Human longevity. Long have men sought to predict or control their own lifespans or improve their vitalities. Many cultures have invented remedies to cure various illnesses or to repel the embrace of Death which inevitably finds us all. In the 17th century, King Charles II took to a combination of alcohol with powdered skull bones of a human to improve his lifespan. In De Agri Cultura (“On Agriculture”) by Marcus Cato the Elder circa 160 BC, he espouses cabbage as a cure-all for maladies, injuries, and the expected aches and pains of aging. He wrote:
If you eat [cabbage] chopped, washed, dried, and seasoned with salt and vinegar, nothing will be more wholesome… This will benefit you, allow no ill to remain in the body, and promote digestion; and will heal any ill that may be inside… Also if you are bilious, if the spleen is swollen, if the heart is painful, or the liver, or the lungs, or the diaphragm — in a word, it will cure all the internal organs which are suffering. (p. 147)
Since the advent of The Scientific Method, which was designed to promote objective measurement and reproducible results, remedies of this nature have been abandoned and debunked, but not scientifically replaced to a widely generalizable extent; however, a recent study has been published which sheds light on a statistically significant indicator of health and lifespan.
Every cell biology class teaches its students that “the mitochondrion is the powerhouse of the cell”; however, in our ever-expanding understanding of cellular and molecular biology, the mitochondrion has been shown to be so much more. Humanin, a mitochondrial-derived signaling peptide, has been shown to have a protective role regarding many age-related diseases, such as Alzheimer’s Disease, atherosclerosis, and stroke.1-2 In a previous study, humanin was shown to prevent cognitive decline in mammalian models and to be associated with reduction of cognitive decline in humans.3 The study published on June 23, 2020 tests in further detail the effects of elevated humanin levels in worms, mice, naked mole rats, rhesus macaques, and humans.
In worms, rodents, and non-human primates, humanin levels are correlated to an increase in longevity and a decrease in body fat composition, body size, and litter size. It seems the introduction of extra humanin successfully improved longevity in mice only when administered to young subjects, though the middle-aged subjects did show higher metabolism, leaner body composition (higher lean muscle to fat ratio), and decreased inflammatory markers indicative of age-related diseases. The conductors of this study examined levels of humanin in a cohort of human centenarians (individuals who have seen over a century of life) and in the children of centenarians. The children of centenarians showed higher levels of humanin, which has been shown to inversely correlate with age-related diseases (cancer, CVD, kidney disease, Alzheimer’s Disease, etc.) and positively correlate to healthspan and lifespan.
So what happens next? A plethora of possibilities lies before us in the light of new discoveries. Will humanin become an integral part of daily multivitamins? Will humanin someday be remembered in the same humor as we now examine Cato’s cabbage remedies? If humanin is proven in future studies to be a fantastically beneficial supplement, will corporations take advantage of the everyman’s fears of his own mortality, or will they embrace a utopian vision and help usher in the Age of Longevity from the Information Age. Humanin has the potential to support a new chapter in the story of humanity, but it remains to be seen whether it will be a chapter of united progress, self-inflicted contestation, or some affect yet to be defined.
Chai GS, Duan DX, Ma RH, Shen JY, Li HL, Ma ZW, Luo Y, Wang L, Qi XH, Wang Q, Wang JZ, Wei Z, Mousseau DD, et al. Humanin attenuates alzheimer-like cognitive deficits and pathological changes induced by amyloid β-peptide in rats. Neurosci Bull. 2014; 30:923-35. https://doi.org/10.1007/s12264-014-1479-3
Xu X, Chua CC, Gao J, Hamdy RC, Chua BH. Humanin is a novel neuroprotective agent against stroke. Stroke. 2006; 37:2613-19. https://doi.org/10.1161/01.STR.0000242772.94277.1f
Yen K, Wan J, Mehta HH, Miller B, Christensen A, Levine ME, Salomon MP, Brandhorst S, Xiao J, Kim SJ, Navarrete G, Campo D, Harry GJ, et al. Humanin prevents age-related cognitive decline in mice and is associated with improved cognitive age in humans. Sci Rep. 2018; 8:14212. https://doi.org/10.1038/s41598-018-32616-7
Picture: https://www.orissapost.com/human-lifespan-has-no-fixed-limit/
By Jordan Lyons, PharmD candidate 2021
For full article, visit https://www.aging-us.com/article/103534/text, published online 6/23/2020