A recent study led by Dr. Trevor Day, a physiologist at Mount Royal University, sheds new light on how the human body adjusts to high altitudes and highlights the unique adaptations of Sherpas, the Tibetan highlanders renowned for their ability to thrive in extreme mountain environments.
Published in the Proceedings of the National Academy of Sciences, the research emphasizes the critical role of the kidneys in helping the body acclimatize to reduced oxygen levels at high altitudes.
High-altitude environments pose significant challenges to the body, particularly in maintaining blood oxygen levels and acid-base balance.
For most people, ascending to such altitudes requires physiological adjustments involving both respiratory and kidney functions.
These adaptations ensure the blood’s pH stays balanced despite lower oxygen availability. However, the study reveals that Sherpas adapt more quickly and effectively than lowlanders to these conditions.
The research was conducted during an international expedition in the Nepal Himalaya, where the team studied two groups: lowlanders with no prior high-altitude exposure and Sherpas, a group with ancestral ties to the Tibetan plateau.
Both groups were matched by age and sex to ensure accurate comparisons. As the participants gradually ascended to 4,300 meters, the researchers analyzed their respiratory and kidney functions to understand how their bodies responded to the high-altitude environment.
The findings were striking. Sherpas demonstrated faster and more pronounced adjustments in their blood acid-base balance compared to lowlanders.
By the time they reached 4,300 meters, Sherpas had achieved fully compensated blood pH levels, meaning their bodies had efficiently adapted to the high-altitude environment.
In contrast, the lowlanders were still experiencing alkalemia, a condition where the blood pH is too high, indicating incomplete acclimatization.
The kidneys played a central role in this process. At high altitudes, the body produces more bicarbonate to maintain acid-base balance. Sherpas’ kidneys were found to regulate this process more effectively, likely due to genetic and evolutionary factors.
Dr. Day noted that these findings provide valuable insight into the evolutionary adaptations of Tibetan highlanders, whose ancestors faced selective pressures that enhanced their renal function and ability to acclimatize.
This study is particularly significant as more people travel to high-altitude regions for work, recreation, and living. Understanding the mechanisms of acclimatization is essential for addressing health issues related to altitude sickness and for improving strategies to help lowlanders adapt.
The research also underscores the importance of ancestry in determining physiological responses. Sherpas, whose genetic heritage has been shaped by generations of living at high altitudes, exhibit unique adaptations that give them an edge in these environments.
These findings not only deepen our understanding of human physiology but also highlight the impressive capabilities of Sherpa populations.
The study was a collaborative effort involving undergraduate students and faculty at Mount Royal University. Nicole Johnson and Jessica Dickenson served as co-first authors, with contributions from Benjamin Mackenzie, Rodion Isakovich, and Dr. Nick Strzalkowski.
While this research offers valuable insights, it has limitations. The study focused on a relatively small number of participants and specific altitude conditions, meaning the findings may not generalize to other populations or environments.
Additionally, more research is needed to pinpoint the exact genetic factors driving Sherpas’ superior kidney function.
Nonetheless, this study provides a foundation for further exploration into how humans adapt to the challenges of high-altitude living and underscores the remarkable physiological capabilities of Sherpas.
If you care about kidney health, please read studies about how to protect your kidneys from diabetes, and drinking coffee could help reduce risk of kidney injury.
For more information about kidney health, please see recent studies about foods that may prevent recurrence of kidney stones, and eating nuts linked to lower risk of chronic kidney disease and death.
The research findings can be found in PNAS.
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