Editors' ChoiceMetabolism

Alcohol’s BOLD effect on food intake

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Science Translational Medicine  08 Jul 2015:
Vol. 7, Issue 295, pp. 295ec113
DOI: 10.1126/scitranslmed.aac8109

We’ve long known that a pre-meal cocktail stimulates food consumption, with reports of up to a 30% increase in intake. Indeed, apéritifs—spirits served before a meal—traditionally serve the purpose of stimulating the appetite. Yet the mechanisms that underlie increased intake after alcohol consumption remain unclear—although scientists have proposed that the disinhibition of eating restraint, enhancement of the appetite, and stimulation of food-reward systems might be at play. Now, Eiler et al. use functional magnetic resonance imaging (fMRI) to investigate the effects of alcohol intoxication on regions of the brain that mediate reward and feeding behavior.

In this study, 35 nonobese women were evaluated over two separate lunchtime sessions: once during a controlled intravenous infusion of alcohol and again during a saline infusion. The intravenous administration allowed for the evaluation of alcohol effects specific to the brain and independent of the digestive system, adding to the novelty of the study. During each fMRI session, participants were exposed to a meat aroma (roast beef or Italian meat sauce), and the brain’s blood oxygenation level–dependent response (BOLD) was measured in target regions. Each infusion and imaging session was followed by a standardized lunch. Compared with saline, the BOLD response to food aroma relative to a nonfood aroma in the hypothalamic area was greater during alcohol infusion, as was subsequent food intake. Despite inducing greater food intake, alcohol infusion decreased the appetite-stimulating gut hormone ghrelin. Together, these data indicate that the hypothalamus is a key site of action for alcohol-induced increases in food intake, although specific neurochemical signaling molecules require further study.

In addition to alcohol’s notorious calorie content (a hefty 7 calories per gram), this study provides another mechanism by which alcohol intake can contribute to weight gain. Although the findings will need to be replicated in men, the new work puts a damper on the joys of relaxing with an apéritif.

W. J. A. Eiler II et al., The apéritif effect: Alcohol’s effects on the brain’s response to food aromas in women. Obesity 23, 1386–1393 (2015). [Abstract]

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