美國研究人員7月5日在美國《胃腸病學》雜志上發(fā)表研究報告稱,，大量攝入葉酸可以降低患結(jié)腸癌的風險。
美國癌癥學會的研究人員在1999年至2007年對近10萬人展開了研究,，其中一部分人有大量攝入葉酸的習慣。在這期間，1023人被診斷出患結(jié)腸癌,。結(jié)果顯示，在兩年內(nèi)人們攝入多少葉酸對罹患結(jié)腸癌的影響差別不大,，但堅持大量攝入葉酸兩年以上者,，患結(jié)腸癌的風險明顯降低。
研究報告的主要作者,、美國癌癥學會的維多利亞·史蒂文斯指出,，不管是自然攝入葉酸，還是服用營養(yǎng)補充劑形式的葉酸,，都具有預防結(jié)腸癌的功能,。只要攝入的葉酸達到一定總量，即可降低罹患結(jié)腸癌的風險,。
其他學者則認為這一發(fā)現(xiàn)尚存爭議,，因為目前至少已有一項研究表明，葉酸補充劑對結(jié)腸腺瘤的影響不明顯,，而結(jié)腸腺瘤是結(jié)腸癌的“前奏”,。
作為一種水溶性維生素B，葉酸是細胞正常生長以及DNA（脫氧核糖核酸）合成和修復所需的重要營養(yǎng)成分,，它普遍存在于某些自然食品中,，但一些補充劑也可以提供葉酸。（生物谷Bioon.com）
生物谷推薦原文出處：
Gastroenterology doi:10.1053/j.gastro.2011.04.004
High Levels of Folate From Supplements and Fortification Are Not Associated With Increased Risk of Colorectal Cancer
Victoria L. StevensMarjorie L. McCullough, Juzhong Sun, Eric J. Jacobs, Peter T. Campbell, Susan M. Gapstur
Background & Aims Folate intake has been inversely associated with colorectal cancer risk in several prospective epidemiologic studies. However, no study fully assessed the influence of the high levels of folate that are frequently consumed in the United States as a result of mandatory folate fortification, which was fully implemented in 1998, and the recent increase in use of folate-containing supplements. There is evidence that consumption of high levels of folic acid, the form of folate used for fortification and in supplements, has different effects on biochemical pathways than natural folates and might promote carcinogenesis. Methods We investigated the association between folate intake and colorectal cancer among 43,512 men and 56,011 women in the Cancer Prevention Study II (CPS-II) Nutrition Cohort; 1023 were diagnosed with colorectal cancer between 1999 and 2007, a period entirely after folate fortification began. Cox proportional hazards regression was used to calculate multivariate hazards ratios (RR) and 95% confidence interval (CI).
