Climbers Battle the Extremes of Mount Everest for Science

Every year, adventurers and thrill seekers dare to climb the tallest mountain on earth, Mount Everest. In the freezing cold peaks of the Himalayas, a community of people known as Sherpas have survived in the harsh environment for thousands of years. They work as guides, navigating lowlanders to the summit of the mountain. The climb is so dangerous that over 290 people have died attempting to reach the summit of Everest. Situations quickly turn deadly when a climber gets too cold, or develops signs of acute mountain sickness. A team of researchers from the University of Cambridge recently traveled to the Himalayas to study the effects of a disease that spells trouble for many people who attempt the climb.

What is Acute Mountain Sickness?

Climber resting during Everest climb, image via Flickr

Acute Mountain Sickness is caused when a person is exposed to an environment with very high altitudes and very low oxygen. Mountain climbers are especially at risk, and if they don’t prepare themselves for the climb, they can risk death. Numerous precautions are taken to avoid a climber from falling ill. Symptoms include fatigue, weakness, feeling short of breath, nausea, and a rapid pulse. If a climber begins to experience any of the symptoms of acute mountain sickness, they must immediately turn around and descend to seek treatment. If left untreated, the condition can progress to a more serious (and fatal) High Altitude Edema. High Altitude Edema causes swelling in the brain that can be deadly.

Another condition that can be very dangerous is hypoxia (meaning low oxygen). Hypoxia occurs when the body doesn’t get enough oxygen from its environment, and as a result, the cells of the body can no longer function, and begin to die. Human brain cells can survive about 3-6 minutes without oxygen; any longer than that, and parts of the brain become too damaged to work again.

 

Why are lowlanders at risk, but not Sherpas?

This is the question the research team from University of Cambridge hoped to answer by studying the way Sherpas’ bodies and lowlanders’ bodies responded differently to higher altitudes. They believe the answer may lie in our genes.

Mount Everest, image via Flickr

Each of us has inherited our genetic traits from our parents, who have inherited their genes from their parents, and so on since the beginning of humanity. Scientists believe that the Sherpas have passed down genetic traits over thousands of years, and these genetic traits have allowed them to be better suited to the extreme environment they live in. For example, the Sherpas’ bodies have developed more efficient ways to pump blood around the body and deliver oxygen to the cells of the body. People from lowlander populations have not needed to develop these same traits to survive in their environments over thousands of years, so these groups are more at risk of falling ill with Acute Mountain Sickness.

Surviving the Extremes

Base camp at Mt. Everest, image via Flickr

Interestingly, the human body has developed ways for us to overcome acute mountain sickness, or even completely prevent it. One method involves allowing the body to “acclimate,” or get accustomed to the low oxygen environments by camping at different altitudes over several weeks. While this takes a lot of time, it allows the climbers to get used to the lower oxygen environment, and their bodies adapt by creating more red blood cells. Red blood cells deliver oxygen through the bloodstream to different parts of the body. The research team discovered that the lowlander group’s bodies became better at providing energy when they gradually got accustomed to the increased altitudes. These changes may not be as effective as the genetic ones that took place over thousands of years, but they do help them survive the harsh conditions of Mount Everest.