A day with high air pollution can increase an individual's blood pressure and risk of stroke, according to the Centers for Disease Control and Prevention. But it also poses another threat -- weight gain.
Diet and genetics are, of course, factors known to contribute to obesity. But Dr. Amie Lund, associate professor of UNT Biological Sciences, is currently investigating if increased inflammation in the cells or tissues caused by exposure to air pollution also contributes to weight gain. She is in the middle of research from a three-year, $437,964 Academic Research Enhancement Award from the National Institutes of Health and its National Institute of Environmental Health Sciences.
Using an inbred strain of mice, she studied two groups -- one group on a high-fat diet and the other on a low-fat diet -- that were exposed by inhalation to a mixture of gas and diesel emissions. When she looked at the weight and fat cells of the animals, Dr. Lund noticed the difference.
"Exposure to air pollution appears to promote fat cells and store more fat, increase inflammation and alter signaling pathways within the cells," says Dr. Lund, who works in research labs both in UNT's Environmental Education Science and Technology Building and the Science Research Building.
Dr. Lund also saw changes in these pathways in the low-fat animals -- considered the equivalent of a young, healthy adult -- albeit to a lesser degree than those animals consuming a high-fat diet. One of these is the renin-angiotensin system signaling pathway, which helps regulate blood pressure and could lead to hypertension when the pathway is overactive.
How can this be prevented? Environmental regulation and filtration systems can help minimize exposure to the pollutants. Also, drugs currently available can target the reduction of renin-angiotensin signaling in the body, but it is unclear if they also can provide beneficial outcomes in altering the signaling of fat cells in obese patients.
"It's important to understand how environmental factors are driving the response in the fat cells," Dr. Lund says. "Until we understand which factors may contribute to obesity, we can't address them."
She says the overall goal is to establish toxicity guidelines for environmental pollutants. That can assist with setting regulatory limits for environmental exposure in order to reduce adverse human health.
The possibilities for investigating the effects -- and solutions -- of air pollution are endless. But that doesn't deter the researchers.
"It's exciting," Dr. Lund says. "We're just scratching the surface. There will always be the next question to answer."