Any consideration of treating aging as a medical condition should primarily focus on the few true rejuvenation therapies that are now arriving at the point of clinical trials or availability via medical tourism. This became a topic worth keeping an eye on in 2017 with the commencement of the first formal human trials of senolytic therapies - as well as a fair amount of quiet, unofficial self-experimentation. This and other classes of treatment noted here will typically directly address the low-level cell and tissue damage that causes aging, following the SENS vision for rejuvenation through repair. The goal, the point of interest, is to turn back aging by reversing its causes.
- Caveat Emptor: Most Potential Therapies for Aging are Marginal at Best
- Senolytic Drug Candidate Trials
- Amyloid Clearance Trials
- Considering Stem Cell Therapies
Bear in mind that true rejuvenation therapies, those that are based on repair of the cell and tissue damage that causes aging, and thus capable in principle of producing sizable benefits for old people, are still a minority concern in the field of aging research. Most of the new potential therapies declared by one or another authority to be a means to treat aging are marginal at best. These are pharmacological approaches that tinker with the operation of metabolism to modestly slow markers of aging, and will not be included here. Examples include the TAME metformin trial, as well as tests of rapamycin, nicotinamide riboside, and the like. The results in humans from these therapies seem likely to be smaller and less reliable than those produced through exercise or the practice of calorie restriction - and more to the point, these are only ways to slow aging, not to turn back its causes in order to produce actual rejuvenation.
The first accessible human trials for senolytic drug candidates capable of selectively destroying senescent cells are underway. Some of these can be discovered via ClinicalTrials.gov by searching for suitable terms, such as "senolytic", or the names of relevant drug candidates. Using "senescent cells" as a search term will likely pull in too many unrelated cancer and obesity studies, swamping the useful results. Small pilot trials of senolytic drug candidates are being conducted by the Betterhumans non-profit organization, several research centers including the Mayo Clinic, and also by biotech companies such as Unity Biotechnology. These are initially focused on individuals 65 and over with specific conditions strongly linked to senescent cells in animal studies, such as osteoarthritis, metabolic syndrome, and fibrotic kidney disease.
Amyloids are one of the distinguishing marks of old tissues, are created as a side-effect of the normal operation of metabolism, and so should be removed. Numerous attempts to clear amyloid-β in patients with Alzheimer's disease have been made, most via immunotherapy. Until very recently, success was elusive. Search ClinicalTrials.gov to see the scope of this effort. Trials are only open to patients suffering from later stages of Alzheimer's disease, and until the expectation of benefits is improved and the risk inherent in this class of therapy is greatly reduced, this isn't about to blossom into greater availability.
Separately, progress has been made in clearance of transthyretin amyloid, associated with heart failure. A few approaches, such as SAP antibodies and CPHPC have shown promise in human trials. These are ongoing, organized by GSK, but only open to a small number of patients with significant levels of amyloidosis.
Do currently available stem cell therapies produce rejuvenation? This can be debated. The most commonly used stem cell therapies, such those involving mesenchymal stem cells that are widely available in clinics and via medical tourism, fairly reliably produce reductions in chronic inflammation for some period of time, but little more than that. More specialized therapies that might be argued to carry out repairs are far less readily available, and there is decidedly mixed evidence for any specific approach to in fact meaningfully and reliably address causes of aging. There is clearly a bright future for this field, but most of the promised gains have yet to materialize.
Last updated: May 27th 2019