Oxygen therapy could ‘halt’ Alzheimer’s
Scientists have sought a drug but the answer could be boosting oxygen flow to the brain, study finds
ALZHEIMER’S disease could be delayed or even reversed by giving oxygen therapy to patients in pressurised chambers, a study suggests.
Israeli researchers found that elderly patients with mild cognitive impairment – a forerunner to dementia – had improved memory and brain functioning following regular 90-minute sessions in a hyperbaric chamber.
The pressure change allows more oxygen to be dissolved into the tissues and mimics a state of “hypoxia”, or oxygen shortage, which is known to have regenerating effects.
In separate animal studies, the researchers also showed that the therapy can help clear away sticky amyloid plaques in the brain, which stop cells from communicating and are a major sign of Alzheimer’s disease.
The team believes that the treatment works by changing the structure of vessels in the brain so that more blood can get through.
Prof Uri Ashery, of the Sackler School of Medicine at Tel Aviv University, said: “We have discovered for the first time that hyperbaric oxygen therapy induces degradation and clearance of pre-existing amyloid plaques and the appearance of newly formed plaques.
“Elderly patients suffering from significant memory loss at baseline revealed an increase in brain blood flow and improvement in cognitive performance, demonstrating hyperbaric oxygen therapy’s potency to reverse core elements responsible for the development of Alzheimer’s disease.” Although experts said the findings needed to be replicated in a larger trial and that such therapy may be difficult to offer on a large scale, they said it could open doors to using oxygen therapy for the treatment of dementia.
“The paper presents an interesting approach, in particular reminding us of the importance of vascular factors in the development not only of vascular dementia but Alzheimer’s disease too,” said Tom Dening, professor of dementia research at Nottingham University.
Dr Richard Oakley, head of research at Alzheimer’s Society, added: “Research is essential to improve care and find new treatments for the 850,000 people in the UK with dementia today, set to reach 1.6 million by 2040.”
For decades scientists have struggled to find a drug to prevent or reverse dementia, coming up with ever-more complex molecules to try to dampen the devastating impacts.
Yet the answer may be simpler than anyone thought – oxygen. A study has shown that placing patients with Mild Cognitive Impairment (MCI) in a hyperbaric chamber boosts blood flow in the brain, flooding vessels with oxygen and improving memory, attention and processing speed.
Many people diagnosed with MCI go on to develop Alzheimer’s so it may be the first treatment that could prevent such a decline.
A therapy that could stop the disease has never been more needed. There are 850,000 people living with dementia in Britain, and the figure is expected to rise to a million by 2025.
Although the first drug for Alzheimer’s – aducanumab – was approved by the US this year, there are fears it will not live up to expectations outside clinical trials.
In contrast to a drug, hyperbaric therapy works by giving oxygen through a mask while inside a pressurised chamber. It is a high pressure environment like that used to help divers recover from the bends.
The pressure change allows more oxygen to be dissolved into the tissues and mimics a state of “hypoxia”, or oxygen shortage, which is known to have regenerating effects.
Reduced blood flow to the brain, and the decrease in oxygen that it brings, precedes the onset of dementia and the level of flow correlates with the degree of cognitive impairment in Alzheimer’s. So it makes sense to think that improving blood flow might also improve the condition.
In the study, six elderly patients were given oxygen inside a chamber for 90 minutes, five days a week over three months. The blood flow in the brain increased by 16 to 23 per cent.
At the same time, memory test scores improved by 16.5 per cent, attention by six per cent and information processing speed was boosted by 10.3 per cent.
Researchers believe that treatment not only improves levels of oxygen in the brain, but actually changes the structure of blood vessels, increasing their width and reducing wall thickness. It suggests that the beneficial effects may last for some time after the treatment.
Although the therapy has not yet been tested on patients with Alzheimer’s, when scientists tried it on mice with Alzheimer’s it reduced the number of amyloid plaques by up to 30 per cent, shrank remaining plaques by 18 per cent, and prevented the reemergence of new ones.
The sticky plaques are believed to prevent brain cells communicating and are one of the major targets in drugs for Alzheimer’s.
The mice even started building better nests after the treatment, and navigated mazes more proficiently.
Prof Uri Ashery, at Tel Aviv University, said: “We have discovered that hyperbaric oxygen therapy induces degradation and clearance of pre-existing amyloid plaques and the appearance of newly formed plaques.
“Elderly patients suffering from significant memory loss at baseline revealed an increase in brain blood flow and improvement in cognitive performance, demonstrating hyperbaric oxygen therapy potency to reverse core elements responsible for the development of Alzheimer’s.”
In 2020, the same team showed that hyperbaric therapy can reverse the ageing process, lengthening telomeres – the protective carps at the end of chromosomes – by 20 per cent.
It also cut senescent – or dormant – cells by up to 37 per cent, making way for new healthy cells to regrow.
Patients undergoing therapy have reported improved physical abilities such as having more energy, stamina and sexual performance, in men.
There is a drawback. Few hospitals are able to offer hyperbaric treatment and the current therapy comes with a gruelling timetable of sessions.
“The treatment would have to be continued indefinitely, so patients would have to be motivated and have good transport links to the treatment facility, “said Prof Tom Dening, at the University of Nottingham.
“If we consider that the number of people with dementia in the UK is approaching one million, it is hard to see how hyperbaric oxygen could ever be available on this scale.”
But it does open a new avenue for treating the disease. Oxygen delivering drugs are already in development for heart conditions. “The paper presents
‘Elderly patients with significant memory loss at baseline revealed an increase in brain blood flow and improvement in cognitive performance’
‘Vascular factors are important in development of vascular dementia and of Alzheimer’s too’
an interesting approach, in particular reminding us of the importance of vascular factors in the development not only of vascular dementia but Alzheimer’s too,” added Prof Dening.
Alzheimer’s charities said that further larger trials were needed to determine whether the treatment is effective but that therapies that prevent dementia in the first place may end up being the most useful.
Dr Susan Kohlhaas, at Alzheimer’s Research UK, said: “Many of the Alzheimer’s treatments currently being tested are drugs that target the hallmark disease proteins directly, but it’s important we maintain a broad spectrum of potential approaches.
“Larger scale clinical trials with more people are needed to ascertain whether this treatment is effective, particularly when measuring longer term benefits to memory and thinking.
“The diseases that cause dementia begin in the brain many years before symptoms like memory loss show and it’s likely for treatments to be effective at slowing down the diseases that cause dementia, they will need to be given earlier rather than later.”
The Israeli study is part of a larger research program looking to reverse aging and its accompanying ailments and the team say that further trials will take place shortly.
For now, the research is a tantalising glimpse that hope may be on the horizon for the treatment of Alzheimer’s and that it may come from the most unlikely source. The air that we breathe.