A new study has challenged the assumption that childhood obesity directly affects language development, suggesting instead that the two share a genetic link. Researchers in Singapore used data from the Growing Up in Singapore Towards Healthy Outcomes (GUSTO) cohort to explore whether obesity causally influences language skills or if both traits are linked through genetic factors. The findings were published in the journal eBioMedicine.
Jian Huang, PhD, the lead author and a senior scientist at A*STAR Institute for Human Development and Potential, said: “Previous research has highlighted links between cardiometabolic health and neurocognitive outcomes. For example, while dementia can impact communication and language, early language development is crucial for cognitive growth. Although childhood obesity may be associated with suboptimal neurodevelopment, these findings are often confounded by socioenvironmental factors.”
The study examined the polygenic risk scores of children to determine the relationship between obesity and language ability. The findings revealed that children with a higher genetic risk for obesity tended to perform worse on language assessments at age nine. However, rather than establishing a direct causal pathway from obesity to reduced language proficiency, the study suggested a shared genetic basis between the two.
“Our study shows that genetic variants linked to obesity are also associated with early language development in children,” noted Dr Huang. “This relationship is likely due to a shared genetic basis between obesity and language-related skills rather than a direct causal effect of higher obesity on language abilities.”
The research team investigated the role of neurology-related proteins and white matter microstructure in language development. The expressions of specific proteins, EFNA4 and VWC2, were linked to both obesity and language ability. These proteins play a role in brain myelination, a process essential for efficient communication between neurons. The study also identified the involvement of the EPH-Ephrin signalling pathway in the hippocampus, a brain region crucial for memory and learning.
“Additionally, our data suggest that EPH-Ephrin signalling may play a role in language development,” added Huang. “Overall, these insights underscore the potential of integrating early-life proteomic analyses with deep genotyping and phenotyping to enhance our understanding of child health and development at a molecular level.”
Although the results pointed to a connection between genetic predisposition to obesity and lower language scores, they did not confirm that obesity itself causes poorer language skills. The study used Mendelian randomisation, a method that helps determine causality in genetic research, but did not find strong evidence that obesity leads to language difficulties. Instead, the observed associations were likely due to common genetic factors influencing both traits.
Previous research has highlighted the potential impact of childhood obesity on cognitive development, but findings have been inconsistent due to the difficulty of separating genetic influences from environmental factors. This latest study offers a new perspective by focusing on genetic predisposition rather than weight alone. By using a trans-ancestry polygenic risk score, researchers were able to integrate genetic data from different populations, increasing the reliability of their findings.
The study also explored the potential influence of early-life obesity management on cognitive outcomes. While obesity has been linked to neurological changes, the findings suggest that addressing weight-related health risks may not necessarily improve language development. Instead, understanding the genetic factors that contribute to both obesity and language skills could help shape future interventions.
“These findings emphasise the need for more comprehensive early-life proteomic profiling to further elucidate the molecular links between cardiometabolic health and neurodevelopment,” said Dr Huang. “We are actively developing an extensive early-life proteomics resource that will help reveal how early human development lays the foundation for future health trajectories.”
The results highlight the complexity of childhood development, showing that multiple biological pathways influence cognitive and physical health. The researchers suggest that further studies should explore how genetic and environmental factors interact to shape language skills. They also emphasise the importance of considering genetic influences when developing strategies to support children’s cognitive growth.
