Getting high on their own supply

What makes the Sherpa people, who have lived in the Himalayas for thousands of years, so well-adapted to the high-altitude life, able to function on oxygen levels that incapacitate or even kill others, has inspired plenty of investigation.

Past studies point to them having fewer red blood cells buthigher levels of nitric oxide, which open up arteries and keep blood flowing. It turns out, though, that genetic adaptation to a low-oxygen environment affects their whole metabolism.

The finding comes from research by scientists from the University of Cambridge monitoring Sherpas and “lowlanders” as they climbed to Everest Base Camp, 5,300 metres above sea level.

For most people hypobaric hypoxia (insufficient supply of oxygen due to low air pressure) sets in at about 3,000 metres. The peak of Everest is 8,848 metres, and anywhere above 8,000 metres is known as “the death zone”.

Using molecular, biochemical, physiological and genetic approaches to study the two groups, the researchers found that Sherpas demonstrated a lower capacity for fatty acid oxidation in skeletal muscles, along with more efficient use of oxygen, improved muscle energetics, and protection against oxidative stress.

These metabolic adaptations, the researchers write in the journal Proceedings of the National Academy of Science, appear to be related to an enriched gene known as the peroxisome proliferator-activated receptor A (PPARA).