When should the driver with a history of substance misuse be allowed to return to the wheel? A review of the substance misuse section of the Australian national guidelines.

Assessing fitness to drive in applicants with a historical or current substance use disorder presents a specific clinical challenge. The Australian guidelines require evidence of remission and absence of cognitive change when considering applications for re-licensing driver or individuals applying to reengage in safety-sensitive work. This paper reviews some of the clinical and biochemical indicators that determine whether a particular person is in 'remission' and meets the criteria for return to driving or other safety-sensitive occupation. It provides an overview of the challenges in establishing an evidence-based approach to determining fitness for safety critical activities. There is no internationally accepted definition of 'remission'. Review of the literature and examination of assessment protocols from other national jurisdictions are available for alcohol and the more important drugs of interest in road safety. Assessing fitness to drive when there is a history of substance misuse and/or substance use disorders is a complex issue that requires assessment of biomarkers, clinical findings and clinical assessment before the person returns to driving. We propose that hair testing provides a reliable and reproducible way to demonstrate remission and provide cost-effective monitoring. Standardised psychological tests could provide a reproducible assessment of the cognitive effects of drug use and suitability to resume driving. We recommend that AustRoads amend the national guidelines to reflect an evidence-based approach to assessing fitness to drive after conviction for offences related to alcohol and drug use.

Relationships Among Cognitive Function and Cerebral Blood Flow, Oxidative Stress, and Inflammation in Older Heart Failure Patients.

BACKGROUND: The mechanisms for cognitive impairment in heart failure (HF) are unclear. We investigated the relative contributions of cerebral blood flow velocity (BFV), oxidative stress, and inflammation to HF-associated cognitive impairment. METHODS AND RESULTS: Thirty-six HF patients (≥60 years) and 40 healthy controls (68 ± 7 vs 67 ± 5 years, P > .05; 69% vs 50% male, P > .05) completed the Cognitive Drug Research computerized assessment battery and Stroop tasks. Common carotid (CCA) and middle cerebral arterial BFV were obtained by transcranial Doppler. Blood samples were collected for oxidant (diacron-reactive oxygen metabolites; F2-isoprostanes), antioxidant (coenzyme Q10; CoQ10), and inflammatory markers (high-sensitivity C-reactive protein). Compared with controls, patients exhibited impaired attention (Cognitive Drug Research's Power of Attention domain, congruent Stroop) and executive function (incongruent Stroop). Multiple regression modeling showed that CCA-BFV and CoQ10 but not group predicted performance on attention and executive function. Additionally, in HF patients, CCA-BFV and CoQ10 (ß = -0.34 vs ß = -0.35) were significant predictors of attention, and CCA-BFV (ß = -0.34) was a predictor of executive function. CONCLUSIONS: Power of Attention and executive function is impaired in older HF patients, and reduced CCA-BFV and CoQ10 are associated with worse cognition. Interventions addressing these mechanisms may improve cognition in older HF patients.

The effect of Sailuotong (SLT) on neurocognitive and cardiovascular function in healthy adults: a randomised, double-blind, placebo controlled crossover pilot trial.

BACKGROUND: Sailuotong (SLT) is a standardised herbal medicine formula consisting of Panax ginseng, Ginkgo biloba, and Crocus sativus, and has been designed to enhance cognitive and cardiovascular function. METHODS: Using a randomised, double-blind, placebo controlled crossover design, this pilot study assessed the effect of treatment for 1 week with SLT and placebo (1 week washout period) on neurocognitive and cardiovascular function in healthy adults. Sixteen adults completed a computerised neuropsychological test battery (Compass), and had their electroencephalographic (EEG) activity and cardiovascular system function assessed. Primary outcome measures were cognitive test scores and oddball task event-related potential (ERP) component amplitudes. Secondary outcome measures were resting EEG spectral band amplitudes, and cardiovascular parameters. RESULTS: Treatment with SLT, compared to placebo, resulted in small improvements in working memory, a slight increase in auditory target (cf. nontarget) P3a amplitude, and a decrease in auditory N1 target (cf. nontarget) amplitude. There was no effect of SLT on EEG amplitude in delta, theta, alpha, or beta bands in both eyes open and eyes closed resting conditions, or on aortic and peripheral pulse pressure, and resting heartrate. CONCLUSIONS: Findings suggest that SLT has the potential to improve working memory performance in healthy adults; a larger sample size is needed to confirm this. TRIAL REGISTRATION: Australia New Zealand Clinical Trials Registry Trial Registration Id: ACTRN12610000947000 .

A randomised controlled trial investigating the effects of Mediterranean diet and aerobic exercise on cognition in cognitively healthy older people living independently within aged care facilities: the Lifestyle Intervention in Independent Living Aged Care (LIILAC) study protocol [ACTRN12614001133628].

BACKGROUND: The rapid ageing of the population is becoming an area of great concern, both globally and in Australia. On a societal level, the cost of supporting an ageing demographic, particularly with their associated medical requirements, is becoming an ever increasing burden that is only predicted to rise in the foreseeable future. The progressive decline in individuals' cognitive ability as they age, particularly with respect to the ever increasing incidence of Alzheimer's Disease (AD) and other cognitive complications, is in many respects one of the foundation stones of these concerns. There have been numerous observational studies reporting on the positive effects that aerobic exercise and the Mediterranean diet appear to have on improving cognitive ability. However, the ability of such interventions to improve cognitive ability, or even reduce the rate of cognitive ageing, has not been fully examined by substantial interventional studies within an ageing population. METHODS: The LIILAC trial will investigate the potential for cognitive change in a cohort of cognitively healthy individuals, between the ages of 60 and 90 years, living in independent accommodation within Australian aged care facilities. This four-arm trial will investigate the cognitive changes which may occur as a result of the introduction of aerobic exercise and/or Mediterranean diet into individuals' lifestyles, as well as the mechanisms by which these changes may be occurring. Participants will be tested at baseline and 6 months on a battery of computer based cognitive assessments, together with cardiovascular and blood biomarker assessments. The cardiovascular measures will assess changes in arterial stiffness and central pulse pressures, while the blood measures will examine changes in metabolic profiles, including brain derived neurotrophic factor (BDNF), inflammatory factors and insulin sensitivity. CONCLUSION: It is hypothesised that exercise and Mediterranean diet interventions, both individually and in combination, will result in improvements in cognitive performance compared with controls. Positive findings in this research will have potential implications for the management of aged care, particularly in respect to reducing the rate of cognitive decline and the associated impacts both on the individual and the broader community. TRIAL REGISTRATION: Australia New Zealand Clinical Trial Registry- ACTRN12614001133628.

MDMA, cortisol, and heightened stress in recreational ecstasy users.

Stress develops when an organism requires additional metabolic resources to cope with demanding situations. This review will debate how recreational 3,4-methylenedioxymethamphetamine (MDMA, 'ecstasy') can increase some aspects of acute and chronic stress in humans. Laboratory studies on the acute effects of MDMA on cortisol release and neurohormone levels in drug-free regular ecstasy/MDMA users have been reviewed, and the role of the hypothalamic-pituitary-adrenal (HPA) axis in chronic changes in anxiety, stress, and cognitive coping is debated. In the laboratory, acute ecstasy/MDMA use can increase cortisol levels by 100-200%, whereas ecstasy/MDMA-using dance clubbers experience an 800% increase in cortisol levels, because of the combined effects of the stimulant drug and dancing. Three-month hair samples of abstinent users revealed cortisol levels 400% higher than those in controls. Chronic users show heightened cortisol release in stressful environments and deficits in complex neurocognitive tasks. Event-related evoked response potential studies show altered patterns of brain activation, suggestive of increased mental effort, during basic information processing. Chronic mood deficits include more daily stress and higher depression in susceptible individuals. We conclude that ecstasy/MDMA increases cortisol levels acutely and subchronically and that changes in the HPA axis may explain why recreational ecstasy/MDMA users show various aspects of neuropsychobiological stress.

Effects of multivitamin, mineral and herbal supplement on cognition in younger adults and the contribution of B group vitamins.

OBJECTIVE: Cognitive benefits of multivitamins have been observed in the elderly, but fewer trials have investigated younger, healthy cohorts. This randomised, double-blind, placebo-controlled study investigated the cognitive effects of 16-week multivitamin supplementation in adults aged 20-49 years. METHOD: A total of 138 participants aged 20-50 years were randomised and 116 completed the trial. The participants completed a computerised battery of cognitive tasks before and after 16-week supplementation with a multivitamin containing minerals and herbs or placebo. Blood measures of homocysteine, vitamin B6, B12 and folate were collected at both time points. RESULTS: In men, there was a strong trend (p = 0.01; which did not reach significance when adjusted for multiple comparisons) for the multivitamin to improve performance on the incongruent stroop task, a measure of selective attention and response inhibition. There were no cognitive benefits of multivitamin supplements in women. Multivitamin supplementation substantially increased blood levels of vitamin B6, B12 and folate in both genders and decreased homocysteine in men. In men who received the multivitamin, improved stroop congruent performance was associated with increased vitamin B6 levels. CONCLUSION: Multivitamin supplementation may be useful for maintaining levels of B vitamins. The effects of multivitamins on speeded attention such as the stroop task in young adults warrant further investigation.

Blood pressure and cognitive function: the role of central aortic and brachial pressures.

Central (aortic) blood pressures differ from brachial pressures and may be more relevant to the study of cognitive function, given that blood is delivered to the brain through the central large arteries. Pulse-pressure amplification reflects the augmentation of blood pressure between the central and peripheral arteries, which diminishes with aging. We aimed to determine the association between central blood pressure and cognitive function in independently living adults aged 20 to 82 years (N = 493). In adjusted regression models, higher central systolic pressure and higher central pulse pressure were each associated with poorer processing speed, Stroop processing, and recognition memory. Lower amplification was associated with poorer Stroop processing, working memory, and recognition memory. Higher brachial systolic pressure and brachial pulse pressure were both associated with poorer Stroop processing. In summary, central pressures and amplification were sensitive indicators of cognitive aging, predicting aspects of cognitive performance not predicted by brachial blood pressure.

No effect of 12 weeks' supplementation with 1 g DHA-rich or EPA-rich fish oil on cognitive function or mood in healthy young adults aged 18-35 years.

The n-3 PUFA are a unique class of fatty acids that cannot be manufactured by the body, and must be acquired via dietary sources. In the UK, as well as in other Western nations, these 'essential' fatty acids are consumed in quantities that fall below government guidelines. The present study explored the effects of 12 weeks' dietary supplementation with 1 g/d of two types of fish oil (FO; DHA-rich and EPA-rich) in 159 healthy young adults aged 18-35 years. An assessment of performance on a battery of computerised cognitive tasks and mood measures took place before and following the 12-week treatment regimen. Venous blood samples were also supplied by participants at both time points which were later analysed for serum fatty acid concentrations. Despite good adherence to the study protocol - as reflected in increased concentrations of n-3 serum fatty acids - compared with placebo, the observed effects of both active treatments were minimal. The only finding of note revealed that supplementation with EPA-rich FO may reduce subjective mental fatigue at times of high cognitive demand, although further investigation is required. These findings, taken together with other recent reports of null effects, suggest that dietary supplementation with n-3 PUFA in healthy, normally developing and impairment-free populations is unlikely to result in cognitive enhancement.

DHA-rich oil modulates the cerebral haemodynamic response to cognitive tasks in healthy young adults: a near IR spectroscopy pilot study.

The impact of dietary n-3 PUFA on behavioural outcomes has been widely researched; however, very little attention has been given to their impact on brain functioning in physiological terms. A total of twenty-two healthy adults took part in this double-blind, placebo-controlled study, wherein the cerebral haemodynamic effects of 12 weeks of daily dietary supplementation with either 1 g DHA-rich or 1 g EPA-rich fish oil (FO) or placebo (1 g olive oil) were assessed. Relative changes in the concentration of oxygenated Hb (oxy-Hb) and deoxygenated Hb were assessed in the prefrontal cortex using near IR spectroscopy (NIRS) during the performance of four computerised cognitive tasks. Supplementation with DHA-rich FO, in comparison with placebo, resulted in a significant increase in the concentrations of oxy-Hb and total levels of Hb, indicative of increased cerebral blood flow (CBF), during the cognitive tasks. In comparison, no effect on CBF was observed following supplementation with EPA-rich FO, where concentration changes in the chromophores followed the same pattern as placebo. These encouraging pilot data warrant further application of NIRS in this area.

The effects of multitasking on psychological stress reactivity in recreational users of cannabis and MDMA.

BACKGROUND: Cannabis and 3,4-methylenedioxymethamphetamine (MDMA) use is associated with psychobiological and neurocognitive deficits. Assessments of the latter typically include tests of memory and everyday cognitive functioning. However, to date, little attention has been paid to effects of drug use on psychological stress reactivity. We report three studies examining the effects of recreational use of cannabis and MDMA on mood and psychological responses to multitasking using a cognitively demanding laboratory stressor that provides an analogue for everyday situations involving responses to multiple stimuli. METHODS: The effects of the multitasking framework on mood and perceived workload were assessed in cannabis (N=25), younger (N=18) and older (N=20) MDMA users and compared with non-target drug controls. RESULTS: Compared with respective control groups, cannabis users became less alert and content, and both MDMA groups became less calm following acute stress. Unexpectedly, the stressor increased ratings of calm in cannabis users. Users also scored higher than their controls with respect to ratings of resources needed to complete the multitasking framework. CONCLUSIONS: These findings show, for the first time, that recreational use of cannabis and MDMA, beyond the period of intoxication, can negatively influence psychological responses to a multitasking stressor, and this may have implications for real-life situations which place high demands on cognitive resources.

A randomized controlled trial investigating the effect of Pycnogenol and Bacopa CDRI08 herbal medicines on cognitive, cardiovascular, and biochemical functioning in cognitively healthy elderly people: the Australian Research Council Longevity Intervention (ARCLI) study protocol (ANZCTR12611000487910).

BACKGROUND: One of the major challenges associated with our ageing population is the increasing incidence of age-associated cognitive decline, which has significant implications for an individual's ability to lead a productive and fulfilling life. In pure economic terms the costs of ageing reflects decreased productivity and engagement with the workforce. The maintenance of brain health underpinning intact cognition is a key factor to maintaining a positive, engaged, and productive lifestyle. In light of this, the role of diet, including supplementation with nutritional and even pharmacological interventions capable of ameliorating the neurocognitive changes that occur with age constitute vital areas of research. METHODS: In order to reduce cognitive ageing, the ARC longevity intervention (ARCLI) was developed to examine the effects of two promising natural pharmacologically active supplements on cognitive performance. ARCLI is a randomized, placebo-controlled, double-blind, 3-arm clinical trial in which 465 participants will be randomized to receive an extract of Bacopa monnieri (CDRI08 300 mg/day), Pycnogenol (150 mg/day), or placebo daily for 12 months. Participants will be tested at baseline and then at 3, 6 and 12 months post-randomization on a wide battery of cognitive, neuropsychological and mood measures, cardiovascular (brachial and aortic systolic and diastolic blood pressures as well as arterial stiffness), biochemical (assays to measure inflammation, oxidative stress and safety) as well as genetic assessments (telomere length and several Single Nucleotide Polymorphisms). The primary aim is to investigate the effects of these supplements on cognitive performance. The secondary aims are to explore the time-course of cognitive enhancement as well as potential cardiovascular and biochemical mechanisms underpinning cognitive enhancement over the 12 months of administration.ARCLI will represent one of the largest and most comprehensive experimental clinical trials in which supplements are administered to elderly participants. Results from ARCLI may help develop novel preventative health practices and nutritional/pharmacological targets in the elderly for cognitive and brain health. TRIAL REGISTRATION: Australia and New Zealand Clinical Trials Register (ANZCTR): ACTRN12611000487910.

Homocysteine Modulates Brain Functional Connectivity in a Memory Retrieval Task.

BACKGROUND: Homocysteine, a methionine metabolite, is a recognized risk factor for accelerated age-related cognitive decline and dementia. OBJECTIVE: In the light of studies indicating increases in brain activity and brain functional connectivity in the early stages of age-related cognitive decline, we undertook a study to examine the relationship between plasma homocysteine levels and brain functional connectivity in a group of late middle-aged males at risk of cognitive decline due to high body mass index and a sedentary lifestyle. METHODS: Brain functional connectivity was measured using the steady state visual evoked potential event related partial coherence while 38 participants performed a memory task where each trial comprised an object recognition task followed by a location memory task. RESULTS: We observed a significant transient peak in the correlation between plasma homocysteine levels and fronto-parietal brain functional connectivity immediately before the presentation of the memory location component of the task. Significantly, this correlation was only apparent if the participant pool included individuals with homocysteine concentrations above 11µmole/L. CONCLUSION: Our findings suggest that the increased brain functional connectivity observed in the earlier stages of age-related cognitive decline reflects pathognomonic changes in brain function and not compensatory changes engaged to enhance task performance. Our findings also suggest that homocysteine interferes with the inhibition of cortical networks where this inhibition is necessary for optimum task performance. Finally, we observed that the effect of homocysteine on brain functional connectivity is only apparent at concentrations above 11µmol/L.

Dairy constituents and neurocognitive health in ageing.

Age-related cognitive decline (ARCD) and dementia are of increasing concern to an ageing population. In recent years, there has been considerable research focused on effective dietary interventions that may prevent or ameliorate ARCD and dementia. While a number of studies have considered the impact that dairy products may have on physiological health, particularly with regard to the metabolic syndrome and cardiovascular health, further research is currently needed in order to establish the impact that dairy products have in the promotion of healthy brain function during ageing. The present review considers the available evidence for the positive effects of dairy products on the metabolic syndrome and glucose regulation, with consideration of the implications for neurocognitive health. A literature search of current (September 2010) meta-analyses/reviews and original research regarding dairy products and cognition was conducted through SCOPUS using the following search terms for dairy consituents: dairy, milk, cheese, yoghurt, probiotics, whey protein, alpha lactalbumin, calcium, B-12, bioactive peptides and colostrinin (CLN). These search terms for dairy products were combined with the following search terms related to cognition and health: cognition, cognitive decline, dementia, Alzheimer's disease, metabolic syndrome, diabetes, insulin resistance and glucose regulation. Concerns regarding SFA and other fatty acids found in dairy products are also reviewed in relation to different forms of dairy products. The review also considers recent evidence for positive neurocognitive effects associated with bioactive peptides, CLN and proline-rich polypeptides, α-lactalbumin, vitamin B12, calcium and probiotics. Future directions for the extraction and purification of beneficial constituents are also discussed. It is concluded that low-fat dairy products, when consumed regularly as part of a balanced diet, may have a number of beneficial outcomes for neurocognitive health during ageing.

The effect of multivitamin supplementation on mood and stress in healthy older men.

OBJECTIVE: There is a demonstrated association between poor mood and deficiency in several micronutrients. Multivitamin supplements contain a wide range of nutrients, suggesting that they may be effective in improving mood; however, few studies have investigated this potential in randomized, controlled trials. This study investigates the effects of a multivitamin, mineral, and herbal supplement on mood and stress in a group of healthy, older male volunteers. METHODS: In this randomized, double-blind, placebo-controlled trial, fifty men, aged 50-69 years, supplemented for a period of 8 weeks with a multivitamin formulation that contained vitamins (at levels above recommended daily intakes), minerals, antioxidants, and herbal extracts, or a placebo. They completed a series of mood and stress questionnaires at baseline and post-supplementation. RESULTS: Compared with placebo, there was a significant reduction in the overall score on a depression anxiety and stress scale and an improvement in alertness and general daily functioning in the multivitamin group. CONCLUSIONS: Supplementation with a multivitamin, mineral and herbal formulation may be useful in improving alertness and reducing negative mood symptoms and may also improve feelings of general day-to-day well-being.

Panax ginseng (G115) improves aspects of working memory performance and subjective ratings of calmness in healthy young adults.

OBJECTIVE: There is a lack of research into the cognitive and mood effects of repeated ginseng ingestion. The present study assessed the effects of Panax ginseng (G115) on subjective mood and aspects of 'working' memory processes, following a single dose and following sub-chronic (7 days) ingestion, in healthy volunteers. METHODS: A placebo-controlled, double-blind, randomised, crossover was utilised. Thirty volunteers (mean age 22.87 years; SD 4.01) received each treatment (200 mg; 400 mg; placebo) for 8 days, in a counter balanced order, with a 6-day wash-out period. Testing was on days 1 and 8 of each treatment period, at pre-dose, 1, 2.5 and 4 h post-dose. RESULTS: Results revealed dose-related treatment effects (p < 0.05). Two hundred milligrams slowed a fall in mood at 2.5 and 4 h on day 1 and at 1 and 4 h on day 8, but slowed responding on a mental arithmetic task across day 1 and at 1 and 2.5 h on day 8. The 400 mg dose also improved calmness (restricted 2.5 and 4 h on day 1) and improved mental arithmetic across days 1 and 8. CONCLUSIONS: We found no evidence of additional benefits, nor attenuation of acute effects following repeated ingestion of Panax ginseng (G115).

A short self-report measure of problems with executive function suitable for administration via the Internet.

This article describes a short self-report measure of problems with executive function designed for use in Internet-mediated research. In Study 1, participants completed the online measure (Webexec) using a browser but under laboratory conditions. They also completed a paper self-report measure of executive problems (the Dysexecutive Questionnaire; DEX) and three objective tasks involving executive function: reverse digit span, semantic fluency (unconstrained), and semantic fluency (constrained). Webexec scores correlated positively with the DEX and negatively with the three executive tasks. Further evidence of construct validity came from Study 2, in which Webexec scores correlated positively with both use of cannabis and prospective memory problems reported in an online drug questionnaire. Webexec thus appears suitable for online research with normal populations.

Findings of a Pilot Study Investigating the Effects of Mediterranean Diet and Aerobic Exercise on Cognition in Cognitively Healthy Older People Living Independently within Aged-Care Facilities: The Lifestyle Intervention in Independent Living Aged Care (LIILAC) Study.

BACKGROUND: Cognitive decline and Alzheimer disease are more prevalent in our aging population. Modifiable risk factors, such as diet and sedentary lifestyle, have been proposed as key to potentially ameliorating cognitive decline. Both exercise and Mediterranean diet (MedDiet) have been linked to reduced levels of cardiovascular disease and other comorbidities. Higher levels of exercise and MedDiet adherence may prove to be cognitively protective, both individually and synergistically. OBJECTIVES: The aim was to investigate the effect of a 6-mo program of MedDiet, exercise, and a combination of both, on cognition, mood, and general health in older persons living independently in aged-care communities. METHODS: The Lifestyle Intervention in Independent Living Aged Care (LIILAC) Study (ACTRN12614001133628) involved 102 participants, aged 60-90 y, who were randomly assigned to 1 of 4 intervention groups. Change in overall memory performance was assessed as the primary outcome. Additionally, changes in cognitive task performance, as well as mood, wellness, cardiovascular function, and blood biomarkers, were investigated. RESULTS: While there was no significant change in overall memory performance, there was a significant improvement in spatial working memory performance in the combined exercise and diet group, relative to controls. This combined intervention group also showed an overall improvement in their emotional state, as assessed by the Depression Anxiety Stress Scale, as did the exercise-only group. CONCLUSIONS: This research indicates that diet and exercise programs have the potential to improve aspects of cognition and mood in an aging population. However, given the lower than optimal sample size and lack of resources to reinforce the interventions during the trial, further larger randomized controlled trials are required to substantiate whether the introduction of diet and exercise programs into independent-living facilities is a viable method to preserve cognitive health in older people. This trial was registered at www.ANZCTR.org.au ACTRN 12614001133628 (LIILAC Study).

Modelling Modifiable Predictors of Age-Related Cognitive Decline: Exercise, Aortic Stiffness, and the Importance of Physical Fitness.

BACKGROUND: Previous modelling found that fitness and aortic stiffness both independently predicted spatial working memory (SWM) performance in older people. There is also evidence that greater engagement in moderate intensity exercise contributes to better cognitive performance, potentially working through improving fitness and aortic stiffness. OBJECTIVE: To investigate the effect of exercise on the previously established relationships between fitness, aortic stiffness, and SWM, and whether these associations differ between older adults of higher and lower fitness. METHODS: One hundred and two residents of independent living facilities, aged 60-90 (M = 77.5, SD = 6.9) participated in the study. Measures included computerized cognitive assessment, the Six-Minute Walk fitness test, the CHAMPS physical activity questionnaire, and aortic pulse wave analysis. Multiple structural equation models were used to test hypotheses. RESULTS: Overall, exercise levels had a small additional effect in predicting SWM, working exclusively through fitness, although this was only true for those of lower than average fitness. Additionally, it was found that while fitness was the most important factor in predicting SWM in those of lower fitness, aortic stiffness was the strongest predictor in those of higher fitness. CONCLUSION: Fitness and aortic stiffness are strong predictors of cognition in older people, and greater engagement in exercise predicted better cognition in those who were of lower fitness. Fitter older people may benefit more from interventions which target aortic stiffness in order to preserve cognitive performance as they age, while those who are less fit may benefit most from improving fitness first, including through increased physical activity.

Panax ginseng has no effect on indices of glucose regulation following acute or chronic ingestion in healthy volunteers.

In the absence of effective pharmacotherapy for diabetes there has been an increase in the use of, and research into, alternative treatment strategies. These include exercise, dietary interventions and the use of supplements including extracts of ginseng. Two separate, placebo-controlled, double-blind, cross-over studies investigating the effects of chronic ingestion of Panax ginseng (study 1 used G115, study 2 used Cheong Kwan Jang) on glycated Hb (HbA1c; study 1, n 18; study 2, n 11), fasting plasma insulin (study 1, n 17; study 2, n 12), fasting plasma glucose and postprandial response (following breakfast) (study 1, n 23; study 2, n 14) in healthy volunteers are reported. In both studies it was found that Panax ginseng had no effect on any gluco-regulatory parameter investigated. These results are not consistent with those reported for a diabetic sample (albeit using slightly different outcomes). These results would suggest that chronic use of Panax ginseng by non-diabetic individuals will have little long-term effect on glucose regulation. The benefits to glucose regulation associated with long-term ginseng use may only be present in populations with compromised glucose control; however, further research is needed to confirm such a speculation.

Cognitive and mood effects of 8 weeks' supplementation with 400 mg or 1000 mg of the omega-3 essential fatty acid docosahexaenoic acid (DHA) in healthy children aged 10-12 years.

INTRODUCTION: Despite media and public expectation of efficacy, no study to date has investigated the cognitive and mood effects of omega 3 supplementation in healthy children. SUBJECTS AND METHODS: This randomised, double-blind, placebo-controlled, parallel groups pilot study assessed the cognitive and mood effects of either 400 mg or 1000 mg of docosahexaenoic acid (DHA) in 90 healthy children aged 10-12 years. Cognitive performance and mood was assessed prior to, and 8 weeks following, commencement of treatment. RESULTS: There was a significant treatment effect on one cognitive measure (speed of word recognition), with the lower dose speeding, and the higher dose slowing, performance. Overall, the pattern of results strongly suggests that this effect was due to chance fluctuations in performance and that the treatments had no consistent or interpretable effect on performance. CONCLUSIONS: The results here do not suggest that supplementation with these doses of DHA for 8 weeks has any beneficial effect on brain function in cognitively intact children.