Scientists may have discovered an unusual way to fight Alzheimer’s disease. Instead of a pill or injection, the treatment is a gas called xenon. Researchers at Brigham and Women’s Hospital in Boston, working with Washington University School of Medicine in St. Louis, are preparing to test xenon in humans after promising results in animal studies.
Alzheimer’s affects more than 6 million Americans and has no cure. Current treatments focus mostly on removing amyloid plaques or tau tangles from the brain, but they have offered only modest improvements. This new direction looks to xenon, a colorless and odorless gas already used in anesthesia and other medical applications, as a potential way to protect brain function.
How the study was conducted
In experiments led by neuroscientist Oleg Butovsky, mice with Alzheimer’s-like conditions inhaled xenon inside a custom chamber. The gas was able to cross the blood-brain barrier, something many experimental drugs fail to do. Once inside the brain, xenon affected microglia, which are the immune cells that act as first responders against damage and infection.
Normally, microglia dysfunction contributes to brain inflammation and the buildup of amyloid plaques. But after xenon exposure, the mice had reduced inflammation, less brain atrophy, and healthier microglial activity. They also performed better at nest-building, a behavioral test linked to cognitive ability in rodents.
The results and statistics
The studies showed consistent protective effects in different mouse models, including ones that mimic amyloid plaque buildup and others that mimic tau tangles. In both cases, xenon reduced brain cell loss and improved overall brain function. The research team described xenon as shifting microglia into a state that both suppressed harmful inflammation and encouraged cleanup of damaging plaques.
One of the greatest challenges in Alzheimer’s research is finding treatments that can cross the blood-brain barrier. According to Butovsky, xenon’s ability to do this is key. It is also not a completely unknown substance. Doctors have used it as an anesthetic and even mountain climbers have used it to boost red blood cell production. This background makes it easier to study its safety in humans.
Dr. David Holtzman of Washington University explained that xenon showed benefits in both amyloid and tau models, which suggests it might be broadly effective, not just limited to one pathway of the disease.
A phase 1 clinical trial at Brigham and Women’s Hospital is set to begin in early 2025. At first, the trial will enroll only healthy volunteers in order to test safety and dosage levels. If results are encouraging, later trials will expand to people with Alzheimer’s disease.
The researchers are also exploring whether xenon could help with other conditions that involve neurodegeneration, such as multiple sclerosis, ALS, or eye diseases that cause vision loss. Work is also underway on new technologies to make xenon more efficient and possibly recyclable, since it is a rare and expensive gas.
Experts describe this research as exciting and highly unusual. Butovsky called it “a very novel discovery showing that simply inhaling an inert gas can have such a profound neuroprotective effect.” Howard Weiner, who will lead the clinical trial, said that if the human trials succeed, xenon “could open the door to new treatments for helping patients with neurologic diseases.”
Still, there are cautions. The findings so far come only from mouse studies. Many experimental treatments that look promising in animals do not work as well in humans. Researchers and families alike will be waiting closely to see if xenon can move from an experimental idea to a real-world therapy.
