Effects of high-dose B vitamin complex with vitamin C and minerals on subjective mood and performance in healthy males

A significant proportion of the general population report supplementing their diet with one or more vitamins or minerals, with common reasons for doing so being to combat stress and fatigue and to improve mental functioning. Few studies have assessed the relationship between supplementation with vitamins/minerals and psychological functioning in healthy cohorts of non-elderly adults. The present randomised, placebo-controlled, double-blind, parallel groups trial assessed the cognitive and mood effects of a high-dose B-complex vitamin and mineral supplement (Berocca®) in 215 males aged 30 to 55 years, who were in full-time employment. Participants attended the laboratory prior to and on the last day of a 33-day treatment period where they completed the Profile of Mood States (POMS), Perceived Stress Scale (PSS) and General Health Questionnaire (GHQ-12). Cognitive performance and task-related modulation of mood/fatigue were assessed with the 60 min cognitive demand battery. On the final day, participants also completed the Stroop task for 40 min whilst engaged in inclined treadmill walking and subsequent executive function was assessed. Vitamin/mineral supplementation led to significant improvements in ratings on the PSS, GHQ-12 and the 'vigour' subscale of the POMS. The vitamin/mineral group also performed better on the Serial 3s subtractions task and rated themselves as less 'mentally tired' both pre- and post-completion of the cognitive demand battery. Healthy members of the general population may benefit from augmented levels of vitamins/minerals via direct dietary supplementation. Specifically, supplementation led to improved ratings of stress, mental health and vigour and improved cognitive performance during intense mental processing

The effects of chronic trans-resveratrol supplementation on aspects of cognitive function, mood, sleep, health and cerebral blood flow in healthy, young humans

Single doses of resveratrol have previously been shown to increase cerebral blood flow (CBF) with no clear effect on cognitive function or mood in healthy adults. Chronic resveratrol consumption may increase the poor bioavailability of resveratrol or otherwise potentiate its psychological effects. In this randomised, double-blind, placebo-controlled, parallel-groups study, a total of sixty adults aged between 18 and 30 years received either placebo or resveratrol for 28 d. On the 1st and 28th day of treatment, the performance of cognitively demanding tasks (serial subtractions, rapid visual information processing and 3-Back) (n 41 complete data sets) was assessed, alongside blood pressure (n 26) and acute (near-IR spectroscopy (NIRS)) and chronic (transcranial Doppler) measures of CBF (n 46). Subjective mood, sleep quality and health questionnaires were completed at weekly intervals (n 53/54). The results showed that the cognitive effects of resveratrol on day 1 were restricted to more accurate but slower serial subtraction task performance. The only cognitive finding on day 28 was a beneficial effect of resveratrol on the accuracy of the 3-Back task before treatment consumption. Subjective ratings of ‘fatigue’ were significantly lower across the entire 28 d in the resveratrol condition. Resveratrol also resulted in modulation of CBF parameters on day 1, as assessed by NIRS, and significantly increased diastolic blood pressure on day 28. Levels of resveratrol metabolites were significantly higher both before and after the day’s treatment on day 28, in comparison with day 1. These results confirm the acute CBF effects of resveratrol and the lack of interpretable cognitive effects

Cerebral blood flow and behavioural effects of caffeine in habitual and non-habitual consumers of caffeine: A near infrared spectroscopy study

Caffeine has been shown to modulate cerebral blood flow, with little evidence of tolerance to these effects following habitual use. However, previous studies have focused on caffeine levels much higher than those found in dietary servings and have compared high caffeine consumers with low consumers rather than 'non-consumers'. The current placebo-controlled double-blind, balanced-crossover study employed near infrared spectroscopy to monitor pre-frontal cerebral-haemodynamics at rest and during completion of tasks that activate the pre-frontal cortex. Twenty healthy young habitual and non-habitual consumers of caffeine received 75mg caffeine or placebo. Caffeine significantly decreased cerebral blood flow but this was subject to a significant interaction with consumption status, with no significant effect being shown in habitual consumers and an exaggerated effect in non-habitual consumers. These findings suggest that caffeine, at levels typically found in a single dietary serving, is able to modulate cerebral blood flow but these effects are subject to tolerance

Consumption of cocoa flavanols results in acute improvements in mood and cognitive performance during sustained mental effort

Cocoa flavanols (CF) positively influence physiological processes in ways that suggest their consumption may improve aspects of cognitive function. This study investigated the acute cognitive and subjective effects of CF consumption during sustained mental demand. In this randomized, controlled, double-blinded, balanced, three period crossover trial 30 healthy adults consumed drinks containing 520 mg, 994 mg CF and a matched control, with a three-day washout between drinks. Assessments included the state anxiety inventory and repeated 10-min cycles of a Cognitive Demand Battery comprising of two serial subtraction tasks (Serial Threes and Serial Sevens), a Rapid Visual Information Processing (RVIP) task and a mental fatigue scale, over the course of 1 h. Consumption of both 520 mg and 994 mg CF significantly improved Serial Threes performance. The 994 mg CF beverage significantly speeded RVIP responses but also resulted in more errors during Serial Sevens. Increases in self-reported mental fatigue were significantly attenuated by the consumption of the 520 mg CF beverage only. This is the first report of acute cognitive improvements following CF consumption in healthy adults. While the mechanisms underlying the effects are unknown they may be related to known effects of CF on endothelial function and blood flow

Effects of Valeriana officinalis on mood and physiological responses to a multi-tasking stressor

Valeriana officinalis (valerian) is a plant native to Europe that is widely used in the UK. Extracts of this plant have a long history of traditional use as sleep aids and anxiolytics and are subsequently a leading dietary supplement used in the self management of anxiety and insomnia. The majority of experimental research to date relates to Valerian as a treatment for insomnia. Although the evidence to date suggests that Valerian can improve sleep quality, the results are not conclusive. Research focusing on the putative effects of Valerian as an anxiolytic has largely been in conjunction with other herbal extracts and although positive anxiolytic effects were found, decrements in performance were also observed. It also remains unclear whether the observed improvements were following a combination of treatments or whether valerian alone has anxiolytic effects. The current study was therefore aimed at elucidating the anxiolytic effects of valerian extracts upon stress-related psychological and physiological parameters and aspects of performance

Improved cognitive performance in human volunteers following administration of guarana (Paullinia cupana) extract: comparison and interaction with Panax ginseng

Extracts from the plant guarana (Paullinia cupana) feature as putatively stimulating ingredients in a number of foods, drinks and dietary/herbal supplements. To date, little research in humans has examined the potential psychoactive effects of these extracts. Extracts of Panax ginseng, which are often sold in combination with guarana, contain similar potentially active components, and have been shown to modulate cognitive performance. In this double-blind, counterbalanced, placebo-controlled study, the cognitive and mood effects of separate single doses of: 75 mg of a dried ethanolic extract of guarana (approx 12% caffeine), 200 mg of Panax ginseng (G115), and their combination (75 mg/200 mg), were assessed in 28 healthy young (18-24) participants. On each day of the study (separated by a 7-day washout), cognitive performance and subjective mood were assessed pre-dose and at 1, 2.5, 4 and 6 h post-dose using the Cognitive Drug Research computerised assessment battery, Serial subtraction tasks and Bond-Lader mood scales. In comparison to placebo, all three treatments resulted in improved task performance throughout the day. In the case of guarana, improvements were seen across 'attention' tasks (but with some evidence of reduced accuracy), and on a sentence verification task. While also increasing the speed of attention task performance, both ginseng and the ginseng/guarana combination also enhanced the speed of memory task performance, with little evidence of modulated accuracy. Guarana and the combination, and to a lesser extent ginseng, also led to significant improvements in serial subtraction task performance. These results provide the first demonstration in humans of the psychoactive effects of guarana, and confirmation of the psychoactive properties of ginseng. Given the low caffeine content (9 mg) of this dose of guarana extract, the effects are unlikely to be attributable to its caffeine content

Cognitive and mood improvements of caffeine in habitual consumers and habitual non-consumers of caffeine

Rationale: The cognitive and mood effects of caffeine are well documented. However, the majority of studies in this area involve caffeine-deprived, habitual caffeine users. It is therefore unclear whether any beneficial findings are due to the positive effects of caffeine or to the alleviation of caffeine withdrawal. Objectives: The present placebo-controlled, double-blind, balanced crossover study investigated the acute cognitive and mood effects of caffeine in habitual users and habitual non-users of caffeine. Method: Following overnight caffeine withdrawal, 24 habitual caffeine consumers (mean=217 mg/day) and 24 habitual non-consumers (20 mg/day) received a 150 ml drink containing either 75 or 150 mg of caffeine or a matching placebo, at intervals of ≥ h. Cognitive and mood assessments were undertaken at baseline and 30 min post-drink. These included the Cognitive Drug Research computerised test battery, two serial subtraction tasks, a sentence verification task and subjective visual analogue mood scales. Results: There were no baseline differences between the groups' mood or performance. Following caffeine, there were significant improvements in simple reaction time, digit vigilance reaction time, numeric working memory reaction time and sentence verification accuracy, irrespective of group. Self-rated mental fatigue was reduced and ratings of alertness were significantly improved by caffeine independent of group. There were also group effects for rapid visual information processing false alarms and spatial memory accuracy with habitual consumers outperforming non-consumers. There was a single significant interaction of group and treatment effects on jittery ratings. Separate analyses of each groups' responses to caffeine revealed overlapping but differential responses to caffeine. Caffeine tended to benefit consumers' mood more while improving performance more in the non-consumers. Conclusions: These results do not support a withdrawal alleviation model. Differences in the patterns of responses to caffeine by habitual consumers and habitual non-consumers may go some way to explaining why some individuals become caffeine consumers

Monoterpenoid extract of sage (Salvia lavandulaefolia) with cholinesterase inhibiting properties improves cognitive performance and mood in healthy adults

Extracts of sage (Salvia officinalis/lavandulaefolia) with terpenoid constituents have previously been shown to inhibit cholinesterase and improve cognitive function. The current study combined an in vitro investigation of the cholinesterase inhibitory properties and phytochemical constituents of a S. lavandulaefolia essential oil, with a double-blind, placebo-controlled, balanced crossover study assessing the effects of a single dose on cognitive performance and mood. In this latter investigation 36 healthy participants received capsules containing either 50 µL of the essential oil or placebo on separate occasions, 7 days apart. Cognitive function was assessed using a selection of computerized memory and attention tasks and the Cognitive Demand Battery before the treatment and 1-h and 4-h post-dose. The essential oil was a potent inhibitor of human acetylcholinesterase (AChE) and consisted almost exclusively of monoterpenoids. Oral consumption lead to improved performance of secondary memory and attention tasks, most notably at the 1-h post-dose testing session, and reduced mental fatigue and increased alertness which were more pronounced 4-h post-dose. These results extend previous observations of improved cognitive performance and mood following AChE inhibitory sage extracts and suggest that the ability of well-tolerated terpenoid-containing extracts to beneficially modulate cholinergic function and cognitive performance deserves further attention