It has been found from autopsy studies that women with Alzheimer's disease have low levels of the sex hormone estrogen in their brain tissue than women with a sound mental health. The research has been conducted by Dr. Rena Li and colleges at the University of Chicago.
Previous studies conducted on animal models have already revealed that deficiency of estrogen in the brain tissue can speed up the build up of 'plaque', which is a common characteristic of the disease.
An analysis of the serum estrogen levels revealed lower levels of the hormone in both patients with Alzheimer's and control subjects. Hence no correlation between the serum estrogen levels and the onset of the disease could be identified.
It has therefore been concluded that deficiency of estrogen in the brain rather than blood estrogen deficiency could be more specific in the pathogenesis behind Alzheimer's. This is supported by the fact that the brain cannot manufacture estrogen.
In order to assess the effect of reduced levels of estrogen in the brain on the onset and severity of the disease, the researchers developed mice that mimicked Alzheimer's disease through specialized breeding techniques. In addition, it lacked the capacity to synthesize estrogen as well.
Animals that were thus produced had reduced levels of estrogen in the brain and had a much earlier onset of plaque build up. To confirm that brain estrogen levels plays a significant role in the disease process, mice that underwent ovary removal was examined for the development of estrogen deficient brain disease.
As anticipated, only mice with deficient levels of estrogen in the brain developed the disease. The above finding perhaps serves to explain the failure of development of Alzheimer's in all post-menopausal women. It has further been hypothesized that certain specific genetic mechanisms could be responsible for the observed variability in the onset of the disease.
Most importantly, the results of the present study have highlighted the need for development of an estrogen formulation that can cross the blood brain barrier to be effective against the disease. The research team is currently assessing a number of natural estrogen products for the above-mentioned transport potential.