On Mitohormesis

A little stress improves our biochemistry: "Recent evidence suggests that calorie restriction and specifically reduced glucose metabolism induces mitochondrial metabolism to extend life span in various model organisms, including Saccharomyces cerevisiae, Drosophila melanogaster, Caenorhabditis elegans and possibly mice. In conflict with Harman's free radical theory of aging (FRTA), these effects may be due to increased formation of reactive oxygen species (ROS) within the mitochondria causing an adaptive response that culminates in subsequently increased stress resistance assumed to ultimately cause a long-term reduction of oxidative stress. This type of retrograde response has been named mitochondrial hormesis or mitohormesis, and may in addition be applicable to the health-promoting effects of physical exercise in humans and, hypothetically, impaired insulin/IGF-1-signaling in model organisms. Consistently, abrogation of this mitochondrial ROS signal by antioxidants impairs the lifespan-extending and health-promoting capabilities of glucose restriction and physical exercise, respectively. In summary, the findings discussed in this review indicate that ROS are essential signaling molecules which are required to promote health and longevity. Hence, the concept of mitohormesis provides a common mechanistic denominator for the physiological effects of physical exercise, reduced calorie uptake, glucose restriction, and possibly beyond."

Link: http://www.ncbi.nlm.nih.gov/pubmed/20350594


Unfortunately as a mega-industry has grown around antioxidants this research will go unnoticed by the majority of the populace. Here in Australia chemist shops will keep stocking their shelves with antioxidants and other dubious 'supplements' and the media health gurus and neighborhood 'alternate' medical practitioners and herbalists will keep pushing the benefits of antioxidants. It seems as if a health 'breakthrough' leads to commercial products then that research gets publicised far and wide, but if more recent research threatens that market it gets ignored buried. Over the past decade I have probably seen thousands of advertisements pushing the benefits of antioxidants, but I doubt they will now be replaced by warnings that antioxidant supplements may shorten your life. Calcium supplements are another case in point. There have been major advertising campaigns over the years urging women to take regular calcium supplements. Although recent research has shown that women who take calcium supplements are at a significantly higher risk of high blood pressure and strokes I am yet to see such a warning in any of the chemist shops that stock this product. And as these types of supplements are usually promoted by non-professional and unregulated media health gurus and neighborhood 'alternate' medical practitioners there is no legal requirement or established structure to keep up to date with the latest research. Indeed it seems more common for newspaper 'health advisers' etc. to keep pushing the same old line year after year. Just look at coffee - demonized by health experts for decades but now coffee consumption has been linked with lower incidences of bowel cancer and it helps rehabilitate alcohol damaged kidneys. Yet still one of the most common 'health tips' seems to be to reduce or cut out coffee/caffeine. I'm glad my health regime includes three or four strong coffees before midday (none after midday as caffeine can effect the body for up to 12 hours), no vitamin or mineral supplements except for an occasional B12 shot (I'm on a vegetarian / reduced calorie uptake diet), an no antioxidants except what I get through my normal diet. At least for those in the know antioxidants can now be seen for what they are - overpriced quack medicine that actually does the opposite of what it is promoted for.

Posted by: Brett Pritchard at June 5th, 2011 7:40 PM

Post a comment; thoughtful, considered opinions are valued. New comments can be edited for a few minutes following submission. Comments incorporating ad hominem attacks, advertising, and other forms of inappropriate behavior are likely to be deleted.

Note that there is a comment feed for those who like to keep up with conversations.