Childhood obesity linked to multiple environmental factors in unique study
Childhood obesity is an increasingly common health threat around the world. It later increases the risk of various life-threatening problems including type 2 diabetes, cancer, heart disease, and even mental health issues.
A new study by scientists at USC and the Barcelona Institute for Global Health (ISGlobal) is the first to provide a comprehensive profile of environmental factors linked to childhood obesity. Research has shown 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 growth – as well. than air pollution and certain characteristics observed in certain urban areas. . Differences in socioeconomic status did not explain these results.
The results have just been published in the journal Environmental health perspectives.
“People aren’t exposed to a single chemical in their lifetime,” said Leda Chatzi, MD, PhD, associate professor of preventive medicine at USC’s Keck School of Medicine and lead author of the study. . “They are exposed to multiple chemicals. With this in mind, we try to understand the totality of environmental exposures. “
Dr Chatzi and his colleagues are exploring the exposome, a company designed to complement genome research. Just as many genome studies attempt to clarify how gene content affects health, studies like this attempt to clarify how health is affected by each environmental influence since conception. This new approach contrasts with a traditional method of surveying the health of the population, focusing on one or two environmental factors in a given survey.
In total, the article looked at 173 factors – 77 during pregnancy and 96 during childhood. These included air pollutants, the human-made environment of families and access to green spaces, tobacco smoke and chemical pollutants such as heavy metals and pesticides.
The researchers studied a group of about 1,300 children aged 6 to 11 from six European countries: France, Greece, Lithuania, Norway, Spain and the United Kingdom. Data on women and their children were collected during pregnancy as part of a collaborative longitudinal research project known as the Human Early Life Exposome (HELIX) study.
Exposure to tobacco, air pollution and lack of exercise
Smoking by mothers during pregnancy was the most important association with high BMI in children, and the only prenatal factor with a significant association. Additionally, a high BMI was associated with exposure to secondhand smoke, as measured by the levels of a certain chemical in children’s urine samples. Taken together, these findings suggest that breaking the habit – or never resuming it – is a way for parents to protect the long-term health of their offspring.
“It’s a pretty important message,” said Dr Chatzi. “Maternal smoking during pregnancy and second-hand smoke exposures are quite prevalent around the world. “
Exposure to air pollution, both indoors and outdoors, was another factor linked to a higher BMI. The specific pollutants were nitrogen dioxide – a component of automobile exhaust and other gases released during the combustion of fossil fuels – as well as particles in the atmosphere.
Certain attributes of the areas where children live also showed a strong correlation with BMI. BMI was higher for children who live in densely populated areas. But BMI was lower for those who attended school in areas denser in facilities such as businesses, community services, educational institutions, restaurants, and stores – an indicator of walking d ‘a neighborhood.
“With more facilities, children can walk, cycle, play sports,” said Dr Chatzi. “You can compare that with what is described as food deserts or areas with less facilities. “
The researchers note that a better understanding of the impact of environmental exposure could create opportunities to take actions that reverse the trend of increasing childhood obesity, ultimately mitigating its long-term dangers.
“These results provide further evidence that changing environmental exposures early in life can limit the risk of obesity and associated complications,” said lead author Martine Vrijheid, professor-researcher at ISGlobal and principal investigator of the HELIX project. . “The implications for public health are important as these findings may help identify obesity-related exposures that could be targeted for prevention and intervention early in life.”
About this study
Besides Dr Chatzi and Vrijheid, the co-authors of the studies are Serena Fossati, Léa Maitre, Sandra Marquez, Maribel Casas, Montserrat de Castro, David Donaire-Gonzalez, Oliver Robinson, Jordi Sunyer, Ibon Tamayo-Uria, Jose Urquiza, Antonia Valentin, Charline Warembourg, Mark J. Nieuwenhuijsen and Xavier Basagaña from the ISGlobal Institute, Barcelona, Spain; Theano Roumeliotaki and Marina Vafeiadi from the Department of Social Medicine, Faculty of Medicine, University of Crete, Heraklion, Crete, Greece; Lydiane Agier, Solène Cadiou and Valérie Siroux from the Team of Environmental Epidemiology Applied to Reproduction and Respiratory Health, INSERM, CNRS, Université Grenoble Alpes, Institut des Biosciences Avancées (IAB), Joint Research Center U1209, Grenoble, France ; Sandra Andrusaityte, Audrius Dedele and Regina Grazulevicene from the Department of Environmental Sciences, Vytautas Magnus University, Kaunas, Lithuania; Line S. Haug, Helle Margrete Meltzer, Eleni Papadopouplou, Amrit K. Sakhi, Per E. Schwarze and Cathrine Thomsen of the Norwegian Institute of Public Health, Oslo, Norway; and Rosemary McEachan and John Wright of the Bradford Institute for Health Research, Bradford Teaching Hospitals NHS Foundation Trust, Bradford, UK.
This study was supported by the Seventh Framework Program of the European Community (Human Early Life Exposome Project, Grant ID: 308333) and by the National Institute of Environmental Health Sciences (R21ES029681).
– by Wayne Lewis