There are two ways to quantify age. There’s the one way everyone is familiar with in which age is defined by the number of years we have been alive – our “chronological age.” Then there’s the way that relates to how fast our body is aging and when we can expect to see symptoms and disease associated with old age – our “biological age”. Now, thanks to science, it may be possible to turn back the clock on biological aging!
But how do we find out our biological age anyway? Scientists can work it out by measuring chemical changes to our DNA that occur with time. This means that, depending on the condition of your health, you may be younger or older than your chronological age. However, a concoction of drugs (a three-drug cocktail – including one growth hormone and two anti-diabetic drugs) has been found to be able to take, on average, 1.5 years (or 2.5 years compared to chronological age) off nine patients’ biological age during a year-long trial. The study has been published in the journal Aging Cell.
The Study
- Nine patients were put under strict orders to take one growth hormone, recombinant human growth hormone (rhGH) and two diabetes drugs – dehydroepiandrosterone (DHEA), and metformin.
- The researchers then used four epigenetic clocks (aka a biochemical test to calculate biological age) to determine the effectiveness of the drug cocktail in terms of its effects on biological aging. An epigenetic clock was originally invented to predict a person’s mortality.
The Results
- The drug cocktail was found to reversed biological aging by an average of 1.5 years, or 2.5 years compared to their chronological age (as the study took 1 year), consistently across each patient and each test.
- Blood samples provided by six patients six months after the trial showed the effects continued even though they had stopped taking the drugs.
The results were unexpected. “I’d expected to see slowing down of the clock, but not a reversal,” Steve Horvath, a geneticist at the University of California, Los Angeles, told Nature.
They were also part of a study intended to find out something else! The trial was originally designed to know if a growth hormone could safely rebuild tissue in the thymus gland, a key feature of an efficient immune system – which they found it can. They had included the antidiabetic drugs just to counteract the added risk of diabetes accrued by taking the growth hormone. Testing its effect on biological aging was like a bonus.
Conclusion
As exciting as this discovery is, the researchers make it clear that the trial was preliminary. It remains to be seen whether or not the findings can be replicated (or continued.) Furthermore, the trial was very small, involving only nine participants who were all white, male, and middle-aged (51 to 65 years old) meaning there wasn’t any diversity. It would be good to continue testing but with a variety of different ethnicities, genders, and ages to really see if, and how well it works.
Gregory Fahy, the immunologist who led the trial, believes “the drugs in the cocktail might affect biological aging separately through independent mechanisms.” That is also something to be explored in larger trials.
