By "donating" methyl groups, SAMe stimulates biochemical reactions that transform these molecules into bioactive substances. For example, when methyl groups are transferred from SAMe to certain phospholipids, phosphatidylcholine is produced. This important lipid is found in all cell membranes. It controls the pliancy of cell membranes. Stiff membranes do not transmit signals as well as pliant ones do. Thus, proper levels of phosphatidylcholine production are important. Since phosphatidylcholine ratios decrease with age, the methylation that SAMe causes may help protect and enhance cell integrity thereby preventing many of the "typical" signs of aging. This may also be an indication of how SAMe works to alleviate depression.

Levels of SAMe have also been shown to influence the body's production of melatonin, serotonin, and dopamine. These important neurotransmitters and hormones control sleep, mood and social interaction. All of which are effected by depression.

SAMe converts to Glutathione, the most important substance in the liver. Liver malfunction- whether caused by alcohol, viral infection or other disorder-is invariably accompanied by glutathione depletion. When glutathione is depleted, the liver simply can't do its job. The liver has special SAMe enzymes just for regenerating tissue through glutathione production.

Glutathione is also found in other organs. One of it's most important functions is to act as a potent free radical scavenger in the eye, where it protects against cataracts caused by UV sunlight. By providing the building blocks of glutathione, SAMe contributes to maintenance of this important natural antioxidant.

Many of the chemicals used to induce cancer in lab animals work by inhibiting SAMe. It is well documented that methyl deficiency produces liver cancer in rodents. Also, certain genes must be methylated in order to keep cancer from starting. After five weeks of a methyl-deficient diet, rats show cell changes. By the ninth week, transcripts of protooncogene genes (cancer genes c-myc and c-ras) start accumulating.

In treating osteoarthritis, SAMe protects both the synovial fluid and cartilage cells that are important to joint health. People suffering from osteoarthritis usually have damage to one or both of these important "joint cushions". Researchers theorize that SAMe, like NAC, protects synovial cells by reversing glutathione depletion. It may also protect synovial cells by blocking the enzymes that degrade cartilage. In the test tube, SAMe increases the number of chondrocytes (cartilage cells) and proteoglycans (protein). This suggests that SAMe treatment may reverse the underlying process of osteoarthritis by stimulating cartilage to grow.

One of the byproducts of normal SAMe metabolism is homocysteine. When there are adequate supplies of the metabolites, such as B6, B12 and folic acid, required for the synthesis and regeneration of SAMe, homocysteine breakdown occurs either through re-methylation or through trans-sulfuration. These processes turn homocysteine into glutathione, a powerful antioxidant. Therefore, supplementation with B6, B12 and folic acid may insure proper function of SAMe.