Hormones and Alzheimer’s
Is there a connection?
Do we age because we lose our hormones or do we lose our hormones because we age? This is an interesting question because as a population we are living longer than ever before, but the question really needs to be about our quality of life as we age.
Today, everyone seems to know someone that has been diagnosed with, or is suffering from, the effects of Alzheimer’s disease or dementia. It is a terrible and painful disease for all involved as it destroys brain function and is ultimately fatal.
There are several factors identified and commonly associated with brain abnormalities resulting in Alzheimer’s:1
- Beta-amyloid plaques building up between neurons in the brain;
- Neurofibrillary tangles within the neurons (the tangles are composed of the hyper phosphorylated tau protein, which eventually kills the neurons);
- Impaired glucose metabolism in the brain (a degree of insulin resistance);
- Poor blood circulation to the brain.
A 2013 study in the Journal of Neurology states that women are eight times more likely to get Alzheimer’s than men, and men with low testosterone are three times more likely to suffer from dementia. Testosterone is a vaso-dilator, opening blood vessels and increasing blood flow to the brain resulting in more oxygen and nutrition to the brain.
The connection between metabolism (mitochondria) and Alzheimer’s disease is also being established. In 2000, Suzanne de la Monte, MD, MPH, was recognized for her innovative research entitled Oxidative Injury and Anti-Oxidant Rescue of the Aging Brain in which she stated that for every Alzheimer’s patient the energy metabolism in the mitochondria was decreased; the amount of enzyme formation was decreased; and the number of mitochondria was decreased.
Thyroid hormones increase the metabolic activities of almost all the tissues of the body – including the number and activity of mitochondria. It also increases the total membrane surface area of the mitochondria in direct proportion to the increased metabolic rate of your body. As the Textbook of Medical Physiology states, “It seems almost to be an obvious deduction that principal function of thyroxin [thyroid hormone] might be simply to increase the number and activity of mitochondria.”
Millions of Americans are experiencing hypothyroid symptoms and are not being treated because their lab work appears to be in the normal ranges. Thyroid dysfunction has been implicated as a cause of reversible cognitive impairment.
In his book Solved: The Riddle of Alzheimer’s Disease, Mark Starr, MD, states the following on how hormones help prevent Alzheimer’s:
- Vitamin D3 (a hormone) increases the excretion of beta-amyloid from the brain.
- Beta-amyloid-secretion is impaired by both testosterone and estradiol.
- Testosterone and estradiol increase alpha secretase activity. Beta-secretase is an enzyme that prevents production of beta amyloid.
- Testosterone and estradiol increase neprilysin, an enzyme that degrades beta-amyloid.
- Testosterone and progesterone inhibit the hyper phosphorylation of tau protein.
- Testosterone and estradiol improve brain cell glucose metabolism.
- Testosterone and estradiol improve blood flow to the brain.
Self-care and prevention are the keys to optimal health. Paying close attention to how your body feels, and seeking assistance around optimizing your physiology is the key to a long, healthy, and happy life.
Tiffany Baggs is a nurse practitioner with the Preventive Medicine Centers in Palm Springs, CA and Carlsbad, NM. She can be reached at (760) 320.4292. For more information visit www.hormonedoctor.com.
Reference: 1) Solved: The Riddle of Alzheimer’s Disease by Mark Starr, MD.