Burger Kyle S
Department of Nutrition, Gillings School of Global Public Health, and Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, NC
Am J Clin Nutr. 2017 Mar;105(3):555-563. doi: 10.3945/ajcn.116.140145. Epub 2017 Feb 8.
Current obesity theories suggest that the repeated intake of highly palatable high-sugar foods causes adaptions in the striatum, parietal lobe, and prefrontal and visual cortices in the brain that may serve to perpetuate consumption in a feed-forward manner. However, the data for humans are cross-sectional and observational, leaving little ability to determine the temporal precedence of repeated consumption on brain response. We tested the impact of regular sugar-sweetened beverage intake on brain and behavioral responses to beverage stimuli. We performed an experiment with 20 healthy-weight individuals who were randomly assigned to consume 1 of 2 sugar-sweetened beverages daily for 21 d, underwent 2 functional MRI sessions, and completed behavioral and explicit hedonic assessments. Consistent with preclinical experiments, daily beverage consumption resulted in decreases in dorsal striatal response during receipt of the consumed beverage ( = -0.46) and decreased ventromedial prefrontal response during logo-elicited anticipation ( = -0.44). This decrease in the prefrontal response correlated with increases in behavioral disinhibition toward the logo of the consumed beverage ( = 0.54; = 0.02). Daily beverage consumption also increased precuneus response to both juice logos compared with a tasteless control ( = 0.45), suggesting a more generalized effect toward beverage cues. Last, the repeated consumption of 1 beverage resulted in an explicit hedonic devaluation of a similar nonconsumed beverage ( < 0.001). Analogous to previous reports, these initial results provide convergent data for a role of regular sugar-sweetened beverage intake in altering neurobehavioral responses to the regularly consumed beverage that may also extend to other beverage stimuli. Future research is required to provide evidence of replication in a larger sample and to establish whether the neurobehavioral adaptations observed herein are specific to high-sugar and/or nonnutritive-sweetened beverages or more generally related to the repeated consumption of any type of food. This trial was registered at clinicaltrials.gov as NCT02624206.
当前的肥胖理论表明，反复摄入高美味的高糖食物会导致大脑纹状体、顶叶、前额叶和视觉皮层发生适应性变化，这些变化可能以前馈方式促使进食行为持续下去。然而，有关人类的数据是横断面的且为观察性数据，几乎无法确定反复进食在时间上先于大脑反应。我们测试了定期摄入含糖饮料对大脑及对饮料刺激的行为反应的影响。我们对20名体重正常的个体进行了一项实验，他们被随机分配，连续21天每天饮用两种含糖饮料中的一种，接受两次功能性磁共振成像扫描，并完成行为和明确的享乐评估。与临床前实验一致，每日饮用饮料导致在饮用所消费饮料期间背侧纹状体反应降低（= -0.46），在标识引发的预期期间腹内侧前额叶反应降低（= -0.44）。前额叶反应的这种降低与对所消费饮料标识的行为去抑制增加相关（= 0.54；= 0.02）。与无味对照相比，每日饮用饮料还增加了楔前叶对两种果汁标识的反应（= 0.45），表明对饮料线索有更广泛的影响。最后，反复饮用一种饮料导致对类似的未消费饮料出现明确的享乐贬值（< 0.001）。与之前的报告类似，这些初步结果为定期摄入含糖饮料在改变对经常饮用饮料的神经行为反应中的作用提供了趋同数据，这种作用可能也扩展到其他饮料刺激。未来的研究需要提供在更大样本中重复实验的证据，并确定本文观察到的神经行为适应性变化是否特定于高糖和/或非营养甜味饮料，还是更普遍地与任何类型食物的反复消费有关。该试验已在clinicaltrials.gov上注册，注册号为NCT02624206。
