Abstract
Several B vitamins are essential in the one-carbon metabolism pathway, which is central to DNA methylation, synthesis, and repair. Moreover, an imbalance in this pathway has been linked to certain types of cancers. Here, we performed a meta-analysis in order to investigate the relationship between the intake of four dietary one-carbon metabolism-related B vitamins (B2, B6, folate, and B12) and the risk of esophageal cancer (EC). We searched PubMed, Web of Science, and Embase for relevant studies published through 1 March 2018. The odds ratio (OR) with 95% confidence interval (CI) for the highest versus the lowest level of each dietary B vitamin was then calculated. From 21 articles reporting 26 studies including 6404 EC cases and 504,550 controls, we found an inverse correlation between the consumption of vitamin B6 and folate and the risk of EC; this association was specific to the US, Europe, and Australia, but was not found in Asia. A dose-response analysis revealed that each 100 μg/day increase in folate intake reduced the risk of EC by 12%. Moreover, each 1 mg/day increase in vitamin B6 intake decreased the risk of EC by 16%. Surprisingly, we found that each 1 μg/day increase in vitamin B12 intake increased the risk of esophageal adenocarcinoma by 2%, particularly in the US and Europe, suggesting both geographic and histological differences. Together, our results suggest that an increased intake of one-carbon metabolism-related B vitamins may protect against EC, with the exception of vitamin B12, which should be consumed in moderation.
Highlights
Esophageal cancer (EC) is the ninth most common form of cancer and the sixth leading cause of cancer-related deaths worldwide, with an estimated 442,000 new cases and 440,000 deaths in 2013 [1].In addition, esophageal cancer (EC) was estimated to cause a loss of 9.8 million disability-adjusted life years, which places a major burden on healthcare systems around the world [1]
Vitamins B2, B6, B9, and B12 are essential nutrients involved in the one-carbon metabolism pathway, which plays a critical role in several key biological processes, including DNA stability and gene transcription [43], protein localization [44], and the degradation of small molecules [45]; these nutrients are believed to play an important role in preventing cancer
We found that the value in Australia (2.17 μg/day) was much lower than that in the US (4.64 μg/day) and Europe (8.11 μg/day), which were both higher than the recommended daily allowance (RDA) of vitamin B12 for adults (2.4 μg/day) [46]
Summary
Esophageal cancer (EC) is the ninth most common form of cancer and the sixth leading cause of cancer-related deaths worldwide, with an estimated 442,000 new cases and 440,000 deaths in 2013 [1].In addition, EC was estimated to cause a loss of 9.8 million disability-adjusted life years, which places a major burden on healthcare systems around the world [1]. Esophageal cancer (EC) is the ninth most common form of cancer and the sixth leading cause of cancer-related deaths worldwide, with an estimated 442,000 new cases and 440,000 deaths in 2013 [1]. New approaches to prevent or reduce the risk of EC are urgently needed. Epidemiological studies have identified many factors associated with an increased risk of EC, including gender, obesity, alcohol consumption, tobacco smoking, gastroesophageal reflux disease, Nutrients 2018, 10, 835; doi:10.3390/nu10070835 www.mdpi.com/journal/nutrients. Four specific B vitamins—B2 (riboflavin), B6 (pyridoxine), B9 (folate), and B12 (cobalamin)—have attracted attention. These four vitamins act in concert to regulate the one-carbon metabolism pathway, which helps maintain nucleotide synthesis and methylation [4]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
