Aging reversal: Closer than we thought?
A Newsweek article this month discussed a recent clinical trial
which concluded that we might be moving closer toward reversing the aging
process (Lemon, 2019). The aim of this
relatively small trial, titled “Reversal of epigenetic aging and
immunosenescent trends in humans” published in Aging Cell, was to
determine whether or not using growth hormone was a safe and effective way to
restore tissue in the thymus (Fahy et al., 2019). The thymus gland, located behind the top of
the breast bone, plays an important role in immune function (our protective
shield against harmful pathogens).
The clinical trial consisted of 10 healthy men between the ages of
51 to 65 and whose participation was voluntary. However, one participant was
removed from the study due to bradycardia which started about 1 month after
enrollment. Patients were injected with
a cocktail mix consisting of recombinant growth hormone (rhGH) and two diabetes
medications (metformin and dehydroepiandrosterone (DHEA)). Growth hormone was chosen because it had been
previous shown to directly effect that thymus as well as have qualities of
restoring the immune system (Fahy et al., 2019).
Results demonstrated about a 1.5-year decrease of the epigenetic
age when compared to patients who did not undergo treatment. Specifically, the
rate of patient epigenetic (estimated biological age determined by DNA
methylation (measure by how cells are expressed)) age when compared to their
chronological age (actual age) rose from -1.6 years (from the initial 0-9
months) to -6.5 years (from 9-12 months with treatment). In other words, it was estimated that age
regression dramatically quickened with respect to the length of time they
received treatment (Fahy et al., 2019).
Although there are no other known studies to corroborated or substantiate these
results (Horvath, 2013), the researchers are optimistic that this data may be
of future significance because the study demonstrated significant results for thymic regeneration and a significant correlation between thymic fat-free factor (TFFF) (a factor associated with the accumulation of fat tissue around the thymus) and favorable changes in white blood cells of interest (monocytes and leukocytes which protect against infection and disease) (Fahy et al., 2019). In other words, this study implies an ability of the thymus to regenerate and improvement in disease risk factors (Fahy et al., 2019).
This clinical trial appears to be a good step forward in understanding the aging process, however, it does lack diversity through gender, age, and ethnicity. It would be interesting to see if there is any statistical or clinical significance if the population increase to 30+ participants and the gender is expended to include women as well as persons of different cultural ethnic background.
References:
Fahy GM, Brooke
RT, Watson JP, Good Z, Vasanawala SS, Maecker H, ... & Horvath S. (2019).
Reversal of epigenetic aging and immunosenescent trends in humans. Aging Cell, e13028.
Horvath S.
(2013). DNA methylation age of human tissues and cell types. Genome
Biol, 14(10): 3156.
Lemon, J. (2019,
September 8). Drug trial reverses patients' biological age by an average of
more than two years. Retrieved from https://www.newsweek.com/drug-trial-reverses-biological-age-average-more-two-years-1458204
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ReplyDeleteI think it would be interesting to think about the ethical implications of age reversal. The age reversal would cause profound changes to the human condition. I was reading a journal on PubMed that posed an interesting question about age reversal. The question that if we are trying to stop aging and reverse it, it is almost as if age is considered a disease (Gems, 2011). It would lead to extending life beyond its natural span which would change how the world functions socially, economically, and environmentally.
ReplyDeleteGems D. (2011). Tragedy and delight: the ethics of decelerated ageing. Philosophical transactions of the Royal Society of London. Series B, Biological sciences,
Delete366(1561), 108–112. doi:10.1098/rstb.2010.0288
Georgi,
ReplyDeleteNeat topic!! I never thought the fountain of youth would come to fruition in our lifetime! When you say reversal of epigenetic aging – are you saying someday we could press ‘restart’ on all the bad choices we made when we were young, dumb and invisible? If so, sign me up!
Advancement in the medical field concurrently breeds many ethical concerns. I can see a plethora of pros and cons to the idea of epigenetic reversal. Potential pros being, of course, bringing us that much closer to finding a 'cure' for cancer. Reversing alterations to genetic expression from exposure to teratogens may also benefit offspring making it so these epigenetic changes are not passed on. If this was the case, I wonder if epigenetic reversal could potentially knock out certain familial diseases and cancers?
The cons being that this method involves manipulation of genetic expression which is a huge controversy (as we saw with He Jiankui’s recent work). With genetic engineering there is always the caveat of trading one thing for another. For example, azacytidine is a drug used to treat Myelodysplastic syndrome that works by turning genes on that have been previously shut off by methylation (Weinhold, B, 2006). The problem with this method is that the drug also turns off/on many other genes that have subsequent effects (Weinhold, B, 2006). These secondary effects of altering genetic expression is a potential rabbit hole of unknown consequences.
My questions for you are: Did you happen to find anything during your research that mentioned this method having secondary consequences such as having effects on other genes that were outside of the target set? Also, I am just curious to know what are your personal opinions are on this topic?
Weinhold, B. (2006). Epigenetics: The Science of Change. Environmental Health Prospect, 3(114), A160–A167. https://doi.org/10.1289/ehp.114-a160