Flavonoid-Rich Mixed Berries Maintain and Improve Cognitive Function Over a 6h Period in Young Healthy Adults

Research with young adults has previously indicated flavonoid-rich berry interventions facilitate improved executive function (EF) and positive affect 20 min–2 h post-dosing. There has been little consideration of the impact of a berry intervention over a working day and interventions have also tended to consider only a single berry type. This study investigated the temporal profile of EF and mood changes over a 6 h period following a mixed-berry intervention. We hypothesized berry-related benefits would be most evident when participants were cognitively compromised on demanding elements of the task or during periods of fatigue. The study employed a single-blind, randomized, placebo controlled, between-subjects design. Forty participants aged 20–30 years consumed a 400 mL smoothie containing equal blueberry, strawberry, raspberry, and blackberry (n = 20) or matched placebo (n = 20). Mood was assessed using the Positive and Negative Affect Schedule; EF was tested using the Modified Attention Network (MANT) and Task Switching (TST) Tasks. Testing commenced at baseline then 2, 4 and 6 h post-dosing. As expected, following placebo intervention, performance decreased across the day as participants became cognitively fatigued. However, following berry intervention, participants maintained accuracy on both cognitive tasks up to and including 6 h, and demonstrated quicker response times on the MANT at 2 and 4 h, and TST at 6 h. This study demonstrates the efficacy of flavonoid rich berries in maintaining or improving cognitive performance across the 6 h day

A study of glycaemic effects following acute anthocyanin-rich blueberry supplementation in healthy young adults

The postprandial response to ingested carbohydrate is recognised as a marker of metabolic health. Postprandial hyperglycaemia is observed in type 2 diabetes mellitus and is a significant risk factor for cardiovascular disease. Cognitive deficits are also associated with type 2 diabetes. Therefore interventions which moderate postprandial glucose profiles are desirable. Here we investigated the impact of anthocyanin-rich wild blueberries on postprandial glucose response. Seventeen healthy young adults consumed a range of doses of freeze-dried wild blueberry powder, in smoothie form, in both sugar-matched and no-added-sugar conditions. Plasma glucose was determined by a capillary sampling method at baseline and at regular intervals up to 2.5 hours postprandially. Blueberries were observed to significantly extend the postprandial glucose response beyond the period observed for a sugar-matched control, characteristic of a beneficial glycaemic response. Furthermore, blueberries were observed to reduce peak postprandial glucose levels, although statistical significance was not achieved. The findings suggest a tempering of the postprandial glucose response in the presence of anthocyanin-rich blueberry, and are discussed with reference to likely glucoregulatory mechanisms of action and their implications for cognitive and type 2 diabetes research

Variable trajectory: a systematic review, analytic synthesis and construct domain consolidation of international measures of competence in doctors and medical students

ABSTRACT Background Competence is assessed throughout a doctor’s career. Failure to identify and manage impaired competence can have critical consequences. Consistent conceptualisation and accurate measurement of this construct is imperative. Therefore, the objective of this review was to identify and evaluate measures used to assess competence in doctors and medical students. Methods A systematic search of the published literature was undertaken between December 2019 and February 2020 for articles reporting on the measurement of competence in doctors and/or medical students. Searches were conducted in the PsychSOURCE, US National Library of Medicine National Institutes of Health, MEDLINE (PubMed), The Cochrane Central Register of Controlled Trials (CENTRAL), and Web of Science electronic databases. Citation screening and forward citation tracking of included studies was carried out to identify any further relevant papers for inclusion. One thousand one-hundred and thirty-six potentially relevant articles were screened. An analytic synthesis approach was implemented to the identification, organization and interpretation of homogenous study and measure characteristics. Results Twelve competence domains were identified from the 153 identified measures. Knowledge and Procedural competence domains were the dominant focus of publications reporting current medical practice, but less so in research-based studies which more frequently assessed interpersonal, psychological, physiological and ethical competencies. In the 105 included articles, the reporting of measurement instrument quality was varied, with comprehensive reporting only present in 53.6% of measures; validation for some of the measures was particularly limited. Discussion Whilst this review included a considerable number of publications reporting the measurement of competence in doctors and medical students, the heterogeneity of the measures and variation of findings limit the ability to evaluate their validity and generalisability. However, this review presents a resource for researchers and medical educators which may inform operational practice and future research. Keywords: Competence · Doctor · Medical student · Physician · Performanc

The effects of acute wild blueberry supplementation on the cognition of 7-10 year old schoolchildren

Purpose: Previous evidence suggests consumption of flavonoids, a sub-class of polyphenols, is associated with improved cognitive function across the lifespan. In particular, acute intervention of a flavonoid-rich wild blueberry (WBB) drink has been shown to boost executive function (EF), short-term memory and mood 2-6 h post-consumption in 7-10 yr old children. However, confirmation of the aspects of EF and memory susceptible to WBB ingestion is required, particularly during childhood, a critical period of neurological development. In addition, the child literature on berry-flavonoid supplementation and cognition highlights the potential for such interventions to elicit positive benefits to real world educational scenarios, such as reading; a complex ability which relies upon aspects of cognition already known to improve following WBB. Methods: Here we examined which aspects of EF and memory are susceptible to acute WBB, as well as investigating whether acute WBB could further benefit reading ability. Fifty-four healthy children, aged 7-10 yrs, consumed a 200ml WBB drink (253mg anthocyanins) or a matched placebo according to a randomised, single-blind, parallel groups design. Verbal memory (Auditory Verbal Learning Task; AVLT), EF (Modified Attention Network Task; MANT), and reading efficiency (Test of Word Reading Efficiency-2; TOWRE-2) were assessed at baseline and 2 h post consumption. Results: For the MANT, significantly quicker RTs were observed for WBB participants when compared to placebo participants on 120 ms trials, without cost to accuracy. Furthermore, WBB participants showed enhanced verbal memory performance on the AVLT, recalling more words than placebo participants on short delay and memory acquisition measures post-consumption. Despite these significant improvements in cognitive performance, no significant effects were observed for reading measures. Conclusion: Consumption of WBB was found to significantly improve memory and attentional aspects of EF. This indicates that a flavonoid-rich blueberry product, equivalent to 240 g or 1½ cups of fresh blueberries can provide acute cognitive benefits in children. These findings support accumulating evidence that flavonoid-rich products are beneficial for healthy brain function, particularly during critical developmental periods. However, the lack of findings relating to reading ability suggested acute WBB may not be sufficient to elicit benefits to reading. Chronic supplementation and other more sensitive reading measures should be considered for examining the effects of WBB on such a complex skill in the future

Dietary flavonoids and human cognition: a meta‐analysis

Abstract: Improving cognition is important in all age groups, from performance in school examinations to prevention of cognitive decline in later life. Dietary polyphenols, in particular flavonoids, have been examined for their benefits to cognitive outcomes. This meta‐analysis evaluates the effects of dietary flavonoids on cognition across the lifespan. In January 2020 databases were searched for randomized controlled trials investigating flavonoid effects on human cognition. Eighty studies, comprising 5519 participants, were included in the final meta‐analysis. The global analysis indicates dietary flavonoids induced significant benefit to cognitive performance (g = 0.148, p < 0.001), with subgroup analyses revealing that cocoa (g = 0.224, p = 0.036), ginkgo (g = 0.187, p ≤ 0.001), and berries (g = 0.149, p = 0.009) yielded the most notable improvements. Significant benefits were observed from chronic studies, in middle‐aged and older adults, and with low and medium doses. The domains of long‐term memory, processing speed, and mood showed sensitivity to flavonoid intervention. This meta‐analysis provides evidence for the positive effects of flavonoids on cognition and highlights several moderating factors. Flavonoid‐based dietary interventions therefore potentially offer a highly accessible, safe, and cost‐effective treatment to help tackle the burden of cognitive decline

The cognitive effects of an acute wild blueberry intervention on 7- to 10-year-olds using extended memory and executive function task batteries

Evidence for the health benefits of blueberries is well documented. In particular memory and executive function benefits have both been found for children aged 7 – 10 in the 6 hour period following acute blueberry consumption. Previous research has utilised a limited number of tasks when considering these domains. Therefore, in two separate experiments, we employed extended memory and executive function task batteries to further understand the extent of blueberry benefits. Following blueberry intervention, children aged 7 – 10 were tested on a memory battery at 75 minutes and an executive function battery at 3 hours. Shorter memory reaction times were observed on the visuo-spatial grid task and shorter executive function reaction times were observed on the congruent trials of the attention network task. Whilst providing further evidence for the cognitive benefits of blueberry consumption in school age children, these findings contrast with previous research where improved accuracy and reaction time benefits have most commonly been found on more cognitively demanding trials. Further research targeted to consider the areas of the brain related to each cognitive domain and how they coincide with mechanisms of action, such as increases in cerebral blood flow following blueberry intervention, is therefore recommended

Can air purification improve sleep quality? A 2-week randomised controlled crossover pilot study in healthy adults

Insufficient quantity and quality of sleep is a public health concern which can be addressed by interventions for improving sleep outcomes. Environmental factors such as poor air quality are a potential target for intervention, particularly in light of associations between air pollution and worse sleep. The aim of this pilot study was to investigate the effects of using an air purifier on sleep outcomes and mood in 30 healthy adults. There were two conditions (i) air purifier with a High Efficiency Particulate Air (HEPA) filter (ii) air purifier with a placebo filter. Participants undertook both conditions, each over two weeks with a two-week washout, following a counterbalanced, double-blind design. Daily sleep outcomes were measured with actigraphy watches and sleep diaries, whilst daily mood was assessed with the Positive and Negative Affect Schedule. The Insomnia Severity Index, the Pittsburgh Sleep Quality Index, and symptoms of anxiety and depression were measured pre and post. The purifier filter was associated with increased total sleep time for an average of 12 minutes per night and increased total time in bed for an average of 19 minutes per night relative to the placebo. There were several sleep and mood outcomes for which no changes were observed, and time awake after sleep onset was higher for the purifier filter. Air quality was better during the HEPA filter condition. These findings offer positive indications that environmental interventions which improve air quality can have benefits for sleep outcomes in healthy populations who are not exhibiting clinical sleep disturbances

Concord grape Juice, cognitive function and driving performance: a 12 week, placebo controlled, randomised, crossover trial in mothers of pre-teen children

Background: Daily consumption of Concord grape juice (CGJ) over three to four months has been shown to improve memory function in adults with mild cognitive impairment, and reduce blood pressure in hypertensive adults. These benefits are likely due to the high concentration of polyphenols in CGJ. Increased stress can impair cognitive function and elevate blood pressure. Thus we examined the potential beneficial effect of CGJ in individuals experiencing somewhat stressful demanding lifestyles. Objective: To examine the effects of twelve weeks’ daily consumption of CGJ on cognitive function, driving performance, and blood pressure in healthy, middle-aged working mothers. Design: Twenty five healthy mothers of pre-teen children, aged 40-50 years, who were employed for > 30 hours/week consumed 12oz (355ml) CGJ (containing 777mg total polyphenols) or an energy, taste and appearance matched placebo daily for twelve weeks according to a randomised, crossover design with a four week washout. Verbal and spatial memory, executive function, attention, blood pressure and mood were assessed at baseline, six weeks and twelve weeks. Immediately following the cognitive battery, a subsample of seventeen females completed a driving performance assessment in the University of Leeds Driving Simulator. The twenty five minute driving task required participants to match the speed and direction of a lead vehicle. Results: Significant improvements in immediate spatial memory and driving performance were observed following CGJ relative to placebo. There was evidence of an enduring effect of CGJ such that participants who received CGJ in arm 1 maintained better performance in the placebo arm. Conclusions: Cognitive benefits associated with chronic consumption of flavonoid-rich grape juice are not exclusive to adults with mild cognitive impairment. Moreover, these cognitive benefits are apparent in complex everyday tasks such as driving. Effects may persist beyond cessation of flavonoid consumption and future studies should carefully consider the length of washout within crossover designs

Can Public Health Interventions Change Immediate and Long-Term Dietary Behaviours? Encouraging Evidence from a Pilot Study of the U.K. Change4Life Sugar Swaps Campaign

The aim of this pilot study was to evaluate the effectiveness of the U.K. Change4Life Sugar Swaps campaign for improving nutritional intake in a small sample of families prior to the 2015 nationwide launch. A total of 49 participants from 14 families received information and materials during a two-week intervention period in November 2014 encouraging them to swap high sugar foods and drinks for low sugar alternatives. Daily dietary intake was reported with online food diaries over four stages, each two weeks in length: (i) baseline (no information provided), (ii) intervention when Sugar Swaps materials were accessible, (iii) immediate follow-up, and (iv) one year on from baseline. Data were analysed for sugar, glucose, fructose, sucrose, lactose, fat, saturated fat, carbohydrate, protein, salt, fibre, vitamin C, and energy. During the intervention, significant daily reductions of 32 g sugar, 11 g fat, and 236 kcal for each family member were observed, among others, and 61% of benefits achieved during the intervention period were maintained at immediate follow-up. Encouragingly, for children, reductions in sugar, sucrose, fat, saturated fat, carbohydrate, and energy were observed one year on. The Sugar Swaps Campaign is potentially an effective public health intervention for improving short- and long-term dietary behaviour for the whole family

Grape seed polyphenol extract and cognitive function in healthy young adults: A randomised, placebo-controlled, parallel-groups acute-on-chronic trial

Grapes are polyphenol-rich, and grape juice intake has shown cognitive benefits in middle-aged females and older adults with mild cognitive impairment. Extracts obtained from grape seeds have similarly been associated with cognitive benefits in older adults. The aim of this research was to investigate whether a highly purified grape seed-derived polyphenol extract was associated with cognitive benefits in healthy young adults following a single acute dose, and chronically following repeated daily dosage over 12 weeks. Following an acute-on-chronic, parallel groups, randomised, double-blind, placebo-controlled design, sixty adults aged 18–30 consumed either a 400 mg grape seed polyphenol extract (GSPE, n = 30) or a placebo (n = 30). Cognitive function was assessed acutely at baseline and 2, 4 and 6 h post consumption, and chronically at 6 and 12 twelve weeks with a computerised battery of multiple cognitive tests. Mood was assessed with the Positive and Negative Affect Schedule. Linear marginal model analysis with baseline included as a covariate did not reveal a consistent pattern of cognitive benefits following the GSPE relative to the placebo either acutely or chronically when considering all outcome measures. GSPE was associated with some improvements in reaction time (acutely) and psychomotor skill (chronically), however the placebo was also associated with some benefits to reaction time and memory. Therefore, a 400 mg GSPE did not consistently improve cognitive function in healthy young adults. These findings suggest that younger, healthy populations are perhaps less sensitive to polyphenol extract doses <400mg relative to older, or cognitively compromised populations