Season of birth, the dopamine D4 receptor gene and emotional eating in males and females. Evidence of a genetic plasticity factor?
Emotional eating has a female preponderance and an understanding of possible genetic and environmental underpinnings is still in the early stages. The current study focuses on the possible role of the dopamine D4 receptor (DRD4) 'plasticity' gene in emotional eating and the possible moderator effects of sex and season of birth therein. We tested this in two samples (n = 93 and n = 586) of male and female Caucasian adults by genotyping DRD4 and assessing self-reported emotional eating. Participants were defined as high risk carriers if they had at least one long (7-repeat) allele, which confers hypo-function to DRD4. We also ran analyses that grouped 2- and 7-repeat carriers together. In the first sample there only was a moderator effect of sex. In the second sample there also was a 3 way interaction between season of birth, sex and genotype. In line with the idea that the Drd4 gene functions as a plasticity gene that affects the sensitivity to environmental influences, the moderator effect of sex was only found for the participants born in fall. Only in females the hypo-functional variants of DRD4 were associated with significantly higher degrees of emotional eating. Furthermore, the sex × genotype effects were somewhat stronger when the 2-repeat allele was grouped together with the 7-repeat allele. Our data suggest that DRD4 hypo-functional genetic variants are associated with emotional eating, only in females.
Institute for Gender Studies and Behavioural Science Institute, Radboud University Nijmegen, Nijmegen, The Netherlands; Faculty of Earth and Life Sciences, Free University Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands. Electronic address: T.vanstrien@psych.ru.nl.
Tatjana
T
van Strien
Centre for Addiction and Mental Health, 250 College Street, Toronto, Canada.
Robert D
RD
Levitan
Behavioural Science Institute, Radboud University Nijmegen, Nijmegen, The Netherlands.
Rutger C M E
RC
Engels
Department of Cognitive Neuroscience, Donders Institute for Brain, Cognition, and Behaviour, Radboud University Medical Centre, Nijmegen, The Netherlands.
Judith R
JR
Homberg
D000328:Adult; D004435:Eating / Q000235:genetics*; D004644:Emotions; D004777:Environment; D005260:Female; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006579:Heterozygote; D006801:Humans; D008297:Male; D008875:Middle Aged; D036801:Parturition; D050638:Receptors, Dopamine D4 / Q000235:genetics*; D012621:Seasons; D012737:Sex Factors; D055815:Young Adult
D050638:Receptors, Dopamine D4
2- and 7-repeat carriers; DRD4; Deficit of reward; Emotional eating; Season of birth; Sex