A year-long clinical study in California suggests biological aging might not be unstoppable and that it might be possible to reverse our "epigenetic clock," which measures our biological age.

An epigenetic clock is a biochemical test that can be used to measure age. This test is based on DNA methylation levels. Biological age is how old a person seems as opposed to chronological age, which is the number of years a person has lived.

Results of the small clinical trial, recently published in the journal Aging Cell, reported nine participants took three common medications and reversed their biological age by 2 years and a half on average. These three FDA-approved medications consisted of the recombinant human growth hormone (rhGH) and two diabetes medications: dehydroepiandrosterone (DHEA) and metformin.

The objective of the trial was to regenerate the thymus, which is the “master gland of the immune system.” The thymus takes white blood cells from bone marrow and converts them into T-cells.

These key cells fight off diseases, including viruses, bacteria, and cancer. Humans, however, begin to lose this capability to manufacture T-cells by the time they reach puberty.

This research proves the concept biological aging may not be unstoppable, according to Dr. Greg Fahy, PhD, lead author of the study and chief science officer of anti-aging therapeutics company Intervene Immune.

“One of the lessons that we can draw from the study is that aging is not necessarily something that is beyond our control,” Dr. Fahy said. “In fact it seems that aging is largely controlled by biological processes that we may be able to influence.”

Epigenetic age is measured by looking at epigenetic markers indicating chemical changes to DNA over time. These markers are like “decorations on your DNA,” Dr. Fahy said.

One marker is the addition of methyl groups to DNA in a process called methylation. A relationship between aging and methylation was shown in an analysis of clinical data in a previous study led by Dr. Steve Horvath, PhD, a professor at the University of California. Dr. Horvath found methylation process to be a key metric in developing epigenetic clocks.

Epigenetic clocks can be “a beautiful tool for people who want to study changing aging,” Dr. Fahy noted.

In the past, conducting a trial to determine how a therapy affects lifespan required following the person until his death. These answers can be obtained much sooner using epigenetic clocks.

“If this really all works, and we can show it’s really as safe as we believe it is, this is something that can be used to treat aging very soon,” Dr. Fahy pointed out.

“I’d expected to see slowing down of the clock, but not a reversal,” Dr. Horvath said. “That felt kind of futuristic.”

Improving one's sense of control over life and exercising more can help lower their subjective age, studies found. Matthew Bennett/Unsplash