Folate, homocysteine, endothelial function and cardiovascular disease. What is the link?

Elevated plasma homocysteine concentrations are associated with an increase d risk of cardiovascular disease, but the relationship has not been proven to be causal. Folate is the strongest nutritional and pharmacological deter minant of plasma homocysteine concentrations, which also interact with the genetic variation in methylenetetrahydrofolate reductase (MTHFR). Endotheli al dysfunction due to reduced nitric oxide bioavailability is an early feat ure of vascular pathology. This can be assessed noninvasively by measuremen t of flow-mediated dilatation. Human studies on folic acid, homocysteine an d endothelial function are reported. It is proposed that folic acid in high doses may have beneficial effects on endothelial function, which are indep endent of homocysteine lowering. (C) 2001 editions scientifiques et medical es Elsevier SAS.