Gene-Environment Interactions in Attention-Deficit/Hyperactivity Disorder Symptom Dimensions: The Role of Unhealthy Food Habits.

Lin Li,Katarina Bälter,Catharina A Hartman,Alejandro Arias Vásquez,Mark J Taylor,Henrik Larsson,Jan Haavik,Tian Xie,Berit Skretting Solberg

doi:10.3390/genes13010047

Abstract

Background: Dietary habits were investigated as environmental risk factors for Attention-Deficit/Hyperactivity Disorder (ADHD). However, no previous studies explored the effects of dietary factors on modifying the role of genetic factors on ADHD. Methods: Based on a Swedish population-based twin study with 1518 twin pairs aged 20–47 years, we tested whether the importance of genetic and environmental effects on ADHD varied as a function of dietary habits. Self-reported dietary habits and ADHD symptoms were collected. Twin methods were used to test the degree to which high-sugar and unhealthy food intake moderated the genetic and environmental influences on ADHD symptoms. Results: In middle-aged adults, genetic influences on inattention symptoms were statistically significantly higher among individuals with higher levels of high-sugar (45%, 95%CI: 25–54%) and unhealthy food intake (51%, 95%CI: 31–60%), compared with those with lower levels of consumption of high-sugar (36%, 95%CI: 25–47%) and unhealthy foods (30%, 95%CI: 20–41%). Similar patterns were also found for the associations between hyperactivity/impulsivity and high-sugar/unhealthy food intake, even though the moderation effects were not statistically significant. Conclusion The present study suggests that genetic factors play a more prominent role in individual differences of ADHD symptoms in the presence of the high consumption of sugar and unhealthy foods. Future longitudinal studies with multiple assessments of ADHD and dietary habits are needed to replicate our findings.

Highlights

This article is an open access articleAttention-deficit/hyperactivity disorder (ADHD) is a common neurodevelopmental disorder characterized by developmentally excessive inattention–disorganization and hyperactivity–impulsivity symptoms [1]
As suggested in previous twin and genetic studies, AttentionDeficit/Hyperactivity Disorder (ADHD) is best viewed as the extreme of a continuous trait that is genetically linked with ADHD [33], in this study, ADHD symptoms were measured on a continuum rather than collapsed to a dichotomous diagnosis
ADHD symptom scores were significantly higher in the group with a high consumption of high-sugar and unhealthy foods, compared to the groups with a low and average consumption, indicating that the higher consumption of high-sugar and unhealthy foods was associated with more ADHD symptoms

Summary

Introduction

This article is an open access articleAttention-deficit/hyperactivity disorder (ADHD) is a common neurodevelopmental disorder characterized by developmentally excessive inattention–disorganization and hyperactivity–impulsivity symptoms [1]. Mental health [1,4]. Both genetic and environmental factors contribute to the risk of ADHD. Twin research indicates moderate-to-large genetic contributions; the estimated heritability (that is, the proportion of phenotypic variation attributable to genetic variation) for ADHD is 30–80%, depending on the age, the assessment method used, and the informants [5,6,7]. The mismatch between the estimated heritability of ADHD from quantitative genetic research and genome-wide association studies (GWAS), together with the multifactorial and polygenetic nature of ADHD [10,11], suggests that, in addition to individual genes and environmental factors, interactions of several genes with each other and with the environment may influence variations in the phenotype

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