Why women have more Alzheimer's disease than men: gender and mitochondrial toxicity of amyloid-beta peptide.

The main risk factors for developing Alzheimer's disease (AD) are age and gender. The incidence of the disease is higher in women than in men, and this cannot simply be attributed to the higher longevity of women versus men. Thus, there must be a specific pathogenic mechanism to explain the higher incidence of AD cases in women. In this regard, it is notable that mitochondria from young females are protected against amyloid-beta toxicity, generate less reactive oxygen species, and release less apoptogenic signals than those from males. However, all this advantage is lost in mitochondria from old females. Since estrogenic compounds protect against mitochondrial toxicity of amyloid-beta, estrogenic action may be important in protecting cells from amyloid-beta toxicity and suggests a possible treatment or prevention strategy for AD. Unfortunately, to date, clinical trials with Ginkgo biloba and other estrogenic therapies have not proved successful in treating AD. As such, more experiments and clinical trials are indeed warranted to find conditions in which estrogenic compounds may be useful to prevent or treat AD.