Testosterone may prevent the accumulation of amyloid, the central suspect in Alzheimer’s disease, according to a study.
When the brains of Alzheimer’s patients are examined post-mortem, they reveal build up of deposits of a protein called amyloid. The normal form of amyloid occurs naturally in the human body, but when it accumulates it appears to be toxic to nerve cells. The damage caused is thought to set the scene for Alzheimer’s disease.
But sex hormones may prevent the build up of amyloid, say researchers at New York University. They have found that testosterone suppression, which occurs during therapy for prostate cancer (because some cancers are stimulated to grow by the hormone) has the side effect of raising amyloid levels in blood. This suggests that maybe the reason why Alzheimer’s is more common in older people is that it’s kept at bay by estrogen, in women, and testosterone, in earlier life. Only when levels of hormones drop, do amyloid levels increase to a toxic level.
The men on testosterone-reducing therapy will be followed for several years to see if they do develop Alzheimer’s disease. If so, this will suggest that adding testosterone might offer some protection. Some studies – although not all – indicate that hormone replacement therapy in women can reduce the risk of Alzheimer’s. It may be that this approach that will work for men too.