All living creatures eventually wither and die. There’s no escaping death and taxes, they say. But that doesn’t mean aging can’t be slowed down. In fact, researchers at Tel Aviv University in Israel took it a step further, showing in a new study that weekly hyperbaric oxygen sessions reversed a key process known to be involved in cellular aging.

The caps on your chromosomes

Every day, every hour, every second one of the most important events in life is going on in your body—cells are dividing. Right now as you’re reading this sentence, somewhere cells are dividing, but each replication comes at a cost.

Telomeres cap and protect the ends of chromosomes from degradation, making sure our DNA gets copied properly when cells divide. Due to the way DNA replication is performed in eukaryotic cells (that’s us!), these telomeres shorten with each cellular replication. At some point, the telomeres, which you can envision as the caps of a shoelace, shorten to a critical limit. Just like a shoelace without a cap will detangle and ruin the fabric, so will severely shortened telomeres trigger the malfunction of cellular division, also known as senescence. In time, the accumulation of these senescent cells is believed to be one of the primary causes of aging.

Studies have linked shortened telomeres not only to aging but also to cancer. As such, the processes that regulate telomeres have been targeted by all sorts of experimental therapies meant to slow down aging. Of particular interest is an enzyme called telomerase, which seems to have the ability to regenerate lost sections of the telomere — at least it does so in tissues with a high turnover of new cells, such as the lining of the gut. Some groups look at telomerase gene therapy as being primarily a form of regenerative medicine. However, these therapies haven’t been validated due to the small number of participants so far.

In Israel, researchers led by Shair Efrati, a physician from the Faculty of Medicine and Sagol School of Neuroscience at Tel Aviv University, have taken a different route towards improving telomere health. Their therapy involves breathing pure oxygen in a pressurized chamber with pressure levels 1.5 to 3 times higher than average.

The procedure, known as hyperbaric oxygen therapy (HBOT), is by no means a novelty. For over a century it has been used to treat deep-sea divers suffering from decompression sickness or people who’ve been poisoned with carbon monoxide. 

In a clinical trial, 35 healthy adults aged 64 and older spent 90 minutes in a hyperbaric oxygen chamber, which saturated their blood with oxygen. The participants repeated this experience once a week over the course of three months.

Blood samples were collected before the treatment and during the trial at one-month intervals, as well as two weeks after the trial was over. Strikingly, by the end of the trial, the participants’ telomeres not only showed no shortening, they actually extended by 20%. The participants also experienced a significant drop in the number of senescent T helper cells, showing that the extended telomeres may be reversing some aging, the authors reported in the journal Aging.

As a caveat, the study’s main limitation is its small sample size. Furthermore, the duration of the therapy’s effect has yet to be determined in long-term follow-ups. But all things considered, these are promising results, showing that a relatively straightforward and readily available form of therapy could one day partially reverse aging — and perhaps even extend our lifespans.

Until such therapy is confirmed, the best thing you can do to preserve your telomeres is to have a healthy diet and exercise regularly.