Key to longevity? Breathe LESS oxygen, says study

Many believe that limiting how much they eat or obsessive exercise can extend their lifespan.

But scientists at Massachusetts General Hospital have now proposed a third way; absorb less oxygen.

In a study on mice, they found that rodents kept on 11 percent oxygen — equivalent to Mount Everest’s base camp — lived 50 percent longer than those at the ambient level.

They said that breathing in less oxygen can reduce damage to cells and prompt them to clean up and recycle damaged parts, slowing down the aging process.

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

In the study, the first to examine oxygen restriction in mice, the researchers used rodents bred to age quickly.

They were split 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 raised the level to 11 percent.

Each was offered plenty of food and water, and scientists then followed the mice to their deaths.

The results showed that mice living at ambient oxygen levels lived an average of 15.7 weeks overall.

But those exposed to limited oxygen levels lived nearly eight weeks longer — with a lifespan of 23.6 weeks.

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

The results support previous research, which also showed that oxygen restriction extends the lifespan of yeasts, worms and fruit flies.

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

It was not clear how people could be continuously exposed to lower oxygen levels to extend their lifespan.

But in addition to spending several hours a day in a room with little oxygen, the paper also pointed out that 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 oxygen deprivation.

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

“But there are several interesting indications from epidemiological research that living at high altitudes with lower oxygen concentrations can extend median lifespan and reduce the burden of age-related diseases.”

The researchers suggested that oxygen restriction may slow aging because it activates a pathway in cells that makes them more likely to clean up and recycle damaged parts.

They also suggested that cells suffered 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 neurodegeneration and inflammation levels in the body.

Limitations of the study include that it was conducted in mice rather than humans and that low oxygen exposure from a young age may be required to produce the effects.

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

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

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

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

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

Researchers have previously suggested that a chronic lack of oxygen activates pathways in cells that cause them to repair damage, reducing age-related decline.

Other methods that have been suggested to reduce the rate of aging include consuming less food.

Research in primates on this method has been inconclusive, but some human studies suggest it may have the potential to increase life expectancy.

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

But studies have also warned that obsessive exercise — doing vigorous cardiovascular exercise for more than five hours a week and not getting at least one rest day a week — may actually have the opposite effect and shorten lifespan.

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

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