Oxygen flows through our blood and is critical for energy production in our cells, so the idea that suppressing oxygen in the body might help protect the brains of people with Parkinson’s disease may surprise you. However, a series of research projects backed by The Michael J. Fox Foundation (MJFF) shows the potential of hypoxia (oxygen deficiency) as a powerful therapy for Parkinson’s disease.
How Can Hypoxia Help?
While oxygen is essential for life, a current trial is exploring if brief, controlled periods of hypoxia may actually trigger protective responses in the brain. These responses could help slow the cell damage and death that defines Parkinson’s, potentially improving motor function and even altering the course of the disease
MJFF has previously supported research to study whether altitude can reduce symptoms for people with Parkinson’s, stemming from anecdotal reports that symptoms were reduced in high-altitude locations. Places at higher altitudes have less oxygen in the air, leading to theories about the usefulness of hypoxia.
Additional research funded by MJFF explores an intentional approach to replicating the purported benefits of altitude. Bastiaan R. Bloem, MD, PhD, and his team are exploring how intermittent hypoxia (a form of hypoxia that alternates between low-oxygen and normal-oxygen periods) can activate the body’s protective pathways. Their work will test the idea that controlled oxygen deprivation might stimulate cellular processes that protect neurons from degeneration, a breakthrough that could help preserve brain function and improve quality of life for people with Parkinson’s.
Carbon Monoxide: A Similar Pathway for Neuroprotection
In addition to intermittent hypoxia, another promising avenue that is currently in clinical testing involves carbon monoxide. Carbon monoxide actually plays an important role in normal body function but can be lethal if inhaled in large quantities. That’s why you likely have a carbon monoxide detector in your home: If your furnace or hot water heater is leaking carbon monoxide, you want to know so you can protect yourself and your family.
However, the carbon monoxide being investigated for this study is different. First, it is ingested in a liquid form, not inhaled as a gas. Second, the dose is very small — small enough to not be dangerous, and researchers theorize, just enough to protect against the cellular damage that occurs in Parkinson’s disease.
MJFF is supporting a Phase IIa clinical study from Hillhurst Biopharmaceuticals, which is investigating HBI-002, a low-dose liquid formulation of carbon monoxide for Parkinson’s. This study could provide critical insights into how carbon monoxide might help preserve brain function in Parkinson’s, offering an alternative route to neuroprotection that could complement or enhance the effects of hypoxia-based treatments.
Carbon monoxide initially captured researchers' interest in part because smoking cigarettes is associated with a reduced risk of PD, and you inhale carbon monoxide when smoking. Research published in August 2024 linked carbon monoxide levels to the reduced risk of PD among smokers, increasing interest in the potential of therapeutic carbon monoxide that could be achieved without the health risks of smoking.
Building a Path to New Treatments
Both intermittent hypoxia and carbon monoxide are at the forefront of a new wave of research exploring how the body’s natural responses to oxygen limitation can be harnessed to protect the brain. While these strategies are still in the early stages of development, they join a pipeline of promising therapies that offer real hope for improving the lives of people with Parkinson’s disease.