叶酸代谢在前列腺癌中的作用

Roles of folate metabolism in prostate cancer

流行病学调查发现叶酸具有预防前列腺癌的作用,但强化叶酸饮食后,前列腺癌的患病风险却在增加。从美国国家癌症研究中心查询到的数据表明,叶酸具有预防前列腺癌的作用,但通过检索Medline文献最新研究证据,结合流行病学数据表明,人体摄入非天然叶酸强化食品后,增加了前列腺癌的患病风险。另外,根据美国健康和营养调查数据库分析得到血清叶酸在饮食强化前后的含量,结合前列腺癌的发病率,显示叶酸可能在前列腺癌发病中扮演双重角色。而且,越来越多的证据表明,较高的血清叶酸水平可以促进前列腺癌的发生和进展,逐步推翻了流行病学关于叶酸降低前列腺癌发病风险的结论。但二者关系还需要通过进一步研究来澄清。本文就现阶段叶酸代谢在前列腺癌中的双重作用做一综述。

Epidemiological surveys show that folic acid can prevent prostate cancer,but fortified folic acid may increase the risk of the malignancy. The physician data queries from the National Cancer Institute of the USA describe folate as protective against prostate cancer,whereas its synthetic analog,folic acid,is considered to increase prostate cancer risk when taken at levels easily achievable by eating fortified food or taking over-the-counter supplements. We review the current literature to examine the effects of folate and folic acid on prostate cancer,help interpret previous epidemiologic data,and provide a clarification regarding the apparently opposing roles of folate for patients with prostate cancer. A literature search was conducted in Medline to identify studies investigating the effect of nutrition and specifically folate and folic acid on prostate carcinogenesis and progression. In addition,the National Health and Nutrition Examination Survey database was analyzed for the trends in serum folate levels before and after mandatory fortification. Folate likely plays a dual role in prostate carcinogenesis. There remains some conflicting epidemiologic evidence regarding folate and prostate cancer risk. However,there is growing experimental evidence that higher circulating folate levels can contribute to prostate cancer progression. Further research is needed to clarify these complex relationships.