Nav: Home

Lessons from Everest's Sherpas could aid intensive care treatment

September 04, 2018

A research expedition to Mount Everest has shed light on the unique physiological basis of adaptations seen in the native Sherpa people, which make them better suited to life at high altitude. This improved understanding, which forms part of new research published in Experimental Physiology, could help improve the treatment of patients with conditions related to reduced levels of oxygen in the blood and tissues.

Sherpas are native, ancestral high-altitude dwellers, who are renowned for their ability to live and climb at Himalayan altitudes, where oxygen content is lower. Whilst genetic inheritance and natural selection are likely to have developed traits in Sherpas that favour survival at high altitude, the physiological basis underlying their superior performance has proven elusive. Strikingly, whilst Lowlanders and other high-altitude populations (e.g. Andeans and Ethiopians), cope with the reduced oxygen levels at high altitude by increasing the amount of oxygen carrying cells (haemoglobin) in the body, Sherpas do not. This has always seemed somewhat perplexing and counter-intuitive, for how do they do so well with less oxygen in their blood?

This question was investigated by researchers from University College London's Centre for Altitude, Space, and Extreme Environment Medicine on Xtreme Everest 2, a translational research programme undertaken on Mount Everest. The team conducted research that compared participants drawn from two distinct populations: Sherpas, and an altitude naive population of Lowlanders. Baseline measurements were obtained in London (50m altitude) and Kathmandu (1300m altitude) for the Lowlander and Sherpa participants respectively, and then repeated study measurements were taken from participants as they ascended to the base camp of Mount Everest (5300m altitude). Individuals followed an identical ascent profile to each other, which ensured 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.

It was found that as the amount of surrounding environmental oxygen decreases on ascent of Mount Everest, Sherpas are able to maintain a greater degree of blood flow and oxygen delivery to the working tissues. In essence, this shows that Sherpas (when compared to Lowlanders), are able to deliver more oxygen around their bodies. These novel findings might also explain how Sherpas thrive at altitude without increasing haemoglobin content. High levels of haemoglobin make the blood thick and viscous, thus not only slowing down its flow around the body, but also increasing the risk of side effects such as blood clots to the lung. Conceivably, by favouring increased blood flow and oxygen delivery over high oxygen content, Sherpas are still able to provide their tissues with ample oxygen, yet minimise 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. Therefore, by understanding the physiology behind Sherpas' success in low oxygen environments we could help improve intensive care of patients through the design of novel diagnostic and treatment strategies. Of course, it is possible that physiological mechanisms at altitude may differ from those seen in hospital patients. However, studies on unwell hospital patients are fraught with ethical difficulties, and, as patients may be ill for a number of different reasons (e.g. heart attack or chest infection), teasing apart what physiological responses are due to the lack of oxygen per se, rather than the symptoms of the underlying illness or any treatments that are being applied, is extremely difficult.

Dr Edward Gilbert-Kawai, a co-author of the research was delighted with this paper's findings: "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. Future research should establish the underlying cellular mechanisms behind this response. Identifying such differences and mimicking those in humans most highly adapted to reduced environmental oxygen may thus reveal novel target pathways that are amenable to drug treatment in the critically ill, and could provide new directions in critical care medicine."

Dr Dan Martin, a member of the Xtreme Everest 2 research programme, is giving a free public lecture at Europhysiology (London) on Friday 14th September. Register at

The Physiological Society

Related Blood Flow Articles:

Blood flow monitor could save lives
A tiny fibre-optic sensor has the potential to save lives in open heart surgery, and even during surgery on pre-term babies.
Changes in blood flow tell heart cells to regenerate
Altered blood flow resulting from heart injury switches on a communication cascade that reprograms heart cells and leads to heart regeneration in zebrafish.
Blood flow command center discovered in the brain
An international team of researchers has discovered a group of cells in the brain that may function as a 'master-controller' for the cardiovascular system, orchestrating the control of blood flow to different parts of the body.
Researchers closer to new Alzheimer's therapy with brain blood flow discovery
By discovering the culprit behind decreased blood flow in the brain of people with Alzheimer's, biomedical engineers at Cornell University have made possible promising new therapies for the disease.
In vitro grafts increase blood flow in infarcted rat hearts
Advances in stem cell research offer hope for treatments that could help patients regrow heart muscle tissue after heart attacks, a key to patients achieving more complete recoveries.
Balloon-guided catheters provide better blood flow following stroke interventions
Patients who have experienced a stroke as a result of blockages of the arteries in the brain have better outcomes with the use of balloon-guided catheter surgery as compared to having a conventional guided catheter procedure.
Scientists developed new contactless method of measuring blood flow in hands
Russian researchers proposed a new contactless method for measuring blood flow in the upper limbs.
Researchers investigate correlation between blood flow and body position
For the first time ever, an international research group detected alterations in capillary blood flow around the face caused by body position change.
Restoring blood flow may be best option to save your life and limb
Amputation for severe blockages in the lower limbs has a lower survival rate than other treatment options that restore blood flow.
Blood flow in the heart revealed in a flash
Researchers at Linköping University have for the first time been able to use information from computer tomography images to simulate the heart function of an individual patient.
More Blood Flow News and Blood Flow Current Events

Top Science Podcasts

We have hand picked the top science podcasts of 2019.
Now Playing: TED Radio Hour

Accessing Better Health
Essential health care is a right, not a privilege ... or is it? This hour, TED speakers explore how we can give everyone access to a healthier way of life, despite who you are or where you live. Guests include physician Raj Panjabi, former NYC health commissioner Mary Bassett, researcher Michael Hendryx, and neuroscientist Rachel Wurzman.
Now Playing: Science for the People

#543 Give a Nerd a Gift
Yup, you guessed it... it's Science for the People's annual holiday episode that helps you figure out what sciency books and gifts to get that special nerd on your list. Or maybe you're looking to build up your reading list for the holiday break and a geeky Christmas sweater to wear to an upcoming party. Returning are pop-science power-readers John Dupuis and Joanne Manaster to dish on the best science books they read this past year. And Rachelle Saunders and Bethany Brookshire squee in delight over some truly delightful science-themed non-book objects for those whose bookshelves are already full. Since...
Now Playing: Radiolab

An Announcement from Radiolab