Relation between food reinforcement and dopamine genotypes and its effect on food intake in smokers.
BACKGROUND
Food reinforcement and dopaminergic activity may influence food consumption, but research on whether they interact has not been performed.


OBJECTIVE
We assessed the effects of food reinforcement and the interaction of food reinforcement with the dopamine transporter (SLC6A3) genotype and the dopamine D(2) receptor (DRD(2)) genotype on energy consumption.


METHODS
We studied food-consumption and reinforcing-value-of-food tasks in 88 smokers of European ancestry before they enrolled in smoking-cessation treatment. In the food-consumption task, subjects tasted and consumed 8 snack foods ad libitum. The reinforcing-value-of-food task assessed how hard subjects would work for food.


RESULTS
Significant interactions between dopamine genotypes and food reinforcement were observed. Subjects high in food reinforcement who lacked an SLC6A3*9 allele consumed significantly more calories (>150 kcal; P = 0.015) than did subjects low in food reinforcement or those high in food reinforcement who carried at least one SLC6A3*9 allele. Similarly, subjects high in food reinforcement who carried at least one DRD(2)*A1 allele consumed >130 kcal more (P = 0.021) than did subjects low in food reinforcement or those high in food reinforcement who lacked a DRD(2)*A1 allele. There was also a main effect of food reinforcement on energy intake (P = 0.005), with subjects high in food reinforcement consuming 104 kcal (or 30%) more than did subjects low in food reinforcement.


CONCLUSIONS
Food reinforcement has a significant effect on energy intake, and the effect is moderated by the dopamine loci SLC6A3 and DRD(2).
Epstein
Leonard H
LH
Departments of Pediatrics, School of Medicine and Biomedical Sciences, State University of New York at Buffalo, 14214-3000, USA. lhenet@buffalo.edu
Wright
Suzanne M
SM
Paluch
Rocco A
RA
Leddy
John J
JJ
Hawk
Larry W
LW
Jaroni
Jodie L
JL
Saad
Frances G
FG
Crystal-Mansour
Susan
S
Shields
Peter G
PG
Lerman
Caryn
C
D000328:Adult; D000483:Alleles; D000704:Analysis of Variance; D016642:Bupropion / Q000627:therapeutic use; D003216:Conditioning, Operant; D004032:Diet; D004298:Dopamine / Q000235:genetics / Q000378:metabolism*; D050483:Dopamine Plasma Membrane Transport Proteins; D018765:Dopamine Uptake Inhibitors / Q000627:therapeutic use; D002149:Energy Intake / Q000235:genetics / Q000502:physiology*; D005260:Female; D005502:Food; D005838:Genotype; D006801:Humans; D008297:Male; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins / Q000235:genetics*; D009419:Nerve Tissue Proteins / Q000235:genetics*; D011110:Polymorphism, Genetic; D017448:Receptors, Dopamine D2 / Q000235:genetics*; D012054:Reinforcement, Psychology; D012907:Smoking; D016540:Smoking Cessation
D050483:Dopamine Plasma Membrane Transport Proteins; D018765:Dopamine Uptake Inhibitors; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; D017448:Receptors, Dopamine D2; C493214:SLC6A3 protein, human; D016642:Bupropion; D004298:Dopamine