Turning Back The Clock

Chronological age is a mundane sort of measure, dependably and depressingly only ever proceeding in an upwards direction. It isn't therefore much use as an assessment tool for aging intervention within individuals. However, we previously discussed the concept of alternative biological and epigenetic measures of aging. Such epigenetic clocks could be useful for determining the extent to which any regenerative medical intervention is actually working. With a reliable enough clock (and there is copious devil in the detail), any test cohort measuring biologically younger after conclusion of a medical trial would provide a strong indicator of regenerative success. Of course, with the continuing global reverberations of Covid-19, and unwelcome signs that fears of post-pandemic excess mortality were far from baseless, the idea of interventions to make people measurably younger seems like a pipe dream, or at least a goal for the far future.

But is it?

The TRIIM study from Stanford University began in 2015 and reported in September 2019. It was by any measure a limited pilot study, recruiting only ten male test subjects. It set out to determine if an intervention of human growth hormone (HGH), metformin and DHEA could safely and meaningfully restore the aging thymus and the human immune system along with it, whilst avoiding serious HGH side effects such as diabetes or Hodgkin's Lymphoma. A while back we discussed that immunosenescence is implicated in cancer alongside various other diseases of aging, so such an intervention might be expected to have far-reaching effects. And so it appeared, with participants experiencing reductions in the inflammation marker C-reactive protein, improved kidney function and reductions in prostate specific antigen. The study considered multiple proposed biological clocks, and found subjects averaged an  eighteen-month reduction in biological age after a year of treatment - in other words, they appeared around two-and-a-half years better off for joining the trial in the first place.

Although this was only a small human trial, in the Longevity space, much excitement can be generated by slightly sprightlier mice. As a consequence such promising results spawned the larger TRIIM-X trial in short order. The new study involves more than eighty subjects across both sexes and from ages forty to eighty. Although full results will likely be some way in the future, the good news is, an update presented in August 2021 suggests that a number of benefits from the smaller trial have already been replicated. So who knows? If we can learn to trust these biological measures of age, turning back the clock might be possible after all...