A study links the consumption of organic foods in children

A study analyzing the association between a wide variety of prenatal and infant exposures and neuropsychological development in school-aged children found that consumption of organic foods is associated with better scores on fluid intelligence tests (ability to solve new reasoning problems) and working memory (the brain’s ability to retain new information when it is needed in the short term). The study, published in Environmental pollution, was conceived and designed by researchers from the Barcelona Institute for Global Health (ISGlobal) – a center supported by the “la Caixa” Foundation – and the Pere Virgili Health Research Institute (IISPV-CERCA).

The explanation for this association may be that “healthy diets, including organic diets, are richer than fast food diets in nutrients needed by the brain, such as fatty acids, vitamins and antioxidants, which, together, can improve cognitive function during childhood, ”commented the leader. author Jordi Júlvez, researcher at IISPV-CERCA who works closely with ISGlobal.

The study also found that eating fast food, crowded homes, and environmental tobacco smoke during childhood were associated with lower fluid intelligence scores. Additionally, indoor fine particulate matter (PM2.5) exposure was associated with lower working memory scores.

The study, titled “Early life multiple exposures and child cognitive function: A multi-centric birth cohort study in six European countries”, used data on 1,298 children aged 6 to 11 from six specific birth cohorts. a European country (United Kingdom, France, Spain, Greece, Lithuania and Norway). The researchers looked at 87 environmental factors children were exposed to in utero (air pollution, traffic, noise, various chemicals and lifestyle factors) and 122 other factors they were exposed to during childhood.

A pioneering study

The aim of the study was to analyze the influence of these exposures on the development and maturation of the human brain, since during childhood the brain is not yet fully developed for an effective defense against environmental chemicals. and is particularly sensitive to toxicity, even at low levels. that do not necessarily pose a risk to a healthy mature brain.

The originality of the study lies in its use of an exposome approach, that is to say the fact that it takes into account all the exposures rather than focusing on just one. This approach aims to better understand the complexity of multiple environmental exposures and their simultaneous effect on the neurological development of children.

Another strength of the study, which analyzes cohorts from six European countries, is its diversity, although this factor also poses the additional challenge of cultural differences, which can influence exposure levels and cognitive outcomes.

Notable associations

The study found that the main determinants of fluid intelligence and working memory in children are organic food, fast food, overcrowding in the family home, indoor air pollution and smoke. of tobacco. To date, there has been little research on the relationship between diet type and cognitive function, but eating fast foods has been associated with lower academic achievement and some studies have also reported positive associations between biological diets and executive function scores. “In our study,” Júlvez explained, “we found better scores of fluid intelligence and working memory with higher organic food consumption and lower fast food consumption.”

In contrast, exposure to tobacco smoke and indoor PM2.5 during childhood can negatively affect cognitive function by increasing pro-inflammatory responses in the brain. Yet, according to Júlvez, it should be borne in mind that “the number of people living together in a household is often an indicator of the economic status of the family, and that contexts of poverty favor less healthy lifestyles, which means which in turn can affect children’s cognitive abilities. the test results “.

Some surprising discoveries

The study also found unexpected associations, which could be explained by confusion and reverse causation. For example, a positive association has been found between children’s exposure to perfluorooctane sulfonic acid (PFOS) and cognitive function, even though PFOS is considered to be an endocrine disruptor that can alter thyroid function and negatively influence development. cognitive.

The study is part of the large European Human Early-Life Exposome (HELIX) project, as is another recent article that used the same exposome and participants, but looked at symptoms of Attention Deficit Hyperactivity Disorder (ADHD) and behavioral problems in children. “We observed that several prenatal environmental pollutants (indoor air pollution and tobacco smoke) and lifestyle habits during childhood (diet, sleep and family social capital) were associated with behavioral disorders in children”, explained Martine Vrijheid, last author of the study and responsible for the study. of the Childhood and Environment program of ISGlobal.

“One of the strengths of this cognition study and the previous study on behavior problems is that we systematically analyzed a much wider range of biomarkers of exposure in blood and urine to determine the internal levels in the model and that we analyzed prenatal and infant exposure. variables, ”Vrijheid concluded.

Tests used to quantify cognitive function:

  1. Raven’s Colored Progressive Matrices (Fluid Intelligence)
  2. Attention network test (attention)
  3. N-Back (working memory)

Cohorts used in the study:

  1. Born in Bradford (BiB), UK
  2. Study of the pre- and postnatal determinants of child development and health (EDEN), France
  3. Infancia y Medio Ambiente (INMA), Spain
  4. Kaunus Cohort (KANC), Lithuania
  5. Norwegian Mother-Father-Child (MoBa) Cohort Study, Norway
  6. Mother-child cohort in Crete (Rhea), Greece

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Reference

Jordi Julvez, Mónica López-Vicente, Charline Warembourg, Lea Maitre, Claire Philippat, Kristine B. Gützkow, Monica Guxens, Jorunn Evandt, Sandra Andrusaityte, Miguel Burgaleta, Maribel Casas, Leda Chatzi, Montserrat de Castro, David Donaire-González, Gražulevičien ?, Carles Hernandez-Ferrer, Barbara Heude, Rosie Mceachan, Mark Mon-Williams, Mark Nieuwenhuijsen, Oliver Robinson, Amrit K. Sakhi, Nuria Sebastian-Galles, Remy Slama, Jordi Sunyer, Ibon Tamayo-Uria, Cathrine Thomsen, Jose Urquiza , Marina Vafeiadi, John Wright, Xavier Basagaña, Martine Vrijheid. Multiple Exposures in Early Life and Childhood Cognitive Function: A Multicenter Birth Cohort Study in Six European Countries. Environmental pollution, Volume 284, 2021, 117404. doi.org/10.1016/j.envpol.2021.117404

About ISGlobal

The Institute of Global Health of Barcelona (ISGlobal) is the result of an innovative alliance between the Foundation “la Caixa” and academic and governmental institutions. The Institute was created to contribute to the work undertaken by the international community to address the challenges of global health. ISGlobal has consolidated a pole of excellence in research and medical care that has its roots in the work started in the world of health care by the Hospital Clínic and the Mar Health Park and in the academic field by the University of Barcelona and Pompeu Fabra University. ISGlobal’s working model is based on the generation of knowledge through its scientific programs and research groups and on the translation of this knowledge into practice and policy through its Education, Policy and Global Development departments. ISGlobal is accredited as a Severo Ochoa Center of Excellence and is a member of CERCA, the network of research centers of the Catalan government.


Patricia J. Callender