“What doesn’t kill you makes you stronger” is a phrase that contains more than a grain of truth. It describes the theory of hormesis — the process whereby organisms exposed to low levels of stress or toxins become more resistant to tougher challenges.
The theory of hormesis has been around for decades, but has long been met with skepticism or downright suspicion. In recent years, however, biologists have pieced together a clear molecular explanation of how it works, and hormesis has finally been accepted as a fundamental principle of biology and biomedicine.
As an example, exposing mice to small doses of gamma ray radiation shortly before irradiating them with very high levels of gamma rays actually decreases the likelihood of cancer. A similar effect occurs when dioxin is given to rats.
The biochemical mechanisms by which hormesis works are not well understood. It is thought that a low dose of a toxin can trigger certain repair mechanisms in the body, and these mechanisms, having been initiated, are efficient enough that they not only neutralize the toxin’s effect, but can even repair other defects not caused by the toxin.
One of the areas where the concept of hormesis has been explored extensively is aging. It is thought that exposing cells to mild stress could result in the adaptive or hormetic response that has anti-aging effects. Some of the mild stresses that might work for this include heat shock, irradiation, pro-oxidants, hypergravity, food restriction, and even exercise. Sources:
* New Scientist August 6, 2008
Dr. Mercola’s Comments:
This is a fascinating concept, which highlights the problem inherent with so much of our medical interventions, whether natural or conventional. The stereotypical thought pattern that “if a little is good, more must be better,” usually turns out to be the precise converse of the truth.
Many have already been harmed by excessive exposure to toxins and forms of radiation that have been previously deemed “safe.” Think of:
* Smoking * Vaccinations * Water fluoridation * Mercury amalgams, and now * Cell phone radiation
Your body is a finely tuned instrument, and even seemingly insignificant changes can sometimes create major repercussions, for better or worse. Like a spider’s web, if you pluck one strand, the entire web vibrates. Pluck too hard and it breaks the strand, collapsing the intricate design of the whole.
Hormesis – To Impel Change
Hormesis — from the ancient Greek word hormáein, meaning “to set in motion, impel, urge on” — is the term for favorable biological responses resulting from low exposures to toxins and other stressors. A toxin showing hormesis thus has the opposite effect in small doses than in large doses.
Homeopathy could be considered as an example here, where even a highly toxic (natural) substance can be used to produce dramatic healing responses in your body because it is reduced to such a degree that only the energetic essence of it remains; there’s enough to impel a healing change, but not nearly enough to tip the scales too far to cause damage.
Hormesis then, is the biological phenomena where an otherwise adverse or detrimental influence is beneficial when applied at low levels – just enough to set something into motion.
The concept of biological hormesis is as important as that of homeostasis for the survival of an organism. Your body’s ability to resist and adapt appropriately to both internal and external stresses is essential for good health, and the hallmark of aging is your body’s inability to withstand stress, which starts to degrade it.
The hormetic phenomenon in aging is characterized as beneficial responses to stress through physiological adaptations, as exemplified in lifespan extension by calorie restriction or exercise, for example. According this schema, your body’s ability to adapt is developed during the resistance period.
This notion corresponds to the evolutionary view on the survival for the fittest theory, where survival is dependent on metabolic and defensive adaptation to harmful stress.
The beneficial effects of hormesis can easily be observed with physical exercise. Proper exercise can improve your body function, boost metabolism, increase immune function, deter a wide variety of diseases, extend the average lifespan, and create resistance to oxidative stress. Too much exhaustive exercise, however, can be as harmful as too little or no exercise – another topic I’ve already discussed in some detail. (For more information see this link.)