Is rejuvenation of the thymus a key to restoring youth? Maybe it is.
A very surprising result appeared last week in a journal called Aging Cell. A team of scientists published the first results of a study that showed, in a small group of older men, that some signs of aging could be reversed with a 3-drug combination.
Not just slowed down. Reversed.
If this holds up, it could literally be life-changing for millions of people. I was initially very skeptical, having read countless claims of anti-aging treatments over the years, virtually all of which turned out to be wrong. Anti-aging treatments are a huge commercial market, full of misleading promises and vague claims. Youth-restoring skin treatments (which don't work) are a particular favorite of cosmetics companies.
But this new study is different. The scientists decided to explore whether recombinant human growth hormone (rhGH) could help to restore the thymus gland. Your thymus is in the middle of your chest, and it is part of your immune system, helping to produce the T cells that fight off infections. As we age, the thymus shrinks and starts to get "clogged with fat," as a news story in Nature put it. Hints that rhGH could help restore the thymus goes back decades, but it had never before been tested in humans.
The scientists leading the study added two more drugs, DHEA and metformin, because rhGH does carry some increased risk of diabetes. Both of these drugs help to prevent diabetes, and both might also have anti-aging benefits, although neither of them is known to affect the thymus.
Amazingly, in 7 out of 9 men in the study (it was a very small study), the thymus showed clear signs of aging reversal, with new thymus tissue replacing fat. The side effects of rhGH are very mild, and none of the men in this study had any significant problems from it or from the other two drugs.
Equally remarkable was another, unanticipated, sign of anti-aging. The study measured "epigenetic age" in all the subjects by four different methods. "Epigenetic age" refers to markers at the cellular level that change as we age, and as the study explains:
"Although epigenetic age does not measure all features of aging and is not synonymous with aging itself, it is the most accurate measure of biological age and age‐related disease risk available today."
After 9 months of treatment, the epigenetic age of the men in this study was 2.5 years younger. The treatment didn't just slow aging–it reversed it. The effects persisted in a followup 6 months later: one and a half years after the study began, the men's epigenetic age was 1.5 years younger than at the beginning. This is truly remarkable.
Any study has limitations, so I should mention a couple here. First, the study was very small, just 9 men, but the effects were strong and significant. Second, the lead scientist of the study, Gregory Fahy, is the co-founder of a company called Intervene Immune that plans to market anti-aging treatments. The authors also include scientists from Stanford, UCLA, and the University of British Columbia.
A few years ago I wrote about another drug combination, dasatinib and quercetin, which showed great promise in reversing aging, but only in mice. We're still waiting to hear more about that treatment, although a test in humans showed some promise earlier this year.
The new 3-drug combination is the most promising I've seen yet. The possible benefits are enormous: as the study points out, they include lower risks for at least 8 types of cancer, heart disease, and stroke. Unlike many other anti-aging treatments, this one has genuine plausibility, and the effects on the thymus can be measured almost immediately. Let's hope this one works out; we'll all be better off if it does.
