Lin Yu-Shiuan, Weibel Janine, Landolt Hans-Peter, Santini Francesco, Garbazza Corrado, Kistler Joshua, Rehm Sophia, Rentsch Katharina, Borgwardt Stefan, Cajochen Christian, Reichert Carolin F
Centre for Chronobiology, University Psychiatric Clinics Basel, Basel, Switzerland.
Transfaculty Research Platform Molecular and Cognitive Neurosciences, University of Basel, Basel, Switzerland.
Front Nutr. 2022 Feb 2;8:787225. doi: 10.3389/fnut.2021.787225. eCollection 2021.
Caffeine elicits widespread effects in the central nervous system and is the most frequently consumed psychostimulant worldwide. First evidence indicates that, during daily intake, the elimination of caffeine may slow down, and the primary metabolite, paraxanthine, may accumulate. The neural impact of such adaptions is virtually unexplored. In this report, we leveraged the data of a laboratory study with = 20 participants and three within-subject conditions: caffeine (150 mg caffeine × 3/day × 10 days), placebo (150 mg mannitol × 3/day × 10 days), and acute caffeine deprivation (caffeine × 9 days, afterward placebo × 1 day). On day 10, we determined the course of salivary caffeine and paraxanthine using liquid chromatography-mass spectrometry coupled with tandem mass spectrometry. We assessed gray matter (GM) intensity and cerebral blood flow (CBF) after acute caffeine deprivation as compared to changes in the caffeine condition from our previous report. The results indicated that levels of paraxanthine and caffeine remained high and were carried overnight during daily intake, and that the levels of paraxanthine remained elevated after 24 h of caffeine deprivation compared to placebo. After 36 h of caffeine deprivation, the previously reported caffeine-induced GM reduction was partially mitigated, while CBF was elevated compared to placebo. Our findings unveil that conventional daily caffeine intake does not provide sufficient time to clear up psychoactive compounds and restore cerebral responses, even after 36 h of abstinence. They also suggest investigating the consequences of a paraxanthine accumulation during daily caffeine intake.
咖啡因在中枢神经系统中会引发广泛影响，是全球消费最为频繁的精神兴奋剂。初步证据表明，在日常摄入过程中，咖啡因的消除可能会减缓，其主要代谢产物副黄嘌呤可能会积累。而这种适应性变化对神经的影响几乎尚未得到探索。在本报告中，我们利用了一项实验室研究的数据，该研究有20名参与者，设置了三种受试者内条件：咖啡因组（150毫克咖啡因×每日3次×10天）、安慰剂组（150毫克甘露醇×每日3次×10天）以及急性咖啡因戒断组（咖啡因摄入9天，之后服用1天安慰剂）。在第10天，我们使用液相色谱 - 质谱联用串联质谱法测定唾液中咖啡因和副黄嘌呤的含量。与我们之前报告中咖啡因条件下的变化相比，我们评估了急性咖啡因戒断后的灰质（GM）强度和脑血流量（CBF）。结果表明，在日常摄入期间，副黄嘌呤和咖啡因的水平一直很高且会持续到夜间，并且与安慰剂相比，在咖啡因戒断24小时后副黄嘌呤水平仍然升高。在咖啡因戒断36小时后，之前报告的咖啡因引起的灰质减少部分得到缓解，而与安慰剂相比脑血流量升高。我们的研究结果表明，即使在戒断36小时后，常规的每日咖啡因摄入量也没有提供足够的时间来清除精神活性化合物并恢复大脑反应。它们还建议研究日常咖啡因摄入期间副黄嘌呤积累的后果。
