate cancer was positively associated with omega-3% (HR per SD = 1.03, 95% CI = 1.01-1.05). Our population-based cohort study in UK Biobank indicates small inverse associations of plasma omega-6 and omega-3 PUFAs with the incidence of overall and most site-specific cancers, although there are notable exceptions, such as prostate cancer.© 2024 The Author(s). International Journal of Cancer published by John Wiley & Sons Ltd on behalf of UICC.