Wednesday, February 10, 2016
Wisdom Wednesday: Hormesis
Hormesis is a term used by toxicologists for a process in which exposure to a low dose of a chemical agent or environmental factor that is damaging at higher doses induces an adaptive beneficial effect on the cell or organism. In the fields of biology and medicine hormesis is defined as an adaptive response of cells and organisms to a moderate (usually intermittent) stress. Examples include ischemic preconditioning, exercise, dietary energy restriction and exposures to low doses of certain phytochemicals.
In laymen’s terms it is the phenomena where by the body adapts to a stressor and improves its’ ability to resist that stressor in the future.
I recently referred to the term hormesis in my blog on the Ayurvedic herb Schisandra posted on Jan. 20.
Physical exercise is probably the best example. As I have mentioned in several of my blogs, I am a cyclist. For the most part cycling is an endurance sport where you maintain a moderate pace for long periods of time. I use spinning classes to create hormesis. They are of shorter duration, but much higher intensity. Spinning creates stress on my cardiovascular and musculoskeletal systems forcing them to adapt and become stronger. This improves my cycling endurance and also benefits my general health. However, if I exceed my Vmax (maximum heart rate) or stay above my aerobic zone for more than 10 minutes at a time I can damage my body.
Toxins can have the same effect. Snake handlers routinely are bitten by venomous snakes. As long as the amount of venom is limited to non-lethal doses, their bodies adapt and they acquire an immunity to the specific toxins.
This is also how patients adapt to medications. Virtually all medications are toxins, impairing normal human physiology. Most of the time, the impairment is the desired effect of the drug – beta blockers reduce the force of the normal heart contraction, reducing blood pressure. Of course, avoiding a lethal dose is the first issue in medication. However, over time, the body adapts to the stress created by the drug and can overcome the medication. Then the medication “stops working” and a new drug is introduced, maybe as a replacement or in combination with the initial medication. This is the birth of polypharmacy; a topic I have written about frequently.
Environmental toxins can also act in the same manner. We have all adapted to ever increasing mercury levels in our bodies. Again, lethal levels must be avoided and environmental toxins often exceed our ability to adapt resulting in various cancers and birth defects.
Another issue is the presence of multiple stressors simultaneously. Your body may be able to adapt to slowly increasing radiation from the sun as our ozone layer is depleted. However, what happens when that is in combination with estrogen and antibiotics in our drinking water, biphenyls in our food and the thousands of other environmental toxins we are exposed to daily?
Science has yet to address the global aspect of this issue. The standards for research require that all variables but the ‘one’ being investigated be controlled for the study to be valid.
The Bottom Line:
Hormesis is a distinct physiological benefit of life. Use it to your benefit by stressing your body intermittently and moderately. However, there are limits to the body’s ability to adapt. Constant high levels of stressors will cause the body to falter and eventually fail.