A study reveals that when oxygen is scarce there is a beneficial transformation of metabolism that can help reduce weight and prevent cardiovascular and metabolic diseases.
We need oxygen to live. That can make us believe that the more oxygen the better and we seek pure air to breathe deeply. However, as with almost everything, more is not always better; The difference between healthy and toxic lies in the dosage.
A study published in the journal Cell Metabolism explains why people living above 4,500 meters above sea level enjoy a lower incidence of cardiovascular and metabolic diseases, such as diabetes. Researchers say the cause is the lower proportion of oxygen in the air at that altitude.
“When an organism is exposed to chronically low oxygen levels, we find that different organs reorganize their fuel sources and their energy production pathways in various ways,” says the study’s lead author, Dr. Isha Jain, in a statement.
At sea level, oxygen makes up 21 percent of the air. However, for those living above 4,500 meters, oxygen accounts for only 11 percent of the air. Living in these areas for long periods of time forces the human body to adapt to oxygen shortages (hypoxia).
THE HIGH MOUNTAINS TRANSFORM GLUCOSE METABOLISM
In the study at the University of California, San Francisco (United States), laboratory mice were subjected to a situation of hypoxia with 8-11% oxygen. Another group served as control in an atmosphere with 21% oxygen. The researchers observed the rodent’s behavior over a three-week period along with tracking its temperature, carbon dioxide level and blood sugar levels. Using PET (positron emission tomography) scans, it was possible to observe how the different organs consumed nutrients.
It took the mice a couple of days to adapt to the pressure chamber. Mice in hypoxia moved less and sometimes spent hours completely immobile. However, by the end of the third week, their movement patterns returned to normal. Carbon dioxide levels in the blood decreased when the mice breathed faster to get more oxygen, but returned to normal levels after the three-week period.
During the period in hypoxia metabolic changes occurred that were maintained later. Animals that experienced hypoxia had lower blood sugar levels and a weight that never returned to pre-hypoxia levels. The researchers suggest that these long-term changes resemble what doctors see in people living at higher elevations.
HYPOXIA HELPS REDUCE GLUCOSE AND LOSE WEIGHT
Scans of each organ also showed some permanent changes. Normally, the body needs a lot of oxygen to metabolize fatty acids (building blocks of fats) and amino acids (protein components). Less oxygen is needed to metabolize sugar. Mice under hypoxic conditions showed an increase in glucose metabolism, something the researchers expected. But in addition, brown fat and muscles, which consume a lot of glucose, reduced the amount of sugar they normally use.
Dr. Jain explains why the finding makes sense: In conditions of hypoxia, the body needs to find ways to ration its glucose and causes some organs to save. The drop in glucose levels and body weight seen in hypoxic mice is linked to a lower risk of diseases in humans, including heart disease.
Jain and his team hope to develop some clinical applications. For example, drugs that mimic the metabolic benefits of hypoxia could be developed. But spending a season at high altitude could be an effective therapy. It is something that elite athletes do to improve their performance and it is possible that in the future it will be a reasonable medical prescription. On the other hand, in addition to hypoxia, in the high mountain’s temperatures are usually low, which also influences the functioning of metabolism.
WHY DO ATHLETES TRAIN IN HIGH MOUNTAINS?
Athletes train in high mountains to increase the body’s endurance by accustoming it to an environment with little oxygen. The body reacts by producing more red blood cells and thus increases the athlete’s endurance when returning to heights close to sea level.
In addition, altitude training can improve the ability to carry blood, which increases the flow of oxygen-laden red blood cells and improves physical performance. However, there are also risks associated with altitude training, such as the possibility of suffering from acute mountain sickness or respiratory problems due to lack of oxygen.
