Folate cancer risk and the greek god Proteus: a tale of two chameleons

摘要

Evidence indicates that an abundant intake of foodstuffs rich in folate conveys protection against the development of colorectal cancer, and perhaps some other common cancers as well. The issue is a complex one however, since some observations in animal and human studies demonstrate that an overly abundant intake of folate among those who harbor existing foci of neoplasia might instead produce a paradoxical promotion of tumorigenesis. The pharmaceutical form of the vitamin, folic acid, might affect the process in a manner that is distinct from natural forms of the vitamin, although this remains a speculative concept. Our limited understanding of this complex relationship is unfortunately impeding efforts to move ahead with widespread folic acid fortification, but this may be necessary to ensure that such programs are instituted in a safe manner.