Key to longevity? Breathe LESS oxygen, says study

Many believe that restricting how much they eat or exercising obsessively can extend their lifespan.

But scientists at Massachusetts General Hospital have now suggested a third way; take less oxygen.

In a study with mice, they found that rodents kept at 11 percent oxygen, equivalent to Mount Everest Base Camp, lived 50 percent longer than those kept at ambient levels.

They said breathing less oxygen could reduce damage to cells and encourage them to clean and recycle damaged parts, which slows down the aging process.

It wasn’t clear if the study results could be replicated in humans, but previous papers have suggested that humans living at higher altitudes live longer than their peers. But they are also at higher risk of low birth weight and stunted growth, which scientists say may be due to a lack of oxygen.

In the study, the first to examine oxygen restriction in mice, the researchers used rodents that had been bred to age rapidly.

They were divided into two groups at four weeks of age, with half remaining at ambient oxygen levels (21 percent) while the rest were placed in a chamber that reduced levels to 11 percent.

Each was offered adequate food and water, and the scientists monitored the mice until death.

The results showed that the mice living at ambient oxygen levels lived a total of 15.7 weeks on average.

But those who were exposed to restricted oxygen levels lived almost eight weeks longer, with a life expectancy of 23.6 weeks.

Mice in both groups ate roughly the same amount of food.

The results support previous research, which also found that oxygen restriction prolongs the lifespan of yeast, worms, and fruit flies.

The researchers now hope to further test oxygen restriction and longevity to support their findings, possibly in other animals.

It was unclear how humans could be continuously exposed to lower levels of oxygen to help extend their lifespans.

But in addition to spending several hours a day in a low-oxygen chamber, the paper also pointed to how people who live at higher altitudes live longer.

However, other papers have warned that people born at these higher levels may have lower birth weights and stunted growth due to lack of oxygen.

Dr Roger Roberts, a pulmonologist who led the study, told DailyMail.com: “It is premature to speculate on the implication of these findings for human ageing.”

“But there are several exciting clues from epidemiological research that living at high altitudes where there is a lower oxygen concentration could increase average life expectancy and reduce the burden of age-related diseases.”

The researchers suggested that oxygen restriction may slow aging because it triggers a pathway in cells that causes damaged parts to be removed and recycled more frequently.

They also suggested that cells faced less damage from oxidative stress, or the molecules released when oxygen is used as energy that can damage DNA.

They also suggested that there was a reduction in the levels of neurodegeneration and inflammation in the body.

Limitations of the study include that it was conducted in mice rather than humans and that low oxygen exposure from an early age may be necessary to trigger the effects.

Dr. Roberts and others said in the article: “Epidemiological evidence suggests that lifelong oxygen restriction could slow the aging process in humans.

“Although there are many potential confounders for this finding, recent cross-sectional studies in Bolivia have shown significant enrichment for nonagenarians and centenarians at very high altitudes.

“There is also data to suggest that there are potential benefits of moving to altitude in adulthood.”

Previous research has suggested that people living at high altitudes live longer than their peers living at sea level.

One paper found that of the 20 counties with the highest life expectancy in the US, 11 for men and five for women were located at about 5,900 feet above sea level.

The researchers previously suggested that a chronic lack of oxygen triggers pathways in cells that cause them to repair damage, reducing age-related decline.

Other methods to slow the rate of aging that have been suggested include eating less food.

Primate research on this method has been inconclusive, but some human studies suggest it may increase lifespan.

Another prominent method is getting adequate exercise, with physical activity associated with a wide range of health benefits, including better blood sugar control and reduced risk of many chronic diseases.

But studies have also warned that obsessive exercise (doing more than five hours a week of vigorous cardio and not resting at least one day a week) can actually have the opposite effect and shorten life expectancy.

They say this is because it increases the risk of joint and heart problems that could lead to an earlier death.

The latest article on chronic oxygen restriction in mice was published in the journal PLOS Biology.