Low Testosterone in Older Men Risk Factor for Alzheimer’s disease

Kathleen Blanchard's picture

In a study that examined cognitive decline among Chinese men, scientists found a link between Alzheimer’s disease and low testosterone levels. The study authors believe they have found a link between low levels of the hormone and memory decline that can lead to dementia in older men.

Low testosterone levels alone were not implicated for leading to dementia or Alzheimer’s disease. In the study, researchers identified older men with less testosterone as being more vulnerable to the disease.

John E. Morley, M.D., director of the division of geriatric medicine at Saint Louis University and a study co-investigator says, “The take-home message is we should pay more attention to low testosterone, particularly in people who have memory problems or other signs of cognitive impairment.”


Men included in the study with mild cognitive impairment were found to progress to dementia within a year. When researchers checked blood tissue levels of testosterone, they noted all of the men had lower levels than those whose memory did not worsen. Another finding was elevated levels of the ApoE 4 (apolipoprotein E) protein that also coincides with increased risk of Alzheimer’s disease and high blood pressure.

Testosterone Previously Linked to Impaired Memory

Testosterone has previously been linked to cognitive impairment in men. The new findings substantiate past studies that the hormone may have a protective affect on memory.

Of 153 men enrolled in the study, 47 were identified with mild cognitive impairment – ten of those men developed dementia within a year, leading the researchers to the finding that low testosterone could be a risk factor for Alzheimer’s disease that deserves further attention. All of the participants were age 55 or over.

Dr. Morley says the study is “exciting”, and shows “that a low level of testosterone is one of the risk factors for Alzheimer’s disease.” He is advocating for studies to measure the effectiveness of testosterone replacement for preventing Alzheimer’s disease and improving mild memory loss in older men.

Saint Louis University