October 22, 2019

Results from research funded in part by Life Extension® reveal a reversal of biological age and indications of rejuvenation of immune function among men who received human growth hormone and the hormone dehydroepiandrosterone (DHEA), both of which decline during aging, plus the drug metformin. The findings were reported on September 8, 2019, in the journal Aging Cell.

“We conducted what may be the first human clinical trial designed to reverse aspects of human aging, the TRIIM (Thymus Regeneration, Immunorestoration, and Insulin Mitigation) trial, in 2015–2017,” Gregory M. Fahy, PhD, and colleagues announce. “The purpose of the TRIIM trial was to investigate the possibility of using recombinant human growth hormone (rhGH) to prevent or reverse signs of immunosenescence in a population of 51‐ to 65‐year‐old putatively healthy men.”

The study sought to evaluate the effect of growth hormone replacement on immune function based on evidence of the hormone’s ability to regenerate the thymus gland, which supports immune function and degenerates during aging. Because growth hormone can increase blood glucose, the regimen included the antidiabetic drug metformin, and DHEA, which has been observed to have glucose-regulating effects.

Biological age, as assessed by various markers, can differ from chronologic age, which is measured by the number of years survived. Four epigenetic clocks that track biological age were evaluated before and after the treatment period by geneticist Steven Horvath of the University of California, Los Angeles. On average, participants’ biological age was reversed by 1.5 years in association with growth hormone therapy. “I’d expected to see slowing down of the clock, but not a reversal,” Dr. Horvath commented in a news item published in the journal Nature. “That felt kind of futuristic.”

Blood levels of immune cells also improved following treatment. Magnetic resonance imaging (MRI) revealed that fat that had accumulated in the thymus glands of seven men had been replaced with regenerated tissue.

The authors remark that while the trial was designed to investigate the possibility of thymus regeneration and reversal of immune system aging, their results “support the feasibility of this goal but unexpectedly also bring to light robust evidence that regression of multiple aspects and biomarkers of aging is possible in man.”

They conclude, “Although much more remains to be done, the general prospects for meaningful amelioration of human aging appear to be remarkably promising.”