Gene by cognition interaction on stress-induced attention bias for food: Effects of 5-HTTLPR and ruminative thinking.

INTRODUCTION: Stress is often found to increase the preference and intake of high caloric foods. This effect is known as emotional eating and is influenced by cognitive as well as biological stress vulnerabilities. An S-allele of the 5-HTTLPR gene has been linked to decreased (brain) serotonin efficiency, leading to decreased stress resilience and increased risks for negative affect and eating related disturbances. Recently it has been proposed that a cognitive ruminative thinking style can further exacerbate the effect of this gene by prolonging the already increased stress response, thereby potentially increasing the risk of compensating by overeating high palatable foods.

OBJECTIVE: This study was aimed at investigating whether there is an increased risk for emotional eating in high ruminative S/S-allele carriers reflected by an increased attention bias for high caloric foods during stress.

METHODS: From a large (N=827) DNA database, participants (N=100) were selected based on genotype (S/S or L/L) and ruminative thinking style and performed an eye-tracking visual food-picture probe task before and after acute stress exposure. A significant Genotype x Rumination x Stress-interaction was found on attention bias for savory food; indicating that a stress-induced attention bias for specifically high-caloric foods is moderated by a gene x cognitive risk factor.

CONCLUSION: Both a genetic (5-HTTLPR) and cognitive (ruminative thinking) stress vulnerability may mutually increase the risk for stress-related abnormal eating patterns.