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)
The aggregates are similar to neurofibrillary tangles or NFTs, modified protein structures that are one of the physiological hallmarks of Alzheimer's disease.
Lead author Robert A. Rissman, PhD, assistant professor of neurosciences, said the findings may at least partly explain why clinical studies have found a strong link between people prone to stress and development of sporadic Alzheimer's disease (AD), which accounts for up to 95 percent of all AD cases in humans.
Dr. Rissman was also of the opinion that this study explained to some extent why clinical studies have found a strong link between those who are prone to stress and development of sporadic Alzheimer’s.
He added that the hippocampus of the person was the first to be affected by the aberration in tau pathology and this was the region where maximum cell death and shrinkage was reported. Hippocampus is the area in our brain which among other things is responsible for the formation, organization and storage of memories.
Another observation was that not all types caused the same extent of damage. Surprisingly, acute and short term stress did not leave any lasting debility on the brain cells and were on the whole considered beneficial for the brain as it was thought good for maintaining brain plasticity and enabling faster learning.
However, aging and prolonged stress made the neural circuits weak and less resilient from repeated stress episodes.
The stress triggers most affected two key corticotropin-releasing factor receptors. This in effect shows the target for potential therapies to aim at.
Drugs that could modulate the activities of these two receptors would probably benefit those prone to stress.
SOURCES:
1. Chronic Stress Spawns Protein Aggregates Linked to Alzheimer's; Science Daily News; Web April 2012; http://www.sciencedaily.com/releases/2012/03/120326160819.htm
2. Plaques and Tangles; American Health Assistance Foundation – Alzheimer’s Disease Research; Web April 2012; http://www.ahaf.org/alzheimers/about/understanding/plaques-and-tangles.html
3. Microtubules; NCBI Resources - Bookshelf; Web April 2012; http://www.ncbi.nlm.nih.gov/books/NBK9932
4. Tau Protein, Alzheimer's Update 2012; ED Informatics; Web April 2012; http://www.edinformatics.com/news/tau_protein.htm
5. Chronic Stress Spawns Protein Aggregates Linked to Alzheimer’s; UC San Diego - News Center; Web April 2012; http://ucsdnews.ucsd.edu/pressreleases/chronic_stress_spawns_protein_aggregates_linked_to_alzheimers
Technical report of the study may be accessed at:
1. Corticotropin-Releasing Factor Receptor-Dependent Effects Of Repeated Stress On Tau Phosphorylation, Solubility, And Aggregation; Proceedings of the National Academy of Sciences (US) - PNAS; Web April 2012; http://www.pnas.org/content/early/2012/03/22/1203140109
INFORMATION IN THIS ARTICLE IS NOT MEDICAL ADVICE. ALL INFORMATION GIVEN IS TO BE CHECKED WITH YOUR DOCTOR BEFORE IMPLEMENTING OR TAKING THEM AS STANDARD OR VERIFIED.
Mamta Singh is a published author of the books Migraines for the Informed Woman – Tips From A Sufferer: ISBN: 978-81-291-1517-1 (Publisher: Rupa & Co. URL: http://www.amazon.com/Migraines-Informed-Woman-Tips-Sufferer/dp/8129115174/ref=sr_1_2?ie=UTF8&s=books&qid=1298990756&sr=1-2), Mentor Your Mind – Tested Mantras For The Busy Woman: ISBN: 978-81-207-5973-2 (Publisher: Sterling Publishers; URL: http://www.amazon.com/Mentor-Your-Mind-Tested-Mantras/dp/8120759737/ref=sr_1_1?ie=UTF8&qid=1316063179&sr=8-1) and the upcoming Women’s Complete Fitness Guide (Publisher: Hay House India).
She is also a seasoned business, creative and academic writer. She is a certified fitness instructor, personal trainer & sports nutritionist through IFA, Florida USA. Mamta is an NCFE-certified Holistic Health Therapist SAC Dip U.K. She is the lead writer and holds Expert Author status in many well-received health, fitness and nutrition sites.
She runs her own popular blogs on migraines in women and holistic health. Mamta holds a double Master's Degree in Commerce and Business. She is a registered practitioner with the UN recognised Art of Living Foundation. Please visit www.mamtasingh.com/
Reviewed May 10, 2012
by Michele Blacksberg RN
Edited by Jody Smith