Here we've gathered published studies on HBOT in aging, skin, performance, cognition, pain, and wound healing. Each card shows the main finding, who conducted the study, and how strong the evidence is. Click through to the original publication if you want to read it in full.
Thirty-five adults over 64 underwent 60 treatments over three months. Telomeres in several types of immune cells were afterward between 20 and 38 percent longer. No other treatment was given. The study lacked a control group.
In the same group, the proportion of senescent T-helper cells decreased by 37 percent. Senescent cells stop dividing but continue emitting inflammatory signals, and are considered one of the drivers behind biological aging.
After 20 treatments, the number of circulating CD34-positive stem cells had increased eightfold in healthy participants. The body mobilized them on its own, without external supplementation. Small study, no clinical outcomes were measured.
Seventy healthy adults over 64 received 60 treatments. Skin biopsies showed 13 percent higher collagen density afterward. Collagen is the protein that gives skin its elasticity and firmness, and the amount naturally decreases with age.
In the same skin biopsies, elastic fibers had more than doubled in length. At the same time, the number of senescent cells in the skin decreased. The result is histological, meaning measured in the tissue rather than assessed by appearance.
In a double-blind study with 31 trained individuals aged 40 to 50, VO2max increased by 4.3 percent after 40 treatments over two months. The control group received sham treatment. The effect therefore requires a full program, not individual sessions.
The same study measured oxygen uptake at the anaerobic threshold, the intensity at which the body starts producing lactic acid faster than it is broken down. That value rose by just under 11 percent in the treatment group.
Muscle biopsies from the same participants showed a 17 percent increase in mitochondrial content, while the control group lost just under 9 percent. Mitochondria are the cells' energy production. The sample here is only 22 people.
Twenty young elite football players received either one treatment session or sham treatment immediately after a match. Muscle damage markers and performance tests did not differ at all between the groups. Only perceived fatigue was lower one hour afterward. We include this one because it points in the other direction.
Sixty-three healthy adults over 64 were randomized to 60 treatments or a waitlist. Attention and concentration improved clearly in the treatment group. The effect size of 0.75 is considered medium to large.
The same study also measured how quickly the brain processes information. There too, the treatment group pulled ahead. Brain imaging showed increased blood flow in the areas associated with those specific abilities.
Seventy-four patients with persistent deficits six months to three years after stroke received 40 treatments. Neurologycal function and quality of life improved, and SPECT imaging showed increased activity in tissue previously considered lost.
Fifty-six people with persistent symptoms one to five years after a mild brain injury received 40 treatments in a crossover study design. Memory, attention, and quality of life improved in both groups once they received treatment.
Women with fibromyalgia received 40 treatments. Pain level, tender points, and quality of life improved, and brain imaging showed altered activity in pain-regulating regions. Small study with a crossover design and a high risk of placebo effect.
Patients with interstitial cystitis, meaning chronic bladder pain without infection, were randomized to treatment or sham treatment. The treatment group reported greater relief from pain and urgency. Few participants, so the result needs to be replicated.
In a randomized study from Lund, 94 patients with hard-to-heal foot ulcers received either oxygen therapy or sham treatment on top of standard wound care. After one year, 52 percent of the wounds were fully healed in the treatment group versus 29 percent in the control group.
Cochrane's systematic review found that the treatment improves short-term healing of diabetic wounds. The review also notes that several of the studies are small and methodologically weak, and a later Canadian study found no effect at all.
In a study published in the New England Journal of Medicine, 152 patients with carbon monoxide poisoning were randomized to hyperbaric or normobaric oxygen. After six weeks, 25 percent in the hyperbaric group had cognitive sequelae versus 46 percent in the control group.
Cochrane's review of randomized trials showed that treatment initiated early for sudden sensorineural hearing loss produces greater hearing improvement than usual care. The long-term effect remains unclear.
RICH-ART was a randomized study from Sahlgrenska in which patients with bladder problems after pelvic radiation therapy received 30 to 40 treatments. The treatment group had greater improvement in urinary symptoms than the control group.
Combat veterans with PTSD who had not responded to either talk therapy or medication were randomized to treatment or control. The treatment group had clearly reduced symptoms, and MRI showed changes in the brain's white matter and functional connectivity.
Seventy-three patients with persistent cognitive symptoms after COVID-19 were randomized to 40 treatments or sham treatment. The treatment group improved in attention and executive function, with corresponding changes visible on MRI.
In the same study, self-rated physical quality of life, energy levels, and sleep also improved. Follow-up extended only to shortly after the treatment period, so how long the effect lasts is not known.
In a small blinded pilot study, patients admitted for moderate to severe ulcerative colitis flares received treatment alongside standard care. More reached remission than in the control group. The evidence base is too small to draw conclusions about clinical benefit.
No studies in this category yet.