Could oxygen therapy reverse Alzheimer’s disease?

The study, which combined the use of HBOT in the treatment of animals genetically engineered to develop Alzheimer’s and a group of individuals over the age of 65 who were already having memory loss.

 Study results show elevated blood flow and improved oxygenation in the brain of patients suffering from cognitive impairment (photo credit: Aging/Uri Ashery)
Study results show elevated blood flow and improved oxygenation in the brain of patients suffering from cognitive impairment
(photo credit: Aging/Uri Ashery)

For the first time, a non-pharmaceutical clinical trial has proven effective in reversing the main activators of Alzheimer’s disease, according to Tel Aviv University’s Prof. Shai Efrati, whose study on the use of hyperbaric oxygen therapy (HBOT) to improve brain function was published Thursday in the peer-reviewed medical journal Aging.

The study, which combined use of HBOT in the treatment of animals genetically engineered to develop Alzheimer’s and a group of individuals over the age of 65 who were already experiencing memory decline – the stage before Alzheimer’s – yielded several positive results. These included improvement in vascular function, of blood flow to the brain, memory capacity, attention and information processing speed, as well as a drop in brain amyloid load.

Amyloids are non-soluble proteins. Amyloid beta deposits in the brain’s blood vessel walls are the most common vascular pathology in Alzheimer’s.

“The therapy triggers our body to do the repairs that are needed to reverse the process that culminates in Alzheimer’s disease,” Efrati told The Jerusalem Post.

A press release by Tel Aviv University explained, “Hyperbaric medicine is a form of therapy that requires patients to be kept in special chambers in which the atmospheric pressure is much higher than that normally experienced at sea level. In addition, they breathe air composed of 100% oxygen.”

 Prof. Uri Ashery (credit: Aging/Uri Ashery)
Prof. Uri Ashery (credit: Aging/Uri Ashery)

The treatment is already used for other indications and is known to be relatively safe when managed by a medical professional. A previous study by Efrati and a team from Shamir Medical Center in November found that when healthy adults over the age of 64 were placed in a pressurized chamber and given pure oxygen for 90 minutes a day, five days a week for three months, not only was the aging process delayed – it was actually reversed.

This study was carried out in two stages. First, mice were exposed to HBOT and then investigated using two-photon live animal imaging. Through examination of the mice’s brain tissues, “it was proven conclusively... that a certain therapeutic protocol brings about an improvement in vascular function and the creation of new blood vessels,” the release said. “It also prevents the deposit of new amyloid plaques on the brain cells and even leads to the removal of existing amyloid plaque deposits.”

The positive results on the mouse models were discovered in correlation to the findings of the treatment on people over 65 with cognitive decline. The therapy included a series of 60 sessions of HBOT in pressure chambers over a period of 90 days.

Efrati described the process as having participants sit in a chamber that looks like an airplane with an oxygen mask. In the chamber, the individuals were administered HBOT utilizing 100% oxygen in an environmental pressure higher than one absolute atmosphere to enhance the amount of oxygen dissolved in the body’s tissues.

AT A CERTAIN point, the participants were asked to remove their masks, bringing their oxygen back to normal levels. However, during this period, researchers saw that fluctuations in the free oxygen concentration were interpreted at the cellular level as a lack of oxygen – rather than interpreting the absolute level of oxygen.

 Prof. Shai Efrati. (credit: Courtesy of Tel Aviv University)
Prof. Shai Efrati. (credit: Courtesy of Tel Aviv University)

In other words, repeated intermittent hyperoxic (increased oxygen level) exposures induced many of the mediators and cellular mechanisms that are usually induced during hypoxia (decreased oxygen levels) – something Efrati explained is called the hyperoxic-hypoxic paradox.

The effects of the therapy on the brain were evaluated using a high-resolution perfusion MRI.

The results: 16%-23% increase in cerebral blood flow, 16.5% improved memory, and improvements in both attention and information processing speed.

“After a series of hyperbaric treatments, elderly patients who were already suffering from memory loss showed an improvement of blood flow to the brain, as well as a real improvement in cognitive performance,” said Prof. Uri Ashery, also from Tel Aviv University, who helped with the study. “Consequently, we succeeded in demonstrating the latent potential of hyperbaric medicine for treatment of neurologic conditions that originate from hypoxia – that is to say, a deficiency of oxygen reaching the cells”.

Another member of the Tel Aviv research team, Dr. Ronit Shapira, said, “The combination of an animal model from which we could learn the pathology of the disease, together with existing and available therapy, raises the hope that we will now be able to fight one of the greatest challenges to the Western world. According to our findings, hyperbaric therapy given at a young age is likely to prevent this severe disease entirely.”

 Dr. Pablo Blinder (credit: Courtesy of Tel Aviv University)
Dr. Pablo Blinder (credit: Courtesy of Tel Aviv University)

Efrati explained that until now it was thought that amyloid deposits were the primary cause of Alzheimer’s disease, but now it is understood that amyloids are just a “biomarker of the disease,” and the primary cause is related to vascular damage.

“By treating the root problem that causes cognitive deterioration with age, we are in fact mapping out the way to prevention,” Efrati said. “It is likely that hyperbaric medicine can potentially provide the opportunity for living with good brain function without relating to chronological age. The idea is to commence therapy before the onset of clinical symptoms of dementia and before deterioration and loss of extensive brain tissue. This is the stage at which blood vessels become occluded and the blood flow and the oxygen supply to the brain are diminished – a phenomenon that can already take place at a relatively early age.”

How early?

“This is still an open issue,” Efrati said, adding that the study is part of a long-term and comprehensive research program and that he hopes more answers will come soon.

  Dr. Ronit Shapira (credit: Courtesy of Tel Aviv University)
Dr. Ronit Shapira (credit: Courtesy of Tel Aviv University)