Lanini Juliana, Galduróz José Carlos Fernandes, Pompéia Sabine
Departamento de Psicobiologia, Universidade Federal de São Paulo, Brazil.
Hum Psychopharmacol. 2016 Jan;31(1):29-43. doi: 10.1002/hup.2511. Epub 2015 Dec 1.
Caffeine is widely used, often consumed with food, and improves simple and complex/executive attention under fasting conditions. We investigated whether these cognitive effects are observed when personalized habitual doses of caffeine are ingested by caffeine consumers, whether they are influenced by nutriments and if various executive domains are susceptible to improvement. This was a double-blind, placebo-controlled study including 60 young, healthy, rested males randomly assigned to one of four treatments: placebo fasting, caffeine fasting, placebo meal and caffeine meal. Caffeine doses were individualized for each participant based on their self-reported caffeine consumption at the time of testing (morning). The test battery included measures of simple and sustained attention, executive domains (inhibiting, updating, shifting, dual tasking, planning and accessing long-term memory), control measures of subjective alterations, glucose and insulin levels, skin conductance, heart rate and pupil dilation. Regardless of meal intake, acute habitual doses of caffeine decreased fatigue, and improved simple and sustained attention and executive updating. This executive effect was not secondary to the habitual weekly dose consumed, changes in simple and sustained attention, mood, meal ingestion and increases in cognitive effort. We conclude that the morning caffeine "fix" has positive attentional effects and selectively improved executive updating whether or not caffeine is consumed with food.
咖啡因被广泛使用,常与食物一起摄入,并且在空腹条件下能改善简单注意力和复杂/执行性注意力。我们研究了咖啡因消费者摄入个性化习惯剂量的咖啡因时是否会出现这些认知效应,这些效应是否受营养物质影响,以及各个执行领域是否易于改善。这是一项双盲、安慰剂对照研究,纳入了60名年轻、健康、休息良好的男性,他们被随机分配到四种处理之一:安慰剂空腹组、咖啡因空腹组、安慰剂进餐组和咖啡因进餐组。根据每位参与者在测试时(早晨)自我报告的咖啡因摄入量为其个体化确定咖啡因剂量。测试项目包括简单和持续注意力测量、执行领域(抑制、更新、转换、双任务、计划和提取长期记忆)、主观改变的对照测量、血糖和胰岛素水平、皮肤电传导、心率和瞳孔扩张。无论进餐情况如何,急性习惯剂量的咖啡因均可减轻疲劳,并改善简单和持续注意力以及执行更新能力。这种执行效应并非继发于每周习惯摄入量、简单和持续注意力的变化、情绪、进餐摄入以及认知努力的增加。我们得出结论,无论咖啡因是否与食物一起摄入,早晨摄入咖啡因“提神”都具有积极的注意力效应,并能选择性地改善执行更新能力。