Why does breathing also cause obesity?

The fact that the air is breathing daily can make the fat person seem irrational, but many studies have proven that this is possible.

According to the researchers, traffic emissions and cigarette smoke are the main causes related to the risk of obesity. Small dust particles from the polluted environment with high reactivity when penetrating can promote widespread infection and disturb human burning activity.

In the short term, this effect is negligible, but if prolonged contact, dust and smoke can cause many dangerous syndromes, besides respiratory diseases.

Enemies not only of the respiratory system

"People are getting to know that polluted air is collected and moved inside the body that not only affects the lungs but also many other parts," said Hong Chen, a researcher from the Institute of Clinical Science and Health. Health community in Ontario, Canada said.

According to BBC, research on experimental mice gave the earliest evidence of the effect beyond the lungs of polluted air. The lead researcher, Quinghua Sun, from Ohio State University, is particularly interested in why urban residents are at higher risk of cardiovascular disease than those living in rural areas.

Lifestyle, according to him, is one of the core causes not to be missed by popular fast food outlets on almost every street that encourages human sugar and fat eating habits. However, Sun always wonders about another invisible cause, hidden in the breathing air every day.

More and more people in the city, especially children with obesity.(Photo: Obese kids).

To clarify this skepticism, Sun began experimenting on mice with living conditions simulating many cities. A group of rats were raised in a clean air environment, while the rest lived in conditions similar to those of the highway or the city center. Along with that, two groups of rats were monitored for weight and did multiple tests to study metabolic function during the study period.

After only 10 weeks, the research team obtained quite clear results. The group of mice affected by pollution has a much thicker layer of fat, both in the waist and viscera. At the microscopic level, their fat cells are also 20% larger than those fed in healthy conditions.

Not only that, the effects of pollution also cause reactions to insulin hormones , hormones that signal cells to convert sugar into energy, becoming less sensitive. This is the first step to diabetes, according to Sun.

The exact mechanism of this situation is still controversial, but later animal experiments agree that air pollution causes a series of reactions in the body.

Small particles or microparticles, smaller than 2.5 micrometers (PM2.5) in diameter, with the same type of dust particles causing pollution in large cities, are considered the main cause. Contamination agents that enter the body affect small air pockets and moisture that allow oxygen to enter the blood, causing the lungs to increase stress responses and overload the brain. In response, the body releases hormones that reduce the effectiveness of insulin and push blood away from insulin-sensitive muscle tissue, blocking blood sugar control.

Microparticles can also produce a series of inflammatory molecules called "cytokines" in the blood, which cause immune cells to attack healthy tissues. Not only hindering tissue insulin sensitivity, then the inflammatory response also disrupts the activity of hormones and the part of the brain that governs appetite in humans, according to Michael Jerrett, of the University of California, Berkeley. , America.

All of these causes combine to destroy the body's energy balance, leading to a range of metabolic disorders, including diabetes and cardiovascular diseases, typically high blood pressure.

Risk to humans

Large-scale studies in many cities around the world indicate that people can suffer the same consequences. Analyzing medical records of 62,000 people in Ontario, Canada for 14 years, Hong Chen expert found that the risk of developing diabetes increased by about 11% for every 10 micrograms of dust / m ^{3 of} air. An alarming number by air pollution in Asian cities can reach 500 micrograms / m ^{3 of} air.

Shanghai residents often wear masks when going to the street. Scientists estimate that air pollution in Asian cities has reached an alarming threshold of 500 micrograms of dust / m ³ .(Photo: Shanghaiist).

A Swiss study also found signs of increased insulin resistance, high blood pressure and waist circumference on a sample of 4,000 people who had to breathe contaminated dust.

More seriously, air pollution can have consequences right from the baby's womb. Many studies have warned that exposure to maternal pollutants during pregnancy may adversely affect metabolic processes, making it easier for children to become obese when they are in school.

Andrew Rundle, from Columbia University, USA, conducted a survey on children born in the Bronx, New York. During pregnancy, the mother wears an exposed air quality measuring device every day. For the next 7 years, the health of the babies participating in the study was closely monitored through regular examinations.

After eliminating weather and dietary factors, Rundle found that babies born in polluted environments are 2.3 times more likely to be overweight than children living in fresh air.

Prudent views and solutions simultaneously

The scientific community is still quite cautious about these ominous results. The reason is, "studies only provide links but cannot prove a close causal relationship between pollution and obesity," said Abby Fleisch, Harvard Medical University.

Fleisch's research also concurs with the trend to show the harmful effects of air pollution on overweight and obesity and dangerous metabolic disorders such as diabetes. She discovered that in the first six months of life, babies living in polluted environments tend to gain weight faster than children who breathe clean air. However, the experts still emphasize caution because it is not yet certain that other factors besides pollution have been completely eliminated.

To date, the missing pieces for a comprehensive understanding are being carried out by some scientific groups with more specific studies.

Research by Robert Brook from the University of Michigan and colleagues in China is a typical example. Surveying the small group for two years, the team concluded, whenever the city was covered by a cloud of polluted dust, the signs of insulin resistance and high blood pressure peaked. These are concrete evidence that air quality actually creates direct effects on the metabolism of the body.

Serious pollution in China makes the bottled clean air become a fever.(Photo: BBC).

The impact of air pollution in the short term is negligible, and it is clear that people cannot ignore lifestyle agents to completely blame the obesity of today's "fatal pandemic". However, with a daily population of breathing seriously polluted air in industrial cities around the world for a long time, the consequences of pollution can be huge.

" Everyone is suffering from the effects of air pollution on a level. This is happening continuously with unintentional exposure, affecting millions of people, so the overall consequences become unpredictable. " Brook worried.

Experts encourage the use of electric vehicles or redesign the street in the direction of reducing the risk of inhaling dust and smoke from bicyclists . In the short term, Brook also mentioned installing air purifiers in homes, schools and offices to eliminate harmful agents.

Most importantly, actions need to be carried out with consensus in communities in undeveloped countries and advanced countries, including big cities like Paris and London, which seem to be in control. Infected, Brook recommends.

"North America and Europe, pollution is being adjusted in the right direction, but we must not fall asleep on the victory," the expert warned.

"Air pollution, should still be placed in the top 10 issues not to be forgotten in the roadmap to improve global health".