The secret to a healthier life may be moving to the mountains. A new study has revealed that two million people who live at an altitude of more than 4,500 meters have lower rates of metabolic conditions such as diabetes and coronary heart disease.
The new study suggests that it’s not just daily hikes in the mountains that get us in shape. According to researchers, the reason behind good health stems from low oxygen levels. Understanding how these levels affect health could lead to new strategies for treating metabolic diseases.
“When an organism is exposed to chronically low levels of oxygen, we find that different organs redistribute their fuel sources and their energy production pathways in various ways,” said Isha Jain, one of the study’s authors.
“We hope these findings will help us identify metabolic switches that may be beneficial for metabolism even outside of low-oxygen environments.” Study Finds.
At sea level, oxygen constitutes 21% of the air. However, for those who live above 4,500 meters oxygen represents only 11% of the air. Living in these areas for long periods of time forces the human body to adapt to the oxygen shortage – also known as hypoxia.
In this recent study, published in Cell Metabolism, Jain and colleagues looked at the long-term impact of hypoxia on organs throughout the body. “We wanted to profile the metabolic changes that occur as the body adapts to hypoxia,” said Ayush Midha, another of the authors.
The team placed adult mice in pressure chambers that contained 21%, 11% or 8% oxygen – levels where both mice and humans can survive. The researchers observed behavior over a three-week period, along with tracking temperature, carbon dioxide and blood sugar levels, as well as nutrient intake.
It took a few days for the rats to adjust to the pressure chamber. Rats in hypoxic conditions (11% and 8% oxygen levels) moved less and spent hours completely still. However, by the end of the third week, their movement patterns had returned to normal. Blood carbon dioxide levels decreased when breathed faster to get more oxygen, but this returned to normal levels after the three week period.
However, the rats’ metabolism was permanently altered. Hypoxic animals had lower blood sugar levels and weight, which never returned to prehypoxic levels. The researchers suggest that these long-term changes are similar to what doctors find in people who live in higher elevations.
Normally, the body needs tons of oxygen to metabolize fatty acids and amino acids. Less oxygen is needed to metabolize sugar. Rats under hypoxic conditions showed an increase in glucose metabolism, an observation that the researchers expected.
The unexpected discovery was that adipose tissue and skeletal muscle reduced the amount of sugar they normally use.
“Prior to this study, the assumption was that under hypoxic conditions, the entire body’s metabolism becomes more efficient at using oxygen, meaning it burns more glucose and less fatty acids and amino acids. We have shown that while some organs are actually consuming more glucose, others become glucose sparsers,” explained Isha Jain.
The drop in glucose levels and body weight seen in hypoxic rats is linked to a lower risk of disease in humans. The discovery is a step toward creating new drugs that mimic the metabolic benefits that hypoxia or high-altitude travel provide to human health.
The team’s next work involves using hypoxic conditions to study individual cell types and levels of signaling molecules.
“We already see athletes who are going to train at altitude to improve their performance; maybe in the future, we’ll start to recommend that people spend time at high altitude for other health reasons,” concludes Ayush Midha.