A strange throughline that biologists see among the different species of the world is that animals that tend to require fewer breaths per minute live longer. Tortoises can live up to 150 years, and only take three or four breaths a minute. By contrast, humans 12 to 16 breaths per minute, and the average American has an average lifespan between 76 and 77 years.
So in the quest to hack our bodies to make them live longer, many people are starting to tout the effects of oxygen restriction—better known as hypoxia—as a potential solution. While this has been mostly relegated to new age circles, clinical researchers are finally starting to take these investigations into the lab. With the effects of calorie restriction on increased lifespan well documented by new research these days, scientists are eager to see if other limitations actually end up boosting longevity as well.
Scientists at Harvard Medical School and Massachusetts General Hospital in Boston have published what seems to be the first ever study that demonstrates how hypoxia can lead to long lifespans in mammals. The new findings were published Tuesday in PLOS Biology.
“We have long been excited by the possibility that hypoxia could be beneficial and wanted to rigorously test this hypothesis,” Robert Rogers, a researcher at Massachusetts General Hospital and co-author of the new study, told The Daily Beast. “But we had no assumptions that it would actually work.”
The study builds off previous research led by co-author Vamsi Mootha, a molecular biologist at Harvard Medical School, who had been studying the effects of oxygen restriction in mice for over a decade. Ambient oxygen levels for most life on Earth is around 21 percent. Mootha’s lab first found that restricting oxygen to about 11 percent helped extend lifespan and delayed degeneration of brain cells in mice afflicted by Leigh syndrome (a severe neurological disorder) in 2016, and in mice afflicted by Friedreich’s ataxia (a genetic disorder affecting the nerves) in 2019.
Based on those observations as well as what’s been observed in more primitive organisms like yeast and roundworms, the team wanted to see what chronic hypoxia could do for healthy mammals.
As part of the study, Rogers, Mootha, and their colleagues bred mice in environments of normal oxygen levels (21 percent), and compared their lifespans to mice who at 4 weeks of age were moved to environments with reduced oxygen (about 11 percent—similar to an altitude of about a little over 3 miles).
The mice in reduced oxygen environments lived a whopping 50 percent longer, with media lifespans of 23.6 weeks compared to the other cohort’s 15.7 weeks. In addition, hypoxia seemed to also delay the onset of age-associated neurological impairments.
“At present we do not know the mechanism by which hypoxia extends lifespan in these mice,” Rogers admitted. Though caloric restriction has a longer body of research behind it, oxygen restriction is still a new space, and more research will be necessary to really pinpoint the mechanisms that allow hypoxia to increase lifespan in animals. In fact, what probably ends up coming out from these investigations will be a better sense of how to emulate what happens in the body in order to increase healthy aging—and not a straight up prescription to hook people up to tanks of reduced oxygen.
Moreover, Rogers cautioned against trying to speculate what the results could mean for human aging. He did highlight an interesting tidbit of research from the 1960s and 70s, when Indian Army soldiers assigned to serve three years at altitudes higher than three miles saw decreased incidence of age-related diseases like diabetes and heart disease. So the new findings seem to fall in line with the little we’ve observed in humans so far. “We view this initial report as laying the foundation for this important line of future research,” said Rogers.
That doesn’t mean you should start looking for ways to take in more oxygen in a foolish attempt to live longer. Oxygen is essential to survival, and deprivation can do incredible damage to the body and its organs—often permanently. So leave the lifespan hacks to the researchers for now.