Defining a Continuous Glucose Baseline to assess the impact of nutritional interventions.

Accurate and robust estimation of individuals' basal glucose level is a crucial measure in nutrition research but is typically estimated from one or more morning fasting samples. The use of Continuous Glucose Monitoring (CGM) devices presents an opportunity to define more robust basal glucose levels, which estimates can be generalized to any time of the day. However, to date, no standardized method has been delineated. The current paper seeks to define a reliable algorithm to characterize the individual's basal glucose level over 24 h from CGM measurements. Data drawn from four nutritional intervention studies performed on adults free from chronic diseases were used to define that basal glucose levels were optimally estimated using the 40th percentile of the previous 24 h CGM data. This simple algorithm provides a Continuous Glucose Baseline over 24 h (24 h-CGB) that is an unbiased and highly correlated estimator (r = 0.86, p-value < 0.01) of standard fasting glucose. We conclude that 24-CGB can provide reliable basal glucose estimates across the day while being more robust to interference than standard fasting glucose, adaptable to evolving daily routines and providing useful reference values for free-living nutritional intervention research in non-diabetic individuals.

The interrelationship between sleep, diet, and glucose metabolism.

Obesity and type 2 diabetes (T2D) are increasingly common worldwide. While these disorders have increased in prevalence over the past several decades, there has been a concomitant reduction in sleep duration. Short sleep duration has been associated with higher rates of obesity and T2D, and the causality of these associations and their directionality, continue to necessitate evaluation. In this review we consider the evidence that sleep is an intrinsic factor in the development of obesity and chronic metabolic disorders, such as insulin resistance and T2D, while evaluating a potential bi-directional association. We consider the evidence that diet and meal composition, which are known to impact glycemic control, may have both chronic and acute impact upon sleep. Moreover, we consider that postprandial nocturnal metabolism and peripheral glycemia may affect sleep quality. We propose putative mechanisms whereby acute effects of nighttime glucose excursions may lead to increased sleep fragmentation. We conclude that dietary manipulations, particularly with respect to carbohydrate quality, may confer sleep benefits. Future research may seek to evaluate the effectiveness of synergistic nutrient strategies to promote sleep quality, with particular attention to carbohydrate quality, quantity, and availability as well as carbohydrate to protein ratio.

The association between COVID-19 related food insecurity and weight promoting eating behaviours: The mediating role of distress and eating to cope.

Food insecurity (a lack of stable access to nutritious food) is reliably associated with higher BMI, although the underlying mechanisms are unclear. Past research indicates that this relationship may, in part, be explained by the distress of being food insecure and using food as a coping mechanism. While previous work has focused on long-term food insecurity, the first COVID-19 national lockdown presented a unique opportunity to establish if the same relationships existed for individuals experiencing pandemic related food insecurity. Adults in the United Kingdom (N = 211) were recruited three months after the first UK lockdown via social media. They completed questionnaires on COVID-19 related food insecurity, physical stress, psychological distress, eating to cope, drinking to cope, diet quality, and changes in weight promoting eating behaviours (e.g. consuming larger portions, increased snacking) since the start of the lockdown. A structural equation model revealed that food insecurity was indirectly associated with changes in weight promoting eating behaviours. As predicted, the more instances of pandemic related food insecurity, the more distress individuals reported. Distress was then associated with eating as a way of coping, which in turn was associated with increases in weight promoting eating behaviours. Food insecurity was also indirectly associated with diet quality, but this was via distress only. These results reflect similar pathways observed in individuals reporting chronic food insecurity and strengthens the evidence that distress and eating to cope are generic mediators of food insecurity and eating behaviour.

The Relationship between Pain Sensitivity, Pain Catastrophizing and Hangover Severity.

Recent research found a significant and positive correlation between hangover severity and pain catastrophizing. The current study aimed to verify these findings. Data from N = 673 subjects with a mean (SD) age of 42.2 (19.1) years old (range: 18 to 87 years old) was evaluated. An online survey collected data on alcohol consumption and hangovers related to their heaviest drinking occasion between 15 January and 14 March 2020. When correcting for the amount of alcohol consumed, significant correlations were found between hangover severity and both sensitivity to pain (r = 0.085, p = 0.029) and pain catastrophizing (r = 0.095, p = 0.015). In addition, subjective intoxication correlated significantly with sensitivity to pain (r = 0.080, p = 0.041) and pain catastrophizing (r = 0.099, p = 0.011). Overall, the results were more pronounced in men than women, and the associations with pain catastrophizing were strongest for the subscale assessing rumination. In conclusion, although statistically significant, the observed correlations were of small magnitude. Nevertheless, the observations confirm previous findings that suggest a link between pain perception, alcohol consumption, and hangover severity, which warrants further investigation.

Sensitivity to Experiencing Alcohol Hangovers: Reconsideration of the 0.11% Blood Alcohol Concentration (BAC) Threshold for Having a Hangover.

The 2010 Alcohol Hangover Research Group consensus paper defined a cutoff blood alcohol concentration (BAC) of 0.11% as a toxicological threshold indicating that sufficient alcohol had been consumed to develop a hangover. The cutoff was based on previous research and applied mostly in studies comprising student samples. Previously, we showed that sensitivity to hangovers depends on (estimated) BAC during acute intoxication, with a greater percentage of drinkers reporting hangovers at higher BAC levels. However, a substantial number of participants also reported hangovers at comparatively lower BAC levels. This calls the suitability of the 0.11% threshold into question. Recent research has shown that subjective intoxication, i.e., the level of severity of reported drunkenness, and not BAC, is the most important determinant of hangover severity. Non-student samples often have a much lower alcohol intake compared to student samples, and overall BACs often remain below 0.11%. Despite these lower BACs, many non-student participants report having a hangover, especially when their subjective intoxication levels are high. This may be the case when alcohol consumption on the drinking occasion that results in a hangover significantly exceeds their "normal" drinking level, irrespective of whether they meet the 0.11% threshold in any of these conditions. Whereas consumers may have relative tolerance to the adverse effects at their "regular" drinking level, considerably higher alcohol intake-irrespective of the absolute amount-may consequentially result in a next-day hangover. Taken together, these findings suggest that the 0.11% threshold value as a criterion for having a hangover should be abandoned.

Pain Catastrophising Predicts Alcohol Hangover Severity and Symptoms.

Alcohol hangover is a cause of considerable social and economic burden. Identification of predictors of alcohol hangover severity have the potential to contribute to reductions in costs associated with both absenteeism/presenteeism and health care. Pain catastrophising (PC) is the tendency to ruminate and describe a pain experience in more exaggerated terms. The current study examines the possibility that this cognitive coping strategy may influence experience of alcohol hangover. The aims of the current study were to (1) examine the relationship between hangover severity and PC, (2) explore and identify discreet factors within the Acute Hangover Scale (AHS) and (3) explore whether independent factors/dimensions of acute hangover are differentially predicted by PC. A retrospective survey (n = 86) was conducted in which participants completed the Acute Hangover Scale (AHS); the Pain Catastrophising Scale (PCS); a questionnaire pertaining to the amount of alcohol consumed; and a demographic information questionnaire. Regression analyses showed a significant relationship between PC and hangover severity scores and demonstrated that PC was, in fact, a stronger predictor of perceived hangover severity than estimated peak blood alcohol concentrations (eBACs). Factor analysis of the AHS scale, resulted in the identification of two distinct symptom dimensions; 'Headache and thirst', and 'Gastric and cardiovascular' symptoms. Regression analyses showed that both eBAC and PCS score were significantly associated with 'Headache and thirst'. However, only PCS score was associated with 'Gastric and cardiovascular' symptoms. These novel findings implicate a role for cognitive coping strategies in self-reports of alcohol hangover severity, and may have implications for understanding behavioural response to hangover, as well as suggesting that hangover and PC may be important factors mediating the motivation to drink and/or abuse alcohol, with potential implications in addiction research. Furthermore, these findings suggest that distinct alcohol hangover symptoms may be associated with different mechanisms underlying the experience of alcohol hangover.

Correction to: A randomised controlled trial of a mitochondrial therapeutic target for bipolar depression: mitochondrial agents, N-acetylcysteine, and placebo.

The original article [1] contained two minor errors.

A randomised controlled trial of a mitochondrial therapeutic target for bipolar depression: mitochondrial agents, N-acetylcysteine, and placebo.

BACKGROUND: A phasic dysregulation of mitochondrial bioenergetics may operate in bipolar disorder, increased in mania and decreased in depression. We aimed to examine efficacy of two add-on treatments in bipolar depression: N-acetylcysteine (NAC) and NAC with a combination of nutraceutical agents that may increase mitochondrial biogenesis. METHODS: A three-arm 16-week, double-blind, randomised, placebo-controlled trial, adjunctive to usual treatment, was conducted. Participants (n = 181) with bipolar disorder and current depressive symptoms were randomised to 2000 mg/day NAC (n = 59), 2000 mg/day NAC with the combination nutraceutical treatment (CT, n = 61), or placebo (n = 61). The primary outcome was change in Montgomery-Åsberg Depression Rating Scale (MADRS) total score from baseline to week 16. Young Mania Rating Scale, Clinical Global Impression (CGI)-Improvement and CGI-Severity scales, Patient Global Impression scale, Social and Occupational Functioning Assessment Scale (SOFAS), Longitudinal Interval Follow-Up Evaluation - Range of Impaired Functioning Tool (LIFE-RIFT), and Quality of Life Enjoyment, and Satisfaction Questionnaire Short Form (Q-LES-Q-SF) were secondary outcomes. RESULTS: One hundred forty-eight participants had post-randomisation data and were analysed (NAC = 52, CT = 47, Placebo = 49). No between-group differences were found for the rate of change between baseline and 16 weeks on any of the clinical and functioning variables. Improvements in MADRS, BDRS, SOFAS, and LIFE-RIFT scores from baseline to the week 20 post-discontinuation visit were significantly greater in the CT group compared to those in the placebo. At week 20, the CGI-I was significantly lower in the CT group versus placebo. Gastrointestinal symptoms were significantly greater in the NAC than in the placebo group. CONCLUSIONS: These overall negative results, with no significant differences between groups detected at the primary outcome but some positive secondary signals, suggest either delayed benefit of the combination or an improvement of symptoms on withdrawal which warrants further exploration regarding the composition, mechanisms, and application of mitochondrial agents in illnesses characterised by mitochondrial dysfunction. TRIAL REGISTRATION: ANZCTR ( ACTRN12612000830897 ).

The role of diet and nutrition on mental health and wellbeing.

Mental, neurological and substance-use disorders presently represent the greatest global burden of disease. Likewise, depression and other psychopathologies are elevated risk comorbidities of other health hazards, such as obesity. Nutrition has been implicated in behaviour, mood and in the pathology and treatment of mental illness. In this brief editorial, we aim to set the scale of the problem in context and overview advances and recent evidence linking nutrition to psychological outcomes. The purpose of the 2016 Nutrition Society Winter Meeting, 'Diet, nutrition and mental health and wellbeing' was to review where the evidence is strong, where there are unmet needs for research and to draw together the communities working in this area to share their findings. The papers presented demonstrated clear advancements that are being made in this field. The meeting illustrated compelling support for nutrition as a modifiable risk factor. The present research in the field and evidence presented at the 2016 Nutrition Society Winter Meeting lead us to postulate that even interventions with relatively modest effect sizes may plausibly and significantly curtail the disease burden of mental and neurological disease by food- and nutrient-based approaches.

The impact of diet-based glycaemic response and glucose regulation on cognition: evidence across the lifespan.

The brain has a high metabolic rate and its metabolism is almost entirely restricted to oxidative utilisation of glucose. These factors emphasise the extreme dependence of neural tissue on a stable and adequate supply of glucose. Whereas initially it was thought that only glucose deprivation (i.e. under hypoglycaemic conditions) can affect brain function, it has become apparent that low-level fluctuations in central availability can affect neural and consequently, cognitive performance. In the present paper the impact of diet-based glycaemic response and glucose regulation on cognitive processes across the lifespan will be reviewed. The data suggest that although an acute rise in blood glucose levels has some short-term improvements of cognitive function, a more stable blood glucose profile, which avoids greater peaks and troughs in circulating glucose is associated with better cognitive function and a lower risk of cognitive impairments in the longer term. Therefore, a habitual diet that secures optimal glucose delivery to the brain in the fed and fasting states should be most advantageous for the maintenance of cognitive function. Although the evidence to date is promising, it is insufficient to allow firm and evidence-based nutritional recommendations. The rise in obesity, diabetes and metabolic syndrome in recent years highlights the need for targeted dietary and lifestyle strategies to promote healthy lifestyle and brain function across the lifespan and for future generations. Consequently, there is an urgent need for hypothesis-driven, randomised controlled trials that evaluate the role of different glycaemic manipulations on cognition.

Does familial risk for alcohol use disorder predict alcohol hangover?

AIMS: Positive family history of alcohol use disorder (FHP), a variable associated with propensity for alcohol use disorder (AUD), has been linked with elevated hangover frequency and severity, after controlling for alcohol use. This implies that hangover experiences may be related to AUD. However, inadequate control of alcohol consumption levels, low alcohol dose and testing for hangover during the intoxication phase detract from these findings. Here, we present further data pertinent to understanding the relationship between family history and alcohol hangover. METHODS: Study 1 compared past year hangover frequency in a survey of 24 FHP and 118 family history negative (FHN) individuals. Study 2 applied a quasi-experimental naturalistic approach assessing concurrent hangover severity in 17 FHP and 32 FHN individuals the morning after drinking alcohol. Both studies applied statistical control for alcohol consumption levels. RESULTS: In Study 1, both FHP status and estimated blood alcohol concentration on the heaviest drinking evening of the past month predicted the frequency of hangover symptoms experienced over the previous 12 months. In Study 2, estimated blood alcohol concentration the previous evening predicted hangover severity but FHP status did not. CONCLUSIONS: FHP, indicating familial risk for AUD, was not associated with concurrent hangover severity but was associated with increased estimates of hangover frequency the previous year.

Systematic literature review shows that appetite rating does not predict energy intake.

Ratings of appetite are commonly used to assess appetite modification following an intervention. Subjectively rated appetite is a widely employed proxy measure for energy intake (EI), measurement of which requires greater time and resources. However, the validity of appetite as a reliable predictor of EI has not yet been reviewed systematically. This literature search identified studies that quantified both appetite ratings and EI. Outcomes were predefined as: (1) agreement between self-reported appetite scores and EI; (2) no agreement between self-reported appetitescores and EI. The presence of direct statistical comparison between the endpoints, intervention type and study population were also recorded. 462 papers were included in this review. Appetite scores failed to correspond with EI in 51.3% of the total studies. Only 6% of all studies evaluated here reported a direct statistical comparison between appetite scores and EI. χ2 analysis demonstrated that any relationship between EI and appetite was independent of study type stratification by age, gender or sample size. The very substantive corpus reviewed allows us to conclude that self-reported appetite ratings of appetite do not reliably predict EI. Caution should be exercised when drawing conclusions based from self-reported appetite scores in relation to prospective EI.

The effect of alcohol hangover on choice response time.

The effect of alcohol hangover on cognitive processing has received little attention. We explored the effect of alcohol hangover on choice response time (RT), a dominant dependent variable (DV) in cognitive research. Prior research of the effect of hangover on RT has produced mixed findings; all studies reviewed relied exclusively on estimates of central tendency (e.g. mean RT), which has limited information value. Here we present novel analytical methods by going beyond mean RT analysis. Specifically, we examined performance in hangover conditions (n=31) across the whole RT distribution by fitting ex-Gaussian models to participant data, providing a formal description of the RT distribution. This analysis showed detriments to performance under hangover conditions at the slower end of the RT distribution and increased RT variance under hangover conditions. We also fitted an explicit mathematical process model of choice RT - the diffusion model - which estimates parameters reflecting psychologically-meaningful processes underlying choice RT. This analysis showed that hangover reduced information processing efficiency during response selection, and increased response caution; changes in these parameters reflect hangover affecting core decisional-components of RT performance. The implications of the data as well as the methods used for hangover research are discussed.

Improved working memory performance following administration of a single dose of American ginseng (Panax quinquefolius L.) to healthy middle-age adults.

OBJECTIVE: A ginsenoside-rich extract of American ginseng (Panax quinquefolius L.), Cereboost(TM), was previously shown to improve working memory and mood in healthy young individuals. The present study represented a partial replication investigating whether these effects extended to healthy middle-aged individuals. METHODS: Fifty-two healthy volunteers (40-60 years old, mean age 51.63) received 200 mg of P. quinquefolius or a matching placebo according to a double-blind, placebo-controlled, balanced, crossover design. The Cognitive Drug Research battery and the Computerised Mental Performance Assessment System were used to evaluate cognitive performance at baseline then 1, 3 and 6 h following treatment. Blood glucose and mood were co-monitored. RESULTS: Compared with placebo, P. quinquefolius improved cognitive performance on 'Working Memory' factor at 3 h. Similar effects were observed in one of the two tasks making up this factor, spatial working memory. There were no significant effects on mood or blood glucose levels. CONCLUSIONS: These data confirm that P. quinquefolius can acutely benefit working memory and extend the age range of this effect to middle-aged individuals. These changes are unlikely to be underpinned by modulation of blood glucose in this population.

Dysbiosis of the gut microbiota in disease.

There is growing evidence that dysbiosis of the gut microbiota is associated with the pathogenesis of both intestinal and extra-intestinal disorders. Intestinal disorders include inflammatory bowel disease, irritable bowel syndrome (IBS), and coeliac disease, while extra-intestinal disorders include allergy, asthma, metabolic syndrome, cardiovascular disease, and obesity.

Effects of two doses of glucose and a caffeine-glucose combination on cognitive performance and mood during multi-tasking.

BACKGROUND: This study assessed the effects of two doses of glucose and a caffeine-glucose combination on mood and performance of an ecologically valid, computerised multi-tasking platform. MATERIALS AND METHODS: Following a double-blind, placebo-controlled, randomised, parallel-groups design, 150 healthy adults (mean age 34.78 years) consumed drinks containing placebo, 25 g glucose, 60 g glucose or 60 g glucose with 40 mg caffeine. They completed a multi-tasking framework at baseline and then 30 min following drink consumption with mood assessments immediately before and after the multi-tasking framework. Blood glucose and salivary caffeine were co-monitored. RESULTS: The caffeine-glucose group had significantly better total multi-tasking scores than the placebo or 60 g glucose groups and were significantly faster at mental arithmetic tasks than either glucose drink group. There were no significant treatment effects on mood. Caffeine and glucose levels confirmed compliance with overnight abstinence/fasting, respectively, and followed the predicted post-drink patterns. CONCLUSION: These data suggest that co-administration of glucose and caffeine allows greater allocation of attentional resources than placebo or glucose alone. At present, we cannot rule out the possibility that the effects are due to caffeine alone Future studies should aim at disentangling caffeine and glucose effects.

A critical analysis of alcohol hangover research methodology for surveys or studies of effects on cognition.

RATIONALE: Alcohol hangover may be defined as an adverse effect of heavy alcohol consumption present after sufficient time has elapsed for the alcohol to have been eliminated from the blood. Understanding how hangover may impair performance is important for public safety; yet, there is relatively little hangover research. This paper outlines good practice for future studies. OBJECTIVES: This paper presents a critical analysis of hangover methodology for surveys or studies of effects on cognition with human subjects and provides suggestions for optimum research practice for laboratory-based and naturalistic alcohol hangover studies. RESULTS: Four hangover symptom scales have been developed and subjected to psychometric testing. For retrospective assessment, we recommend the Hangover Symptoms Scale (HSS) or the Alcohol Hangover Severity Scale (AHSS). For concurrent assessment of hangover symptoms, we recommend either the Acute Hangover Scale (AHS), the five-item version of the HSS, or the AHSS. In research aiming to assess the cognitive effects of alcohol hangover, we suggest focusing on the cognitive domains of attention, memory and executive function, and we specify a number of tests within these cognitive domains that are likely to be sensitive to any decrements due to hangover. Finally, we argue that naturalistic studies should assess biological markers to improve the accuracy of estimates of alcohol consumption. Specifically, we recommend the assessment of ethyl glucuronide (EtG) for this purpose. CONCLUSIONS: Recommendations are made with respect to assessing hangover symptoms, cognitive effects of hangover and biological markers of alcohol consumption.

Effects of chocolate on cognitive function and mood: a systematic review.

A systematic review was conducted to evaluate whether chocolate or its constituents were capable of influencing cognitive function and/or mood. Studies investigating potentially psychoactive fractions of chocolate were also included. Eight studies (in six articles) met the inclusion criteria for assessment of chocolate or its components on mood, of which five showed either an improvement in mood state or an attenuation of negative mood. Regarding cognitive function, eight studies (in six articles) met the criteria for inclusion, of which three revealed clear evidence of cognitive enhancement (following cocoa flavanols and methylxanthine). Two studies failed to demonstrate behavioral benefits but did identify significant alterations in brain activation patterns. It is unclear whether the effects of chocolate on mood are due to the orosensory characteristics of chocolate or to the pharmacological actions of chocolate constituents. Two studies have reported acute cognitive effects of supplementation with cocoa polyphenols. Further exploration of the effect of chocolate on cognitive facilitation is recommended, along with substantiation of functional brain changes associated with the components of cocoa.

Response variability to glucose facilitation of cognitive enhancement.

Glucose facilitation of cognitive function has been widely reported in previous studies (including our own). However, several studies have also failed to detect glucose facilitation. There is sparsity of research examining the factors that modify the effect of glucose on cognition. The aims of the present study were to (1) demonstrate the previously observed enhancement of cognition through glucose administration and (2) investigate some of the factors that may exert moderating roles on the behavioural response to glucose, including glucose regulation, body composition (BC) and hypothalamic­pituitary­adrenal axis response. A total of twenty-four participants took part in a double-blind, placebo-controlled, randomised, repeated-measures study, which examined the effect of 25 and 60 g glucose compared with placebo on cognitive function. At 1 week before the study commencement, all participants underwent an oral glucose tolerance test. Glucose facilitated performance on tasks of numeric and spatial working memory, verbal declarative memory and speed of recognition. Moderating variables were examined using several indices of glucoregulation and BC. Poorer glucoregulation predicted improved immediate word recall accuracy following the administration of 25 g glucose compared with placebo. Those with better glucoregulation showed performance decrements on word recall accuracy following the administration of 25 g glucose compared with placebo. These findings are in line with accumulating evidence that glucose load may preferentially enhance cognition in those with poorer glucoregulation. Furthermore, the finding that individuals with better glucoregulation may suffer impaired performance following a glucose load is novel and requires further substantiation.

Starting out - Inpatients with dementia showed me how much we need to improve care.

I was on a gastroenterology ward placement during my first year of training when I read a poem by an unknown author with dementia.