Scientists have long wonderedwhy the people of Tibet can live in high latitudes without showing the symptoms that other people experience at this altitude. New research reveals that Tibetans have evolved by developing10 special genes that allow them to process oxygen differently than ordinary mortals. The finding, states the study published in the journalScience, could lead to the development ofnew treatments for so-called “mountain sickness”.
Tibet is the highest region on Earth, with an average height of 4,900 meters. According to the study, the people of Tibet began to adapt genetically about a thousand years ago toavoid polycythemia, a disorder in which the body produces an excessive level of red blood cells when it is deprived of oxygen, which is what can occur when mountaineers, for example, scale the highest peaks in the world. This is because at high latitudesthe atmosphere contains much less oxygen than at sea level.
Among the complications that polycythemia can cause are inflammation of the lungs and brain and pulmonary hypertension that can lead to respiratory failure. But none of that seems to affect Tibetans. As explained by researchers at the University of Utah School of Medicine in the United States and the Qinghai University School of Medicine in China, even at altitudes of 4,000 meters or more above sea level, most of the Inhabitants of Tibet do not overproduce red blood cells and do not develop the complications of polycythemia.
Other populations, such as those in the Andes in South America and the people of the Ethiopian highlands in Africa, are known to have developed evolutionary adaptations to live in these places. But according to scientists, Tibetans have evolved with genes that no other high-latitude population possesses. The first analyzes show that these 10 genes have allowed Tibetans to develop more efficient metabolic processes so as not to produce excess red blood cells where there is less oxygen. What’s more,Tibetans have a higher level of nitric oxide in the body, a compound that may help carry more oxygen to the tissues.
