Does Diesel Exposure Lead to Obesity?
Obesity is a serious issue that can significantly impact one’s quality of life and lead to many health concerns. In America, 35.7% of U.S. adults were listed as being obese between 2009-2010; this figure is up by approximately five points from 2000, when 30.5% of U.S. adults were listed as obese. Poor diet coupled with a sedentary lifestyle can influence whether one becomes obese or not, and genetics may also play a role, but is there something else going on?
Unlike being overweight, obesity is defined as having a Body Mass Index, or BMI, of 30 or higher. BMI is calculated using one’s height and weight range. While there’s no question that eating junk food and a lack of physical exercise is not good news for the body, researchers are now adding additional data to the obesity puzzle citing that diesel exhaust exposure while in utero could also be a factor.
According to the FASEB Journal, “Pregnant mice exposed to high levels of air pollution [diesel in this case] gave birth to offspring with a significantly higher rate of obesity and insulin resistance in adulthood than those that were not exposed to air pollution.” To conduct this study, after entering adulthood, mice offspring were placed on either a high-fat diet, consisting of 45% saturated fat, or a low-fat diet, consisting of 10% saturated fat. Researchers found that regardless of their adult diets, male offspring from moms exposed to diesel were heavier than the male offspring from moms exposed to clean air. Interestingly, according to the study, diesel-exposed female offspring were heavier than clean-air exposed females only if they consumed a high-fat diet as adults. Female offspring also never developed indications of insulin resistance, implying hormones may also be at play.
The results from this research, albeit based on mice and not on humans, suggests that air pollution, particularly diesel exhaust, could be adding to the obesity epidemic hitting America as well as other nations, including developing China and India. It’s important to note, although not demonstrated in this study, that obesity in human adults often begins in childhood, when eating habits develop, not just in adulthood.
Nevertheless, what’s interesting about this study, besides its implications for regulatory policy, is that pollution is rarely — if ever — mentioned when linking obesity to lifestyle. It will be interesting to see what other environmental factors may be correlated to this epidemic, in addition to various other common health concerns that are typically isolated to the individual.
Photo Credit: Pastorius