Here is more on how prolonged mental and emotional stress can take a toll on our health. Going beyond what we know of its ill effects on blood pressure, development of cardiovascular diseases and type 2 diabetes, stress is now also being seen as a prime suspect in development of Alzheimer’s disease.
Research done on a mice model by scientists at University of California, San Diego School of Medicine clearly showed that mice exposed to repeated stress exhibited larger production and accumulation of insoluble tau protein clumps inside their brain cells, which was a physiological marker in Alzheimer’s. (1)
What exactly are tau proteins? Tau proteins are such proteins that are found primarily in the nerve cells (neurons) of the central nervous system. Their main function is to stabilise the microtubules. (2)
Microtubules are made of tubulin material and give a cells its structure, shape and support -- somewhat like the skeletal structure of a cell, apart from providing a platform on which various biochemical processes take place. (3)
Which brings us to the link between tau protein and Alzheimer’s -- tau proteins are able to stabilize microtubules through two types of chemical reactions, isoforms and phosphorylation.
Broadly speaking, phosphorylation refers to the addition of a phosphate group to a protein or any organic molecule that leads to regulating the triggers of these proteins and prevents the mechanisms of various diseases.
However hyperphosphorylation of tau proteins can result in a self-assembly of clumps and tangles of filaments, which are involved in the pathogenesis of Alzheimer's disease. (4)
Robert A. Rissman, PhD , the lead author of the study and assistant professor of neurosciences, had this to say. “In the mouse models, we found that repeated episodes of emotional stress, which has been demonstrated to be comparable to what humans might experience in ordinary life, resulted in the phosphorylation and altered solubility of tau proteins in neurons. These events are critical in the development of NFT pathology in Alzheimer's disease.” (5)