Increased intake of vitamin B6 from diet and supplements may reduce the risk of colorectal cancer by over 50%
Almost 15,000 people took part in the study, which reported that increased blood levels of vitamin B6s active form, pyridoxal 5'-phosphate (PLP), were significantly associated with a reduced risk of colorectal cancer. The study follows similar findings from Scotland-based researchers published last year. Researchers from the University of Edinburgh, Western General Hospital (Edinburgh) and the University of Aberdeen reported that increased intakes of vitamin B6 from dietary and supplements may reduce the risk of colorectal cancer by over 20%.
The researchers led by Dr J Lee from Brigham and Women's Hospital and Harvard Medical School, collaborated with scientists from Harvard School of Public Health, Jean Mayer U.S. Department of Agriculture Human Nutrition Research Center on Aging at Tufts University, and GlaxoSmithKline R&D on the study. The researchers prospectively evaluated the link between blood PLP levels and risk of colorectal cancer amongst 14,916 men. During the course of the study, 197 incident cases of colorectal cancer were documented, and these cases were then compared to 371 healthy.
Lee and his co-workers report that PLP levels were positively correlated with blood levels of folate and vitamin B12. PLP levels were also slightly inversely correlated with blood levels of homocysteine, and the inflammatory markers CRP, tumor necrosis factor-alpha receptor 2, and interleukin-6. Regarding the incidence of colorectal cancer, plasma PLP levels were inversely linked with risk of colorectal cancer, said the researchers. Indeed, when increasing levels were found to decrease the risk by 8%, 58%, and 51% they said. “In conclusion, vitamin B6 may protect against colorectal cancer independent of other one-carbon metabolites and inflammatory biomarkers,” they concluded. The study is published in the April 2009 issue of the journal Cancer Epidemiology, Biomarkers & Prevention.