Interaction of DRD2/ANKK1 Taq1A Genotype with in-Store Retail Food Environment Exposures on Diet Quality in a Cohort of Quebec Adults.

Food marketing and prices may interact with dopamine-related biology

The foods promoted in shops and the prices attached to them help shape the environment in which dietary choices are made. This study asked whether a genetic marker related to dopamine signaling was associated with different responses to those retail conditions.

Connecting store data with habitual diet. Researchers linked information from 3,532 adults in Quebec’s CARTaGENE biobank with provincial food-retail data. Participants’ food questionnaires were used to calculate a Canadian Healthy Eating Index, a score reflecting the overall quality of their diet. The genetic analysis focused on Taq1A, a variant in the DRD2/ANKK1 region that has been studied in relation to dopamine and reward processing.

The question was whether the relationship between retail exposures and diet quality differed between people carrying the variant and those who did not. Statistical models accounted for several personal characteristics, including sociodemographic factors, body measurements and total energy intake.

Two retail associations depended on genotype. Among carriers, greater exposure to ice-cream displays was associated with poorer diet quality. Vegetable prices also showed an interaction, but the direction was less intuitive: higher prices were associated with better diet quality among carriers, with the opposite pattern among non-carriers. These results describe differences in the observed associations; they do not establish that increasing vegetable prices improves anyone’s diet.

The study suggests that variation in reward-related biology may contribute to differences in responsiveness to retail cues. It also illustrates why averaging everyone together can obscure patterns that vary between groups. The retail environment is complex, and displays and prices can be related to other features of stores, neighborhoods and shoppers.

Because shoppers were not assigned to stores, displays or prices, the analysis cannot isolate their causal effects. Its practical research contribution is to motivate more direct tests of how marketing and affordability interact with individual responsiveness, using observed shopping behavior or controlled changes in retail conditions.