Researchers at the University of Pennsylvania and Stanford University reviewed the medical records of nearly 5 million patients in two large hospital systems and found that prostate cancer patients who had undergone androgen deprivation therapy (ADT) were almost twice as likely to be diagnosed with Alzheimer’s than those patients who did not opt for that treatment approach.
“It’s hard to determine the precise amount of increased risk in just one study and important to note that this study does not prove causation,” said lead study author Kevin Nead, MD, a resident at Penn’s Perelman School of Medicine. “But considering the already high prevalence of Alzheimer’s disease in older men, any increased risk would have significant public health implications.”
The study’s results were published in the December 7 issue of the Journal of Clinical Oncology.
ADT has become a popular prostate cancer treatment protocol in recent years, as it has been shown to effectively suppress male hormones, like testosterone, that often stimulate prostate cell growth. About a half-million men in the U.S. are undergoing the treatment at any given time.
Earlier research has shown that drastically lowering androgen levels, specifically testosterone, can lead to impotence, obesity, diabetes, high blood pressure, heart disease, depression, and even cognitive disorders, but Nead’s team and their colleagues at Stanford are the first to uncover a link between ADT and Alzheimer’s.
The team focused on nearly 17,000 prostate cancer patients treated at Mt. Sinai Hospital and the Stanford health system. Of those, about 2,400 had undergone the ADT protocol, which researchers compared with a control group of non-ADT patients. The two groups were matched by age and other factors.
In the years following the prostate cancer diagnosis and treatment, researchers found ADT patients were about 88 percent more likely to be diagnosed with Alzheimer’s than the control group. The results did not differ when patients from each hospital system were analyzed separately.
Testosterone is believed to contribute to brain cell health, so researchers theorize that drastically reducing levels of the hormone could leave those cells less able to combat the process leading to Alzheimer’s.
To learn more about maintaining your optimal brain health, see “Beyond Sudoku” in our November 2015 issue.