[Effects of folic acid on cerebrovascular and cancer risks].

Homocysteine increase is associated with an elevated risk of cerebro-vascular (CV) disease as well as osteoporosis, dementia and depression. However, most secondary prevention trials did not show any CV benefit to decrease homocysteine levels through folate administration, with the possible exception of stroke. Reasons for these failures are analysed. Moreover, folate acid could decrease the risk of colon, breast and prostate cancers mainly in wine drinkers, whereas it increases the growth of preneoplasic cells of the latter cancers. In conclusion, folate acid does not benefit patients for secondary prevention of CV or malignant diseases but it still has to be proven that it could benefit patients for primary prevention.