S-adenosyl-L-methionine in the treatment of Alzheimer's disease.

Patients with Alzheimer's disease (AD) have an apparent abnormality possibly representing an increase in the average fluidity of their cell membranes. Changes in membrane fluidity of similar magnitude to those observed in AD have been noted to lead to marked alterations in cell function. Therefore, the changes in fluidity observed in AD may be related to the symptoms of that disorder, representing either an underlying cause of dysfunction or cellular attempts to compensate for dysfunction in AD. To test these possibilities, we administered S-adenosyl-L-methionine (SAMe), an agent shown to increase membrane fluidity in animals, to patients with AD. Treatment with SAMe led to marked increases in membrane fluidity. However, it produced neither improvement nor worsening of symptoms. The results imply that while SAMe may be useful for other conditions associated with altered membrane fluidity (such as normal aging), changing membrane fluidity per se is not likely to lead to marked changes in symptoms in AD.