'Tibetans thrive at high altitudes due to genetic variations'

Tibetans can adapt to high altitude living due to genetic variations that allow them to maintain low red blood cell levels in environments with thin air, researchers have found in a new study.
The study conducted by Chinese researchers, however, suggested that there might be a limit to the altitude at which Tibetans can live without incurring grave health complications - 4,500 meters.
According to the study led by Tibet University Professor Cui Chaoying and two research teams, the gene variants discovered seem to cease to be effective in maintaining low red blood cell levels at altitudes higher than 4,500 meters.

Scientists discovered that ethnic Tibetans living on the Qinghai-Tibetan Plateau can adapt to high altitude living due to genetic variations that allow them to maintain low red blood cell levels in environments with thin air, state-run Xinhua news agency reported.
In general, the human body reacts to low oxygen levels in the air by producing more red blood cells which transport oxygen between the lungs and body tissue.
But maintaining high red blood cell levels over a long time can result in conditions such as heart failure.
Researchers collected blood samples from ethnic Tibetans in 20 locations at altitudes ranging from 1,900 meters to 5,018 meters.

The study was published in the American Journal of Hematology.