Can we reverse our biological age? The usual media hysteria...

I must have seen at least 10 of my media inputs hyping a small study by Fahy et al. (9 white men, and lacking controls) pointed to by Abbott suggesting that the body's epigenetic clock might be reversed. The study actually had the goal of seeing whether human growth hormone could stimulates regeneration of the thymus gland and enhance immune function. Because the hormone can promote diabetes, the trial included two widely used anti-diabetic drugs, dehydroepiandrosterone (DHEA) and metformin, in the treatment cocktail. (Metformin is being evaluated as an anti-aging drug in several large scale studies).

Checking the effect of the drugs on the participants’ epigenetic clocks was an afterthought. The clinical study had finished when Fahy approached Horvath to conduct an analysis. (Epigenetic clocks are constructed by selecting sets of DNA-methylation sites across the genome. In the past few years, Horvath — a pioneer in epigenetic-clock research — has developed some of the most accurate ones)...Horvath used four different epigenetic clocks to assess each patient’s biological age, and he found significant reversal for each trial participant in all of the tests. “This told me that the biological effect of the treatment was robust,” he says. What’s more, the effect persisted in the six participants who provided a final blood sample six months after stopping the trial, he says.

The understandable excitement over this result is probably out of proportion to the probability it will be confirmed in larger experiments with proper controls.