Department of Kinesiology, University of Georgia, Athens, Georgia 30602-6554, USA.
J Med Food. 2013 Aug;16(8):765-71. doi: 10.1089/jmf.2012.0216. Epub 2013 Aug 1.
The purpose was to test whether a single dose of black pepper or rosemary produced short-term enhancements in sustained attention, motivation to perform cognitive tasks, or feelings of mental energy and fatigue. Outcomes were measured in 40 young adults with below average feelings of energy before and twice after they orally consumed capsules containing either black pepper (2.0 g), rosemary (1.7 g), or a placebo (3.1 g rice flour). Sustained attention was measured using a 16-min dual task, in which, single-digit numbers were presented every second on a screen and the participant performed both a primary task [detection of three successive, different odd digits] and a secondary task [detection of the number 6]. Feelings of energy and fatigue were measured using the vigor and fatigue subscales of the Profile of Mood States and visual analog scales (VAS). Analysis of variance showed nonsignificant condition (spice versus placebo)×time (T1, T2, & T3) effects for motivation, measured with a VAS, and the intensity of energy and fatigue feelings. Unadjusted effect sizes revealed that rosemary induced small, transient reductions in false alarm errors (d=0.21) and mental fatigue (d=0.40) at isolated time periods. Time-varying analysis of covariance, controlling for motivation to perform cognitive tasks, showed no significant effects on the primary or secondary task outcomes of correct responses (hits), errors (false alarms, misses), speed of response (reaction time), and signal detection sensitivity. It is concluded that black pepper and rosemary, consumed in a capsule form, in the doses used and while wearing a nose clip to block olfactory effects, do not induce consistent short-term improvements in sustained attention, motivation to perform cognitive tasks, or feelings of mental energy and fatigue in young adults with low energy.
目的是测试黑胡椒或迷迭香单一剂量是否能在短期内提高持续注意力、完成认知任务的动力，或提高精神能量和疲劳感。40 名精力水平低于平均水平的年轻人在口服含有黑胡椒（2.0 克）、迷迭香（1.7 克）或安慰剂（3.1 克米粉）胶囊前后两次分别测量了持续注意力、能量和疲劳感。使用 16 分钟的双重任务来测量持续注意力，在屏幕上每隔一秒显示一位数字，参与者需要同时完成一项主要任务（检测连续三个不同的奇数）和一项次要任务（检测数字 6）。使用心境状态问卷的活力和疲劳分量表以及视觉模拟量表（VAS）来测量能量和疲劳感。方差分析显示，在动机（用 VAS 测量）以及能量和疲劳感的强度方面，实验组（香料组）和对照组（安慰剂组）之间的条件（香料与安慰剂）×时间（T1、T2 和 T3）没有显著差异。未调整的效应大小显示，迷迭香在孤立的时间段内引起了较小的、短暂的错误警报错误（d=0.21）和精神疲劳（d=0.40）减少。在控制完成认知任务的动力的协方差时间变化分析中，对正确反应（命中）、错误（错误警报、漏报）、反应速度（反应时间）和信号检测灵敏度的主要和次要任务结果没有显示出显著影响。结论是，黑胡椒和迷迭香以胶囊形式服用，剂量适中，同时佩戴鼻夹以阻断嗅觉效应，在精力水平较低的年轻人中，不会在持续注意力、完成认知任务的动力或精神能量和疲劳感方面持续产生短期改善。
