|Sherpa of the Himalaya ktwop.com/|
|The Himalayan mountain .earth.com|
A research expedition to Mount Everest has thrown light on this unexplained riddle by studying the physiological basis of amazing adaptations seen in the native Sherpa people, which make them a class apart in the area of mountaineering; they far better suited to high altitude life unlike others. The scientific advantage we get from this rare and unique research is a good understanding of Sherpas' adaptation to oxygen poor environment will help improve the treatment of patients with conditions related to reduced levels of oxygen in the blood and tissues.
Being high altitude dwellers, Sherpas are known to have the rare ability to live and climb high Himalayan mountains where oxygen level is low. No doubt genetic inheritance and natural selection have played a vital role in the development of special traits that help the natives survive at high altitude. However, scientists are yet to understand the physiological basis underlying their far superior endurance power in a fatal environment. In the case of Lowlanders and other high-altitude populations (e.g. Andeans and Ethiopians), they try to cope with the reduced oxygen levels at high altitude by increasing the amount of oxygen carrying cells (hemoglobin) in the body. But in the case of Sherpa it is quite surprising that they do well with less oxygen in their blood. How come they have this unique trait?
The investigation on the physiology of the Sherpas and their adaptation at high altitude was undertaken by a team from University College London's Center for Altitude, Space, and Extreme Environment Medicine on Xtreme Everest 2, a transnational research program undertaken on Mount Everest. The team researched on two different groups one from the Sherpas, and the other naive population of Lowlanders. They took the
baseline measurements in London (50m altitude) and Kathmandu (1300 m altitude) for the Lowlander and Sherpa participants respectively, and then they took repeated measurements from participants as they ascended to the base camp of Mount Everest (5300 m altitude).
The highlight is participants followed an identical ascent profile to each other, and this was done to ensure that the physiological challenge, environmental oxygen content and temperature (which affects the constriction of blood vessels) were matched for all participants. Thus, any differences detected between participants would be attributable to their individual physiology rather than variation in the magnitude or duration of exposure to low levels of oxygen at high altitude.
|Sherpa people, the great heroes of the Himalayas youtube|
The team observed Sherpa people were able to maintain a greater degree of blood flow and oxygen delivery to the working tissues in a changing environment at high altitude on the ascent of Everest. The emerging factfrom this study is Sherpas (in comparison to Lowlanders), are able to deliver more oxygen around their bodies. These unique findings clearly explain as to how Sherpas survive at altitude without increasing hemoglobin content. Little do we realize that high levels of hemoglobin will make the blood thick and viscous. Obviously this will slow down its flow around the body, causing unwanted risk of side effects such as blood clots to the lung. With favorable increased blood flow and oxygen delivery over high oxygen content, Sherpa folks still have the natural ability to provide their tissues with enough oxygen and, at the same time, minimize the risk of potentially fatal side effects.
The low levels of oxygen at high altitude can simulate the reduced oxygen faced by critically ill patients in hospital. A good understanding of the physiology behind Sherpas' ability to survive in a low oxygen environment will help the doctors improve intensive care of patients through new diagnostic and treatment strategies to promote easy flow of blood. There is a small hitch in terms of physiological mechanism that the hospital environment on the ground level is different from the oxygen-poor high mountain environment. Yet another problem is in the hospital doctors deal with heart patients with different heart conditions and they may be ill for a number of reasons. This research study looks at the normal function of the body in an oxygen poor situation as in the case of Sherpas.
Dr Edward Gilbert-Kawai, a co-author of the research is of the opinion, "The mechanisms identified in this study, such as increased blood flow and oxygen delivery to working tissue, feasibly describe an alternative means to aid oxygen delivery in critically ill patients.'' Better new critical care strategies and medicines, besides the underlying cellular mechanisms behind the response may improve the condition of heart patients who experience low oxygen delivery. Such patients can function normally if we come up with right strategy and drugs.
A new study says, ''Sherpas have evolved to become superhuman mountain climbers, extremely efficient at producing the energy to power their bodies even when oxygen is scarce''
Thomas Davies, Edward Gilbert-Kawai, Stephen Wythe, Paula Meale, Monty Mythen, Denny Levett, Kay Mitchell, Michael Grocott, Geraldine Clough, Daniel Martin. Sustained vasomotor control of skin microcirculation in Sherpas versus altitude-naïve Lowlanders-experimental evidence from Xtreme Everest 2. Experimental Physiology, 2018; DOI: 10.1113/EP087236