Is Weight Gain Linked To Air Pollution?
It’s Difficult To Lose Weight
Even if you exercise regularly and eat well, the results will vary (and probably disappoint) from those of someone who follows the same routine.
What is the source of this discrepancy? There are many reasons, but one of the most insidious is air pollution, which could be entering your body without your knowledge.
Particles Wreak Havoc On Appetite-Controlling Hormones
The concept of microscopic airborne particles causing weight gain can seem far-fetched, but the science is sound. Fine particles (less than 2.5 microns in diameter) and ultrafine particles (less than 0.1 microns in diameter) are thought to be the contaminants that impair metabolic function the most.
Particle contaminants irritate the alveoli in your lungs, which usually allow oxygen to move through your bloodstream, when you breathe in. As a result, your lungs’ lining releases hormones that reduce the effectiveness of insulin, diverting blood away from insulin-sensitive muscle tissue and preventing the body from adequately controlling blood sugar levels.
Furthermore, particle pollution may cause your body to release more inflammatory molecules called “cytokines” into your bloodstream, causing immune cells to invade otherwise healthy tissue. According to a 2014 study published in the journal Environmental Health, this reaction not only impairs your tissue’s ability to respond to insulin, but the resultant inflammation can also affect the hormones and brain processing that control your appetite.
This can make you feel hungry even when you’re fully satisfied, and the extra food you consume to satisfy your artificial appetite can contribute to weight gain over time – the Berkeley researchers discovered that exposure to air pollution may lead to a 13.6 percent increase in body mass index (BMI), the most widely used metric for determining a healthy weight.
This pollution-induced inflammation could lead to a variety of health problems, including:
However, how did scientists discover a connection between air pollution and obesity? The earliest confirmation, as with many scientific breakthroughs, came from animal experiments that suggested physical responses to airborne contaminants.
Obesity And Air Pollution Have Been Linked In Studies
This topic was first addressed in a 2010 study published in Arteriosclerosis, Thrombosis, and Vascular Biology, which looked at how living in big cities could put people at a higher risk of heart disease than their country counterparts.
Some mice were given clean, filtered air to breathe in the study, while others were exposed to the kind of polluted air found near a congested freeway. The mice were weighed and tested on a regular basis to determine their metabolic function. In just ten weeks, mice exposed to toxic air had more body fat, both around their midsections and around their internal organs, and their fat cells were roughly 20% heavier. The fatter mice also seemed to be less responsive to insulin, which is one of the first signs of type 2 diabetes. Humans are vulnerable to the same troubling health effects, according to many scientific reports.
Obesity And Other Health Issues Can Be Linked To Air Pollution
Over the course of 14 years, a report looked at the medical history of 62,000 individuals in Ontario, Canada. The researchers discovered that every 10 micrograms of fine particles in a cubic meter of air increased the risk of developing diabetes by about 11%, which is a concerning figure given that PM2.5 contamination in some cities and regions affected by wildfires has been measured at 500 micrograms per cubic meter of air.
In a group of nearly 4,000 people living in a highly polluted environment, a 2015 study published in PLOS One found similar evidence of increased hypertension, insulin resistance, and waist circumference.
Children Are Also At Risk
Air pollution, according to scientists, may alter the metabolism of infants and young children, making them more likely to become obese as they grow older. From 1998 to 2006, a longitudinal study published in the American Journal of Epidemiology looked at the health of nearly 800 children growing up in the Bronx borough of New York City.
This research was planned to be as comprehensive as possible in order to ensure that the findings were reliable and revealing – the children’s mothers wore a small backpack that tested air quality as they went about their day while pregnant, and the children’s wellbeing was tracked at regular intervals for the next seven years.
When other factors including diet and income were taken into account, children born in the most highly contaminated areas were 2.3 times more likely to be obese than children born in communities with better air quality. A 2017 study published in Pediatric Obesity found that babies born to mothers who live in highly polluted areas gain weight more quickly than those born to mothers who live in areas with cleaner air, even in the first six months.
It’s important not to place too much emphasis on these results because they can only show a correlation between exposure and result, not that one factor causes another. However, researchers continue to unearth important discoveries that fill in the gaps.
A small group of subjects in Beijing were studied for two years in a study published in Hypertension in 2016. The researchers discovered that when the notorious smog of the big city blanketed the sky, telltale signs of developing issues like insulin resistance and hypertension peaked, adding to the growing body of evidence that air quality is directly related to metabolic processes that lead to obesity.
Air Pollution Is A Worldwide Problem
What can you do to protect yourself from what appears to be an ever-present threat to your health, particularly as scientific research on the link between air pollution and obesity continues to expand?
The scientific community emphasizes that the individual, short-term risk posed by poor air quality should not be interpreted as the sole cause of obesity without taking other factors into account, such as diet and physical activity.
The long-term risk, however, may be huge, given the large number of people living in cities plagued by air pollution — up to 68 percent of the world’s population by 2050, according to the United Nations. When it comes to improving your air quality and losing weight, concentrate on the changes you can create in your own life.
It is clear that no single individual can solve the global air pollution crisis. Other steps that may help boost air quality on a global scale include:
- To reduce traffic congestion in densely populated urban areas, traffic restrictions are implemented
- redesign streets to make them more pedestrian and cyclist friendly
- Invest more in renewable energy sources including wind and solar power
It’s difficult enough to lose weight without having to think about invisible toxins disrupting your metabolism. While you may not be able to control outdoor pollution, you can control your indoor air quality by monitoring it, especially levels of harmful PM2.5, and making meaningful changes in your life today. A healthy diet and regular exercise are still the most important keys to success in your weight-loss journey, but some fresh air can make you feel better overall.