2023-03-22 マックス・プランク研究所
この研究において、参加者の一部に高脂肪・高糖分のプリンを毎日8週間与え、脳活動を計測した。その結果、この食品を食べるグループの脳は、報酬・動機づけを担当するドーパミン神経系を特に活性化させた。また、血糖値やコレステロールなどの血液値は変化しなかったが、プリンを食べたグループの脳の反応は大幅に増加した。
研究者は、このようにして脳は報酬性のある食品を好むように学習すると考えている。研究者たちは、この嗜好が研究後も続く可能性があるとしている。
<関連情報>
- https://www.mpg.de/20024294/0320-neur-sweets-change-our-brain-153735-x
- https://www.sciencedirect.com/science/article/pii/S1550413123000517
甘くて脂肪分の多いスナックの習慣的な毎日の摂取は、ヒトの報酬処理を変調させる Habitual daily intake of a sweet and fatty snack modulates reward processing in humans
Sharmili Edwin Thanarajah, Alexandra G. DiFeliceantonio, Kerstin Albus, Bojana Kuzmanovic, Lionel Rigoux, Sandra Iglesias, Ruth Hanßen, Marc Schlamann, Oliver A. Cornely, Jens C. Brüning, Marc Tittgemeyer, Dana M. Small
Cell Metabolism Published: March 22, 2023
DOI:https://doi.org/10.1016/j.cmet.2023.02.015
Highlights
- •Daily consumption of a high-fat/high-sugar snack alters reward circuits in humans
- •Preference for low-fat food decreases while brain response to milkshake increases
- •Neural computations that support adaptive associative learning are also enhanced
- •Effects are observed despite no change in body weight or metabolic health
Summary
Western diets rich in fat and sugar promote excess calorie intake and weight gain; however, the underlying mechanisms are unclear. Despite a well-documented association between obesity and altered brain dopamine function, it remains elusive whether these alterations are (1) pre-existing, increasing the individual susceptibility to weight gain, (2) secondary to obesity, or (3) directly attributable to repeated exposure to western diet. To close this gap, we performed a randomized, controlled study (NCT05574660) with normal-weight participants exposed to a high-fat/high-sugar snack or a low-fat/low-sugar snack for 8 weeks in addition to their regular diet. The high-fat/high-sugar intervention decreased the preference for low-fat food while increasing brain response to food and associative learning independent of food cues or reward. These alterations were independent of changes in body weight and metabolic parameters, indicating a direct effect of high-fat, high-sugar foods on neurobehavioral adaptations that may increase the risk for overeating and weight gain.
