Reay Jonathon L, Kennedy David O, Scholey Andrew B
Human Cognitive Neuroscience Unit, Northumbria University, Newcastle upon Tyne, NE1 8ST, UK.
J Psychopharmacol. 2006 Nov;20(6):771-81. doi: 10.1177/0269881106061516. Epub 2006 Jan 9.
Single doses of the traditional herbal treatment Panax ginseng have recently been shown to lower blood glucose levels and elicit cognitive improvements in healthy, overnight-fasted volunteers. The specific mechanisms responsible for these effects are not known. However, cognitive improvements may be related to the glycaemic properties of Panax ginseng. Using a double-blind, placebo-controlled, balanced-crossover design, 27 healthy young adults completed a 10 minute "cognitive demand" test battery at baseline. They then consumed capsules containing either ginseng (extract G115) or a placebo and 30 minutes later a drink containing glucose or placebo. A further 30 minutes later (i.e. 60 minutes post-baseline/capsules) they completed the "cognitive demand" battery six times in immediate succession. Depending on the condition to which the participant was allocated on that particular day, the combination of capsules/drink treatments corresponded to a dose of: 0mg G115/0 mg glucose (placebo); 200mg G115/0 mg glucose (ginseng); 0 mg G115/25 g glucose (glucose) or 200 mg G115/25 g glucose (ginseng/glucose combination). The 10 minute "cognitive demand" battery comprised a Serial Threes subtraction task (2 min); a Serial Sevens subtraction task (2 min); a Rapid Visual Information Processing task (5 min); and a "mental fatigue" visual analogue scale. Blood glucose levels were measured prior to the day's treatment, and before and after the post-dose completions of the battery. The results showed that both Panax ginseng and glucose enhanced performance of a mental arithmetic task and ameliorated the increase in subjective feelings of mental fatigue experienced by participants during the later stages of the sustained, cognitively demanding task performance. Accuracy of performing the Rapid Visual Information Processing task (RVIP) was also improved following the glucose load. There was no evidence of a synergistic relationship between Panax ginseng and exogenous glucose ingestion on any cognitive outcome measure. Panax ginseng caused a reduction in blood glucose levels 1 hour following consumption when ingested without glucose. These results confirm that Panax ginseng may possess glucoregulatory properties and can enhance cognitive performance.
近期研究表明，单次服用传统草药人参可降低健康、过夜禁食志愿者的血糖水平，并改善其认知能力。这些作用的具体机制尚不清楚。然而，认知能力的改善可能与人参的血糖特性有关。采用双盲、安慰剂对照、平衡交叉设计，27名健康年轻成年人在基线时完成了一项10分钟的“认知需求”测试组。然后，他们服用含人参（提取物G115）或安慰剂的胶囊，30分钟后饮用含葡萄糖或安慰剂的饮料。再过30分钟（即基线/胶囊后60分钟），他们连续六次完成“认知需求”测试组。根据参与者在特定日期分配的情况，胶囊/饮料治疗组合对应于以下剂量：0mg G115/0mg葡萄糖（安慰剂）；200mg G115/0mg葡萄糖（人参）；0mg G115/25g葡萄糖（葡萄糖）或200mg G115/25g葡萄糖（人参/葡萄糖组合）。10分钟的“认知需求”测试组包括一个连续减三任务（2分钟）；一个连续减七任务（2分钟）；一个快速视觉信息处理任务（5分钟）；以及一个“精神疲劳”视觉模拟量表。在当天治疗前、测试组服药后完成前后测量血糖水平。结果表明，人参和葡萄糖均能提高心算任务的表现，并减轻参与者在持续的、认知要求高的任务后期所经历的主观精神疲劳感的增加。葡萄糖负荷后，快速视觉信息处理任务（RVIP）的执行准确性也有所提高。在任何认知结果测量中，均未发现人参与外源性葡萄糖摄入之间存在协同关系。在不摄入葡萄糖的情况下，人参摄入后1小时可导致血糖水平降低。这些结果证实，人参可能具有调节血糖的特性，并能提高认知表现。
