A recent study has linked low levels of free testosterone with an increased risk for the development of Alzheimers disease.
Investigators at the U.S. National Institute on Aging (Bethesda, MD, USA) tested free testosterone levels in a group of 574 men aged 32 to 87 who had participated in the Baltimore Longitudinal Study of Aging. These patients had been observed for a mean period of 19 years. Over this period 54 of the men developed Alzheimers disease.
Comparing testosterone levels in those who contracted Alzheimers disease to those in men who did not develop the disease, the authors found that for every 50% increase in free testosterone in the blood, there was a 26% reduction in the risk of developing the disease. Low testosterone levels were detected up to ten years before onset of symptoms of Alzheimers disease. These findings were published in the January 27, 2004, issue of Neurology.
The mechanism by which testosterone may protect against Alzheimers disease has not been determined, and the authors did not recommend taking the hormone as a preventative measure.
