One view is that stress is the enemy of longevity. From the Library of Halexandria: “Stress is an undesirable commodity — if only because it’s not beneficial to wellness. Thus it stands to reason that a reduction in stress in someone’s life might lead to greater health, and thereby allow one to live longer.” Some, including myself, tend to disagree, holding instead that animal (including human) longevity is correlated with having and meeting a healthy level of challenge – not too little and not too much stress. Too little mental, physical or life stress is apt to lead to inaction and then one’s neurons and muscle cells will atrophy and die. That is why regular exercise and taking on intellectual and life challenges tend to extend longevity. On the other hand if life challenges are just too overwhelming, an animal may be unable to cope and simply choose to die. We know about the health-damaging effect of constant mobilization of cortisol in response to stress.
Imagine that stress is somehow quantified and laid out on the x axis of a graph, and the y axis is probable lifespan in years. The graph would resemble a normal distribution, e.g. a bell-shaped curve where the largest probable lifespan corresponds to the best amount of stress. Way too little or too much stress would correlate with shorter life spans.
A recent study done by a team at Rockefeller University seems to indicate that the same principal holds on the cellular level for retinal cells. When the cell experiences stress in the endoplasmic reticulum (ER), depending on the condition of the cell and the nature of the stress the cell can choose to die or to live longer by mobilizing its defense mechanisms. The study and its conclusions is explained in a university newswire release that can be found here. “The team, including Bertrand Mollereau, who is now a professor at the Ã‰cole Normale SupÃ©rieure de Lyon in France, believes that a mechanism underlying this protection may involve antioxidant genes that protect retinal neurons from ultraviolet radiation and free radicals. When these neurons are exposed to mild ER stress, the team showed that they upregulate genes that shield them from the substances’ harmful effects. “As in neurodegenerative diseases, when photoreceptor neurons die, they may never be replaced,” explains graduate student Alexis Gambis, who also worked on the project. “The antioxidant upregulation is one way neurons have evolved to protect themselves from exogenous stress and it’s especially important in the eye, which receives damaging UV energy from the sun(ref).”
Stress is not one thing. An analysis reviewing the results of 300 independent studies identifies five distinct categories of stress:
1. “Acute time-limited stressors: lab challenges such as public speaking or mental math.
2. Brief naturalistic stressors: real-world challenges such as academic tests.
3. Stressful event sequences: a focal event such as loss of a spouse or major natural disaster gives rise to a series of related challenges that people know at some point will end.
4. Chronic stressors: pervasive demands that force people to restructure their identity or social roles, without any clear end point – such as injury resulting in permanent disability, caring for a spouse with severe dementia, or being a refugee forced from one’s native country by war.
5. Distant stressors: traumatic experiences that occurred in the distant past yet can continue modifying the immune system because of their long-lasting emotional and cognitive consequences, such as child abuse, combat trauma or having been a prisoner of war(ref). “
As far as my personal stress regimen is concerned, thankfully they mostly fall in the first two categories. Most of the daily stress challenges I face are self-generated: doing at least 47 minutes of mildly cardiovascular exercise, doing many hours of focused longevity research, taking on difficult scientific topics and writing these blog entries. In addition my challenges include keeping my treatise up to date on a weekly basis, constantly learning more about molecular biology, genetics, genomics, biochemistry and the other expanding areas of science underlying longevity science, handling family finances and taxes, being the handyman in two houses, yard work, commuting back and forth to my New Hampshire lake home in the summer, and leading a balanced all-around family life while doing all that. I believe the stress of keeping up with these challenges is contributing to keeping me young and fully functional. External stress-generating challenges of the second and third types sometime loom very important for me as they do for other humans, such as sickness on the part of my wife or loved one, concerns about money, concerns about the state of the world. The key thing is to not let those start to overwhelm me. I am fortunate not to be faced with stress of the fourth type. And I have done enough psychotherapy and internal re-examination to assure that I am free from stress of the fifth type.