First hint that body’s ‘biological age’ can be reversed

In a small trial, drugs seemed to rejuvenate the body’s ‘epigenetic clock’, which tracks a person’s biological age.

A person’s biological age, measured by the epigenetic clock, can lag behind or exceed their chronological credit: Patrick McDermott/Getty

A small clinical study in California has suggested for the first time that it might be possible to reverse the body’s epigenetic clock, which measures a person’s biological age.

For one year, nine healthy volunteers took a cocktail of three common drugs — growth hormone and two diabetes medications — and on average shed 2.5 years of their biological ages, measured by analyzing marks on a person’s genomes. The participants’ immune systems also showed signs of rejuvenation.

The results were a surprise even to the trial organizers — but researchers caution that the findings are preliminary because the trial was small and did not include a control arm.

“I’d expected to see slowing down of the clock, but not a reversal,” says geneticist Steve Horvath at the University of California, Los Angeles, who conducted the epigenetic analysis. “That felt kind of futuristic.” The findings were published on 5 September in Aging Cell1.

“It may be that there is an effect,” says cell biologist Wolfgang Wagner at the University of Aachen in Germany. “But the results are not rock solid because the study is very small and not well controlled.”

Marks of life

“I’d expected to see slowing down of the clock, but not a reversal,” says geneticist Steve Horvath at the University of California, Los Angeles, who conducted the epigenetic analysis. “That felt kind of futuristic.” The findings were published on 5 September in Aging Cell1.

“It may be that there is an effect,” says cell biologist Wolfgang Wagner at the University of Aachen in Germany. “But the results are not rock solid because the study is very small and not well controlled.”

Marks of life

The epigenetic clock relies on the body’s epigenome, which comprises chemical modifications, such as methyl groups, that tag DNA. The pattern of these tags changes during the course of life, and tracks a person’s biological age, which can lag behind or exceed chronological age.

Scientists construct epigenetic clocks 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.

Steve Horvath, PhD

The latest trial was designed mainly to test whether growth hormone could be used safely in humans to restore tissue in the thymus gland. The gland, which is in the chest between the lungs and the breastbone, is crucial for efficient immune function. White blood cells are produced in the bone marrow and then mature inside the thymus, where they become specialized T cells that help the body to fight infections and cancers. But the gland starts to shrink after puberty and increasingly becomes clogged with fat.

Evidence from animal and some human studies shows that growth hormone stimulates regeneration of the thymus. But this hormone can also promote diabetes, so the trial included two widely used anti-diabetic drugs, dehydroepiandrosterone (DHEA) and metformin, in the treatment cocktail.

The Thymus Regeneration, Immunorestoration and Insulin Mitigation (TRIIM) trial tested 9 white men between 51 and 65 years of age. It was led by immunologist Gregory Fahy, the chief scientific officer and co-founder of Intervene Immune in Los Angeles, and was approved by the US Food and Drug Administration in May 2015. It began a few months later at Stanford Medical Center in Palo Alto, California.

Fahy’s fascination with the thymus goes back to 1986 when he read a study in which scientists transplanted growth-hormone-secreting cells into rats, apparently rejuvenating their immune systems. He was surprised that no one seemed to have followed up on the result with a clinical trial. A decade later, at age 46, he treated himself for a month with growth hormone and DHEA and found some regeneration of his own thymus.

In the TRIIM trial, the scientists took blood samples from participants during the treatment period. Tests showed that blood-cell count was rejuvenated in each of the participants. The researchers also used magnetic resonance imaging (MRI) to determine the composition of the thymus at the start and end of the study. They found that in seven participants, accumulated fat had been replaced with regenerated thymus tissue.

All of this work required the collaboration of many disciplines, genetics, statistics, biochemistry, immunology, and mathematics.

While the clinical evidence is still limited by the small size of the trial, the science is real. Perhaps soon there will be a test to measure your biological clock.

Rather than being viewed as a fountain of youth, there are other important motivating factors to research anti-aging. Source:  Reversal of epigenetic aging and immunosenescent trends in humans Population aging is an increasingly important problem in developed countries, bringing with it a host of medical, social, economic, political, and psychological problems

The first hint that body’s ‘biological age’ can be reversed: In a small trial, a cocktail of drugs seemed to rejuvenate the body’s ‘epigenetic clock’.