Free radicals attach themselves to nucleic acids and alter methylation. Methylation is a biochemical process that starts with methionine. When methionine reacts with ATP, SAMe is formed. In methylation, these groups break off from SAMe to catalyze other reactions. The leftover product eventually becomes homocysteine, which can be toxic if not converted.
B vitamins are necessary for the conversion of homocysteine.
Homocysteine can also be converted by betaine, a product of choline. When this occurs, abnormal activation and deactivation of genes occur. This finding has major implications for aging as well as cancer since DNA damage occurs naturally with age. Free radicals do most of their damage by inhibiting methylation. Maintaining and enhancing methylation is the next therapy for aging and disease, including cancer and heart disease.