From the maternal uterus to adolescence: they create an atlas of the determinants of child health

BarcelonaTobacco smoke during pregnancy, air pollution, exposure to certain chemicals, or dietary habits during childhood can have health repercussions that persist at least until adolescence. This is pointed out by a European study published this Friday in Science Advances, which analyzes nearly 200 environmental exposures from before birth –in the maternal womb– and during the first years of life. The research indicates that there are several factors that can influence the cardiovascular, metabolic, and mental functioning of young people.

The study, led by the Barcelona Institute for Global Health (ISGlobal) –a center promoted by the La Caixa Foundation–, was conducted in collaboration with the French National Institute of Health and Medical Research (Inserm) and is part of the Human Early Life Exposome (HELIX) project. The scientific community has been studying for years how environmental factors, beyond genetics and individual characteristics, influence human health. The novelty of this assessment is that it does not limit itself to evaluating them one by one, but rather allows for the creation of an atlas of epidemiological associations –but not cause-effect– between environmental exposures during gestation, childhood (from 6 to 11 years old), and adolescence (from 12 to 18 years old) and health.

ISGlobal and University of Barcelona researcher Augusto Anguita-Ruiz is the lead author of the study and explains that the research was based on the exposome, the set of environmental, household, and lifestyle exposures that can leave a mark on our health. The objective is to study the associations of these nearly 200 factors with four areas: cardiometabolic health, which includes body mass index (BMI) and blood pressure; mental health, especially regarding attention deficit hyperactivity disorder (ADHD), anxiety, depression, aggressiveness, or impulsivity; respiratory health, such as asthma; and allergies and dermatitis.

Among the most relevant results of this research, based on 586 pairs of European mothers and children, is that maternal smoking during pregnancy is associated with a higher BMI and more aggressive or impulsive behaviors in children, both during childhood and adolescence, as well as with more ADHD symptoms during adolescence. It also links high maternal meat intake during pregnancy with various mental health problems and childhood asthma, as well as with wheezing –respiratory sounds– and dermatitis during childhood.

Another example: higher exposure to fine PM 2.5 particles during childhood is associated with worse mental health, metabolic, and cardiovascular system indicators. But not all exposures have unfavorable associations: the Mediterranean diet and higher fruit consumption during childhood favor better body mass index and blood pressure levels, according to the study.

More studies will be needed

The team used data from 69 prenatal exposures and 129 during childhood, along with eleven health indicators. Among the factors analyzed were diet, physical activity, sleep, and other individual behaviors, as well as exposure to chemical pollutants, metals, and the built environment, such as residential density. While the authors admit that no exposure was associated with all four health domains at once, approximately one in three was linked to more than one domain. “This suggests that certain exposures can have broad effects and affect various systems of the organism,” argues Valérie Siroux, an Inserm researcher and senior co-author of the study.

In the researchers' view, this resource may contribute to formulating new hypotheses, guiding future research, and promoting new public policies. However, among the study's limitations is the sample size, which did not allow for the study of potential gender differences, and the need to continue investigating the mechanisms that explain these relationships. “Further studies with larger and more diverse populations will be needed to better understand these relationships and determine whether modifying some of these exposures can change the evolution of health during childhood and adolescence,” concludes Xavier Basagaña, an ISGlobal researcher and senior co-author.