Childhood Obesity Tied to More Than One Environmental Factors
A new study led by researchers at the Barcelona Institute for Global Health (ISGlobal) and the University of Southern California (USC) is the first to comprehensively identify environmental factors linked to childhood obesity.
Childhood obesity is becoming more and more common worldwide. It increases risk later on for a variety of life-threatening conditions, including type 2 diabetes, cancer, heart disease and even mental health problems.
The findings show that a higher body mass index (BMI), an estimate of body fat, during childhood is associated with exposure to smoking — both in the womb and during childhood — as well as air pollution and certain characteristics seen in some urban areas. Differences in socioeconomic status did not explain these results.
The study is published in the journal Environmental Health Perspectives.
“People are not exposed to only one chemical during their lives,” said Dr. Lida Chatzi, professor of preventive medicine at the Keck School of Medicine of USC and the senior author of the study. “They are exposed to multiple chemicals. With that in mind, we try to understand the totality of environmental exposures.”
Overall, the paper looked at 173 factors — 77 during pregnancy and 96 during childhood. These included air pollutants, families’ human-made surroundings and access to green space, tobacco smoke and chemical pollutants such as heavy metals and pesticides.
The research team studied a group of about 1,300 children, ages 6 to 11 years, from six European countries: France, Greece, Lithuania, Norway, Spain and the United Kingdom. Data about the women and their children have been gathered, starting at pregnancy, through a collaborative longitudinal research project known as the Human Early Life Exposome (HELIX) study.
Mothers’ smoking during pregnancy was the strongest link to high BMI among children, and the only prenatal factor with a significant association. In addition, high BMI was associated with exposure to secondhand smoke, as measured through levels of a certain chemical in children’s urine samples. Taken together, these findings suggest that kicking the habit or never picking it up is one way that parents can safeguard the long-term health of their offspring.
“This is quite an important message,” Chatzi said. “Maternal smoking during pregnancy and exposures to secondhand smoke are quite prevalent worldwide.”
Exposure to air pollution, both indoors and out, was another factor linked to higher BMI. Specific pollutants were nitrogen dioxide, a component of automobile exhaust and other gases released when fossil fuels burn, as well as particles in the atmosphere.
Certain characteristics of the areas where children live also showed a strong link to BMI. BMI was higher for children who live in densely populated areas. But BMI was lower for those who went to school in areas that are denser in facilities such as businesses, community services, educational institutions, restaurants and shopping, a proxy for a neighborhood’s walkability.
“With more facilities, children can walk, ride their bikes, go play sports,” Chatzi said. “You can contrast this with what are described as food deserts, or areas with fewer facilities.”
The researchers note that better understanding of the impact of environmental exposure could create opportunities to take action that reverses the trend of increasing childhood obesity, ultimately mitigating its long-term dangers.
“These findings provide further evidence that modifying environmental exposures early in life can limit the risk of obesity and associated complications,” said first author Dr. Martine Vrijheid, research professor at ISGlobal and principal investigator of the HELIX project.
“The implications for public health are important since these results may help to identify obesity-related exposures that could be targeted for prevention and intervention early in life.”
Source: Keck School of Medicine of USC
Pedersen, T. (2020). Childhood Obesity Tied to More Than One Environmental Factors. Psych Central. Retrieved on September 29, 2020, from https://psychcentral.com/news/2020/06/25/childhood-obesity-tied-to-more-than-one-environmental-factors/157611.html