But is testosterone replacement therapy the answer?
Low testosterone levels may make men vulnerable to developing Alzheimer’s disease, a long-term study in the journal Neurology suggests. Researchers found that, in a group of U.S. men followed for decades, those with low blood levels of free testosterone had an elevated risk of developing Alzheimer’s disease. Free testosterone is a form of the hormone that is not bound to a protein in the blood and is therefore available to body tissue.
Whether giving older men testosterone replacement therapy might stave off Alzheimer’s disease is far from clear, but the study authors say their findings should spur research into the possibility. They also urge caution, however, noting that although scientists had hoped hormone replacement therapy would lower the risk of dementia in older women, this has not been borne out in recent clinical trials.
The current study included 574 men, ages 32 to 87, who were free from Alzheimer’s disease and followed for an average of 19 years. The researchers found that for every 10- unit increase in a man’s free testosterone, his risk of later developing Alzheimer’s disease dipped 26%, even with factors such as age, education, and smoking considered. According to the authors, the findings are bolstered by past research in animals and humans suggesting that natural testosterone may protect brain cells and limit the buildup of Alzheimer’s linked beta-amyloid proteins.
