High-altitude populations have a lower risk of chronic disease

In a new study led by Binghamton University, researchers have found that high-altitude adaptations are linked to a lower risk of chronic disease. The study was focused on the Mosuo, a Tibetan Buddhist community in the mountains of Southwest China.

Compared to nearby low-altitude populations, the Mosuo are much less likely to develop hypertension or diabetes-associated anemia.

“Understanding of high-altitude adaptations in human populations has grown tremendously in the last decade,” said Professor Katherine Wander. “This explosion of information led us to ask how such adaptations affect chronic disease risk.”

“Our research suggests that Himalayan adaptations to high altitude have additional effects beyond helping people cope with low oxygen availability; they also seem to lower risk for hypertension and, among diabetics, anemia.”

People who have genetically adapted to living at high altitudes in the Himalayas have dilated blood vessels. The increased dilation boosts blood flow and oxygen delivery. The researchers theorized that dilated blood vessels may also lower the risk of hypertension. 

Himalayan high-altitude populations have lost a mechanism that increases red blood cell production in response to low levels of oxygen in the blood. This adaptation protects against greater blood viscosity, a benefit that the research team proposed may help protect from diabetes-related anemia.

The study provided evidence to suggest that both theories are correct. Mosuo risk for hypertension was found to be significantly reduced compared to the low-altitude Hans population. In addition, diabetics were more likely to have anemia among the Han, yet not among the Mosuo.

“As globalization continues to affect the world’s populations, people’s epidemiological and nutritional environments are changing. In most cases, this leads at some point to an increased burden of non-communicable diseases like hypertension, obesity, diabetes, and so on,” explained team leader Siobhan Mattison from the University of New Mexico. 

“Some of this is happening in the Mosuo case – there is a high incidence of diabetes, for example – but our results show that unique adaptations lead to different health consequences for the Mosuo compared to other populations.”

According to the study authors, it is becoming increasingly important to understand how the risk of developing chronic diseases may be affected by genetic adaptations to the local environment.

“Obesity and other chronic diseases are an increasingly global phenomenon, and so it is important to understand how differences across populations interact with the physiology of chronic diseases –  high-altitude adaptations are just one example of such an interaction.”

The study is published in the American Journal of Physical Anthropology.

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By Chrissy Sexton, Earth.com Staff Writer