Air Pollution And Weight Gain: Decoding the Connection

From smog enveloping the cities to the smoke erupting from the kitchens inside the home, air pollution in any form is hazardous to health. According to recent studies, air pollution is responsible for killing an estimated seven million people globally every year. The conjugated effects of outdoor and indoor air pollution are claiming several lives prematurely every year from diseases, such as chronic obstructive pulmonary disease, acute respiratory infections, lung cancer, stroke, and cardiac diseases. 

According to the data presented by WHO, almost 99% of the population across the world breathes polluted air (air exceeding WHO guideline limits), with the most amount of exposure in low- and middle-income countries. 

With the reports of exacerbating air pollution, another debate is gaining momentum- the debate on the connection between air pollution and weight gain. 

According to research conducted by the University of Colorado Boulder, inhaling polluted air can be dangerous for gut bacteria, enhancing the risk of obesity, gastrointestinal disorders, diabetes, and other chronic diseases. 

Air pollution and weight gain: Are they connected? 

9 out of 10 people might shun the integrity of the statement that inhaling polluted air can make you fat. However, it could be true. 

A study published in the journal, Environment International, was the first to draw out a connection between air pollution and the human gut microbiome (the trillions of microorganisms living inside our gut). It mentioned that inhaling polluted air is somewhat linked to the changes in structure and function of the gut microbiome. 

Apart from other polluting agents, cigarette smoke and traffic fumes are the biggest culprits that hamper the ability of our bodies to burn energy. The smoke emerging from cigarettes and vehicles contains inflammatory agents that cause inflammation in our body and disrupt the energy-burning mechanism. 

Interestingly, one might not notice anything wrong (the short-term effects are minimal) until the issue escalates and gives birth to severe disease. And, we must mention that the ill effects aren't limited to the lungs. The polluted air circulating in the body can affect many other body parts and systems.

The study 

The Journal of the Federation of American Societies for Experimental Biology published a study to determine the link between air pollution and obesity. The scientists exposed some rats to heavily polluted air from Beijing, China, while some were exposed to filtered air. The rats that inhaled polluted air demonstrated a significant weight gain. 

The scientists concluded that inhaling carbon monoxide, ozone, nitrogen dioxide, sulfur dioxide, lead, arsenic, benzene, asbestos, bromine, chlorine, methane, halons, particulate matter, and other chemicals can cast an ill effect on health. 

Another study that linked air pollution and weight gained pointed towards vitamin D deficiency as the cause. According to the research, vitamin D deficiency and obesity are closely linked. Atmospheric pollutants reduce our ability to synthesize vitamin D from sunlight (through which we get 90 percent of our body's vitamin D). Lower levels of vitamin D are associated with obesity. 

A study conducted in 2014 also hinted at the connection between air pollution and obesity. The study published in Environmental Health linked air pollution to internal inflammation. As internal inflammation interferes with the activity of hormones and the part of our brain that deals with appetite, the dysfunction leads to overeating, giving way to obesity. 

The mechanism 

Although the mechanism of how polluted air triggers a series of reactions in the body is still not clearly known, one thing is for sure that air pollution can impact health in complex ways.

Scientists believe that small particles that are less than 2.5 micrometers when inhaled can irritate the small and moist air sacs that let oxygen pass into our bloodstream. In response to the irritants, the lungs trigger a stress response. It results in the release of certain hormones that negatively affect insulin's potency. As a result, the body fails at controlling blood sugar levels or simply, burning sugar. 

Apart from disturbing blood sugar, these particles can also stimulate "cytokines", inflammatory molecules. It also triggers immune cells that target healthy tissues. The disturbance in the functioning of tissues affects the way they react to insulin. Furthermore, inflammation affects the hormones and the part of our brain that governs appetite. All these things collectively disturb the metabolism and lead to disorders, such as obesity and diabetes, and cardiovascular issues, such as hypertension. 

Overall health effects of air pollution

Air pollution has ill effects on health. It can cause respiratory irritation and breathing difficulties during exercise and outdoor activities. However, the severity depends on various factors, such as your current health status, type and concentration of pollution, and the length of exposure to pollution. 

Exposure to air pollution can cause several health issues including,

• Aggravated respiratory issues

• Aggravated cardiovascular illness

• Cell damage in the respiratory system

• Stress on lungs and heart to supply more oxygen to the body 

Long term exposure to air pollution can cause permanent health issues including, 

• Lungs aging at a high pace 

• Decrease in lung function 

• Loss of lung capacity 

• Respiratory disorders, such as asthma, emphysema, bronchitis, and cancer 

• Reduced life span 

Effects of air pollution on childhood weight 

In the year 2020, several studies conducted by international researchers concluded that childhood obesity is also linked to air pollution. According to researchers, children exposed to indoor pollutants, such as nitrogen dioxide and particulate matter tend to be obese. 

In 2017, a study published in Pediatric Obesity found out that infants living in highly-polluted places for the first six months of their lives had more weight than infants living in cleaner air. Children surrounded by high levels of pollutants are around two and a half times more susceptible to obesity. 

Some researchers also hint towards the onset of obesity in the womb. A study carried out on a group of pregnant women confirmed that air pollution can affect babies breathing in the womb. In the study, the atmospheric air quality was measured and monitored for a group of pregnant women. Their children were also monitored for the first 7 years of their lives. The study concluded that babies born in highly polluted areas are two and a half times more susceptible to obesity. 

How concerned should we be? 

Exposure to air pollution might not cause any short-term effects. That may be the reason enough for us to disregard the gravity of the issue. But as we are continuously exposed to a high degree of pollution, we should not take it lightly. However, we must also consider the fact that obesity isn't totally linked with air pollution. It is a collective result of several other aspects of lifestyle. 

Talking solely about the role of air pollution in obesity, the continuous and involuntary exposure to air pollution affects everyone to some degree. Over time, the overall impact becomes greater. 

The solution 

Well, the world knows the solution, but it is difficult to implement. However, we must take responsibility for our contribution to it.

If we start using electric or hybrid vehicles, we could be able to control traffic pollution to a great extent. With these changes, cyclists and pedestrians will not be exposed to high pollution. Furthermore, the use of air purifiers at homes, offices, schools, shopping malls, etc., will help in filtering out harmful elements. 

The world should stand united and swear by adopting these small changes. The developed and the developing countries should bring the pollution under the scanner and take measures to control it. We must understand that controlling air pollution is the key to a healthy world. 

The bottom line 

Limiting exposure to air pollution is crucial to leading a healthier lifestyle. We must keep ourselves safe from the ill effects of pollution by being mindful of our choices and energy consumption.

As mentioned, monitoring outdoor and indoor air quality using high-efficiency air purifiers, not exposing yourself to poor air quality, and wearing high-quality masks are some things you can do to avoid inhaling polluted air as well as preventing the chances of becoming obese.