Effects on cognitive performance of modulating the postprandial blood glucose profile at breakfast

Association of hyperglycaemia and hyperlipidaemia with cognitive dysfunction in schizophrenia spectrum disorder

The objective of the study was to investigate the association of blood glucose and lipid profile parameters with cognitive impairment in schizophrenia. A total of 200 schizophrenia patients and 169 controls were enrolled in the study. Blood glucose and lipid profile were estimated in all the subjects. Cognition was assessed using Addenbrooke cognitive examination-III (ACE-III). Fasting glucose (p ≤ .001) and triacylglycerol (p = .018) were increased and HDL-Cholesterol (p ≤ .001), was reduced in schizophrenia. Glucose (r = -0.158, p = .026), total cholesterol (r = -0.249, p = .0001) and triacylglycerol (r = -0.168, p = .018) was negatively correlated with total ACE III score. Triacylglycerol (p = .041) was elevated in cases with mild cognitive impairment. Plasma glucose, total cholesterol and triacylglycerol were associated with various cognitive domains suggesting that hyperglycaemia and hyperlipidaemia might increase the risk of cognitive impairment in schizophrenia.

Bioactive Properties of Bread Formulated with Plant-based Functional Ingredients Before Consumption and Possible Links with Health Outcomes After Consumption- A Review

Bread is a commonly consumed staple and could be a viable medium to deliver plant-based ingredients that demonstrate health effects. This review brings together published evidence on the bioactive properties of bread formulated with plant-based ingredients. Health effects associated with the consumption of bread formulated with plant-based functional ingredients was also reviewed. Bioactive properties demonstrated by the functional ingredients fruits and vegetables, legumes, nuts and tea incorporated into bread include increased phenolic and polyphenolic content, increased antioxidant activity, and extension of bread shelf-life by impairment of lipid and protein oxidation. Acute health effects reported included appetite suppression, reduced diastolic blood pressure, improvements in glycaemia, insulinaemia and satiety effect. These metabolic effects are mainly short lived and not enough for a health claim. Longer term studies or comparison of those who consume and those who do not are needed. The incorporation of plant-based functional ingredients in bread could enhance the health-promoting effects of bread.

The impact of glycaemic load on cognitive performance: A meta-analysis and guiding principles for future research

The effect of breakfast glycaemic load (GL) on cognition was systematically examined. Randomised and non-randomised controlled trials were identified using PubMed, Scopus, and Cochrane Library (up to May 2022). 15 studies involving adults (aged 20 - 80 years) were included. Studies had a low risk, or some concerns, of bias. A random-effects meta-analysis model revealed no effect of GL on cognition up to 119 min post-consumption. However, after 120 min, immediate episodic memory scores were better following a low-GL compared to a high-GL (SMD = 0.16, 95% confidence interval [CI] = -0.00 to 0.32, p = 0.05, I2 = 5%). Subgroup analyses indicated that the benefit was greater in younger adults (<35 years) and those with better GT. A qualitative synthesis of 16 studies involving children and adolescents (aged 5 - 17 years) suggested that a low-GL breakfast may also benefit episodic memory and attention after 120 min. Methodological practises were identified which could explain a failure to detect benefits in some studies. Consequently, guiding principles were developed to optimise future study design.

Dietary Fibre and Organic Acids in Kiwifruit Suppress Glycaemic Response Equally by Delaying Absorption-A Randomised Crossover Human Trial with Parallel Analysis of 13C-Acetate Uptake

Non-sugar components of kiwifruit reduce the amplitude of the glycaemic response to co-consumed cereal starch. We determined the relative contribution of different non-sugar kiwifruit components to this anti-glycaemic effect. Healthy participants (n = 9) ingested equal carbohydrate meals containing 20 g starch as wheat biscuit (WB, 30 g), and the sugar equivalent of two kiwifruit (KFsug, 20.4 g), either intrinsic or added as glucose, fructose and sucrose (2:2:1). The meals were WB+KFsug (control, no non-sugar kiwifruit components), WB + whole kiwifruit pulp (WB+KF), WB + neutralised kiwifruit pulp (WB+KFneut), WB + low-fibre kiwifruit juice (WB+KFjuice) and WB+KFsug + kiwifruit organic acids (WB+KFsug+OA). All meals were spiked with 100 mg sodium [1-13C] acetate to measure intestinal absorption. Each participant ingested all meals in random order. Blood glucose and breath 13CO2 were measured at ingestion and at 15 min intervals up to 180 min. Compared with WB+KFsug, whole kiwifruit pulp (WB+KF) almost halved glycaemic response amplitude (p < 0.001), reduced incremental area under the blood glucose response curve (iAUC) at 30 min (peak) by 50% (p < 0.001), and averted late postprandial hypoglycaemia. All other treatments suppressed response amplitude half as much as whole kiwifruit and averted acute hypoglycaemia, with little effect on iAUC. Effects on 13CO2 exhalation paralleled effects on blood glucose (R2 = 0.97). Dietary fibre and organic acids contributed equally to the anti-glycaemic effect of kiwifruit by reducing intestinal absorption rate. Kiwifruit flesh effectively attenuates glycaemic response in carbohydrate exchange, as it contains fructose, dietary fibre and organic acids.

Harpephyllum caffrum fruit (wild plum) facilitates glucose uptake and modulates metabolic activities linked to neurodegeneration in isolated rat brain: An in vitro and in silico approach

Alteration in brain glucose metabolism due to glucose uptake reduction has been described in the onset of certain neurodegenerative disorders. This study determined Harpephyllum caffrum fruit's potential ability to improve glucose uptake and its modulatory effects on intrinsic antioxidant, glucogenic, cholinergic, and nucleotide-hydrolyzing enzyme activities in isolated rat brain. Consequently, the bioactive compounds of the fruits were identified with LC-MS. The fruit significantly improved brain glucose uptake following coincubation with glucose and brain tissue. The fruit extract also elevated GSH level, SOD, catalase, glycogen phosphorylase, and ENTPDase activities while simultaneously suppressing NO and malonaldehyde levels and fructose-1,6-bisphosphatase, ATPase, acetylcholinesterase and butyrylcholinesterase activities. LC-MS analysis revealed S-methylcysteine sulfoxide, dihydroquercetin, 3,4-dimethyl-2,5-bis(3,4,5-trimethoxyphenyl) tetrahydrofuran (MTHF), nobiletin, puerarin, quercetin 3-rutinoside, 8-D-glucosyl-4',5,7-trihydroxyflavone, asperulosidic acid, 1,2,4,6-tetragalloylglucose, and phellamurin. This study suggests the neuroprotective effects of H. caffrum fruit due to its ability to enhance glucose uptake, attenuate glucose-induced oxidative stress while modulating glucogenic, cholinergic, and nucleotide-hydrolyzing enzyme activities in normal brain tissues. PRACTICAL APPLICATIONS: Available scientific evidence describes oxidative stress as one of the physiological processes contributing to aging-associated neurodegeneration in humans. In this regard, commonly consumed natural products from plants have attracted much interest due to their ability to mitigate redox imbalance-related pathologies that affect various organs in the body such as the brain. Harpephyllum caffrum or bush mango is an evergreen plant native to the South African vegetation. The fruit from the plant is consumed locally as food or specifically for improving the nutritional quality of meals as deserts or condiments. While previous findings described the high antioxidant properties of the fruits, this study reported possible mechanisms via which the plant may exhibit ameliorative effects against oxidative stress-related neurological disorders in the brain. Hence, findings from the current work present another justification for the significance of fruits as a safer nutraceutical alternative for therapy in neurological disease management.

Impact of lunch with carbohydrates differing in glycemic index on children's cognitive functioning in the late postprandial phase: a randomized crossover study

Purpose

Studies about effects of lunch dietary Glycemic Index (GI) on cognition of schoolchildren are scarce. Our previous CogniDo GI study found no changes of cognition in the early postprandial phase after consumption of two rice types with medium vs. high dietary GI for lunch (i.e., 45 min after starting lunch). This study investigated whether the dietary GI of lunch has an impact on cognition of schoolchildren in the late postprandial phase, 90 min after lunch.

Methods

A randomized, 2 × 2 crossover intervention study was conducted at a comprehensive school with 5th and 6th grade students. Participants (n = 212) were randomly assigned to either sequence 1 or 2. In the first period, participants of sequence 1 received a dish with high GI rice (GI: 79), those of sequence 2 with medium GI rice (GI: 64)—in the second period, 1 week later, vice versa. Computer-based cognitive testing was performed 90 min after lunch examining tonic alertness, visual search and task switching, and working memory. Treatment effects and treatment effects adjusted for estimated lunch glycemic load (GL) were analyzed using a linear mixed model.

Results

The selected cognitive parameters were not affected by the GI of lunch 90 min after lunch, neither after intention-to-treat nor in the per-protocol analysis. Adjustment for GL also did not change results.

Conclusion

The present study revealed no notable differences after the consumption of two rice types with medium vs. high dietary GI for lunch in children’s cognitive function in the late postprandial phase, 90 min after lunch.

Clinical trial registration

German Clinical Trials Register (DRKS00013597); date of registration: 16/04/2018, retrospectively registered.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00394-021-02766-y.

The impact of dietary macronutrient intake on cognitive function and the brain

Macronutrients - carbohydrates, fats, and proteins - supply the nutrients required for optimal functioning. Inadequate intake compromises both physical and brain health. We synthesized research on macronutrients from whole meals on cognitive function in healthy adults and identified underlying mechanisms. Intake of simple carbohydrates ('sugars') is consistently associated with decreased global cognition whereas consumption of complex carbohydrates correlates with successful brain aging and improved memory both in the short- and long-term. Saturated fatty acid intake correlates with decreased memory and learning scores whereas omega-3 intake correlates positively with memory scores. Protein intake boosts executive function and working memory when task-demands are high. Individual differences affecting the macronutrient-cognition relationship are age, physical activity, and glucose metabolism. Neural correlates reflect findings on cognitive functions: cortical thickness and cerebral amyloid burden correlate with sugar intake, inflammatory status and cerebral glucose metabolism correlate with fatty acid intake. Key mechanisms by which dietary macronutrients affect the brain and cognition include glucose and insulin metabolism, neurotransmitter actions, and cerebral oxidation and inflammation. In conclusion, macronutrient intake affects cognitive function both acutely and in the long-term, involving peripheral and central mechanisms. A healthy diet supports brain integrity and functionality, whereas inadequate nutrition compromises it. Studying diet can be key to nutritional recommendations, thereby improving the landscape of mental health and healthy brain aging.

Plasma brain-derived neurotrophic factor and dynamic cerebral autoregulation in acute response to glycemic control following breakfast in young men

We examined the acute impact of both low- and high-glycemic index (GI) breakfasts on plasma brain-derived neurotrophic factor (BDNF) and dynamic cerebral autoregulation (dCA) compared with breakfast omission. Ten healthy men (age 24 ± 1 yr) performed three trials in a randomized crossover order; omission and Low-GI (GI = 40) and High-GI (GI = 71) breakfast conditions. Middle cerebral artery velocity (transcranial Doppler ultrasonography) and arterial pressure (finger photoplethysmography) were continuously measured for 5 min before and 120 min following breakfast consumption to determine dCA using transfer function analysis. After these measurements of dCA, venous blood samples for the assessment of plasma BDNF were obtained. Moreover, blood glucose was measured before breakfast and every 30 min thereafter. The area under the curve of 2 h postprandial blood glucose in the High-GI trial was higher than the Low-GI trial (P < 0.01). The GI of the breakfast did not affect BDNF. In addition, both very-low (VLF) and low-frequency (LF) transfer function phase or gains were not changed during the omission trial. In contrast, LF gain (High-GI P < 0.05) and normalized gain (Low-GI P < 0.05) were decreased by both GI trials, while a decrease in VLF phase was observed in only the High-GI trial (P < 0.05). These findings indicate that breakfast consumption augmented dCA in the LF range but High-GI breakfast attenuated cerebral blood flow regulation against slow change (i.e., the VLF range) in arterial pressure. Thus we propose that breakfast and glycemic control may be an important strategy to optimize cerebrovascular health.

Mens Sana in Corpore Sano: Does the Glycemic Index Have a Role to Play?

Although diet interventions are mostly related to metabolic disorders, nowadays they are used in a wide variety of pathologies. From diabetes and obesity to cardiovascular diseases, to cancer or neurological disorders and stroke, nutritional recommendations are applied to almost all diseases. Among such disorders, metabolic disturbances and brain function and/or diseases have recently been shown to be linked. Indeed, numerous neurological functions are often associated with perturbations of whole-body energy homeostasis. In this regard, specific diets are used in various neurological conditions, such as epilepsy, stroke, or seizure recovery. In addition, Alzheimer’s disease and Autism Spectrum Disorders are also considered to be putatively improved by diet interventions. Glycemic index diets are a novel developed indicator expected to anticipate the changes in blood glucose induced by specific foods and how they can affect various physiological functions. Several results have provided indications of the efficiency of low-glycemic index diets in weight management and insulin sensitivity, but also cognitive function, epilepsy treatment, stroke, and neurodegenerative diseases. Overall, studies involving the glycemic index can provide new insights into the relationship between energy homeostasis regulation and brain function or related disorders. Therefore, in this review, we will summarize the main evidence on glycemic index involvement in brain mechanisms of energy homeostasis regulation.

Short-term effects of carbohydrates differing in glycemic index (GI) consumed at lunch on children's cognitive function in a randomized crossover study

Background

Intervention studies suggest an influence of breakfast dietary glycemic index (GI) on children’s cognition. The Cognition Intervention Study Dortmund-GI-I study examined whether lunch dietary GI might have short-term effects on selected cognitive parameters.

Methods

A randomized crossover study was performed at a comprehensive school on 2 test days. One hundred and eighty-nine participants (5th and 6th grade) were randomly assigned to one of the two sequences, medium-high GI (m-hGI) or high-medium GI (h-mGI), following block randomization. In the first period, one group received a dish containing hGI rice (GI: 86) ad libitum, the other mGI rice (GI: 62)—1 week later, in the second period, vice versa. Tonic alertness, task switching, and working memory updating were tested with a computerized test battery 45 min after beginning of lunch break. Treatment effects were estimated using the t test for normally distributed data or the Wilcoxon rank-sum test for non-normally distributed data.

Results

The crossover approach revealed no effects of lunch dietary GI on the tested cognitive parameters in the early afternoon. However, we determined carryover effects for two parameters, and therefore analyzed only data of the first period. The reaction time of the two-back task (working memory updating) was faster (p = 0.001) and the count of commission errors in the alertness task was lower (p = 0.04) in the hGI group.

Conclusion

No evidence of short-term effects of lunch dietary GI on cognition of schoolchildren was found. Potential positive effects on single parameters of working memory updating and tonic alertness favoring hGI rice need to be verified.

Glycaemic regulation, appetite and ex vivo oxidative stress in young adults following consumption of high-carbohydrate cereal bars fortified with polyphenol-rich berries

Consumption of certain berries appears to slow postprandial glucose absorption, attributable to polyphenols, which may benefit exercise and cognition, reduce appetite and/or oxidative stress. This randomised, crossover, placebo-controlled study determined whether polyphenol-rich fruits added to carbohydrate-based foods produce a dose-dependent moderation of postprandial glycaemic, glucoregulatory hormone, appetite and ex vivo oxidative stress responses. Twenty participants (eighteen males/two females; 24 (sd 5) years; BMI: 27 (sd 3) kg/m2) consumed one of five cereal bars (approximately 88 % carbohydrate) containing no fruit ingredients (reference), freeze-dried black raspberries (10 or 20 % total weight; LOW-Rasp and HIGH-Rasp, respectively) and cranberry extract (0·5 or 1 % total weight; LOW-Cran and HIGH-Cran), on trials separated by ≥5 d. Postprandial peak/nadir from baseline (Δmax) and incremental postprandial AUC over 60 and 180 min for glucose and other biochemistries were measured to examine the dose-dependent effects. Glucose AUC0-180 min trended towards being higher (43 %) after HIGH-Rasp v. LOW-Rasp (P=0·06), with no glucose differences between the raspberry and reference bars. Relative to reference, HIGH-Rasp resulted in a 17 % lower Δmax insulin, 3 % lower C-peptide (AUC0-60 min and 3 % lower glucose-dependent insulinotropic polypeptide (AUC0-180 min) P&lt;0·05. No treatment effects were observed for the cranberry bars regarding glucose and glucoregulatory hormones, nor were there any treatment effects for either berry type regarding ex vivo oxidation, appetite-mediating hormones or appetite. Fortification with freeze-dried black raspberries (approximately 25 g, containing 1·2 g of polyphenols) seems to slightly improve the glucoregulatory hormone and glycaemic responses to a high-carbohydrate food item in young adults but did not affect appetite or oxidative stress responses at doses or with methods studied herein.

Breakfast Nutritional Quality and Cognitive Interference in University Students from Mexico City

Skipping breakfast might have an impact on cognitive functions, such as interference, which is a basic capacity of executive functions that denotes the possibility of controlling an automated response. This study aimed to analyze the association between nutritional quality of breakfast and cognitive interference in a sample of university students. A cross-sectional study was conducted, a total of 422 students between 18 and 25 years participated. Cognitive interference was assessed with the Stroop Test. Breakfast was assessed with a questionnaire assigning a score for each serving of each food group that was consumed. Logistic regression models were performed. The performance in cognitive tasks was slower in those who had a poor breakfast (32.9 ± 6 vs 29.3 ± 6 s, p < 0.050). Poor cognitive interference was greater in students with poor breakfast (53% versus 23%, p = 0.001). A slower word reading was associated with skipping vegetables (OR: 2.78, 95% CI: 0.09-2.13), and cereals (OR: 1.70, 95% CI: 1.03-2.81). Wrong color identification was associated with skipping fruits (OR: 1.55, 95% CI: 1.43-1.99) and animal protein sources (OR: 1.63, 95% CI: 1.07-2.49). Skipping fat-rich cereals was a protector factor (OR: 0.55, 95% CI: 0.36-0.85). Difficulty in the ability to inhibit interference was associated with skipping vegetables (OR: 2.72, 95% CI: 1.25-4.80) and cereals (OR: 2.65, 95% CI: 1.28-4.68). The nutritional quality of breakfast was associated with the time spent answering the Stroop test, but not with cognitive interference.

Comparative Effect of Low-Glycemic Index versus High-Glycemic Index Breakfasts on Cognitive Function: A Systematic Review and Meta-Analysis

This systematic review and meta-analysis aims to compare the effect of High-Glycemic Index (GI) versus Low-GI breakfasts on cognitive functions, including memory and attention, of children and adolescents. We systematically searched the MEDLINE (via PubMed), EMBASE, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Web of Science databases, from their inception until June 2019. Articles comparing the effect of Low-GI versus High-GI breakfasts on the cognitive function (i.e., immediate memory, delayed memory, and attention) of children and adolescents were included. The DerSimonian and Laird method was used to compute the pooled effect sizes (ESs) and their respective 95% confidence intervals (CIs). The pooled ESs were 0.13 (95% CI: −0.11, 0.37) for immediate memory and 0.07 (95% CI: −0.15, 0.28) for delayed memory. For attention, the pooled ES was −0.01 (95% CI: −0.27, 0.26). In summary, GI breakfasts do not affect cognitive domains in children and adolescents.

Dietary glycaemic index and cognitive function: prospective associations in adults of the 1946 British birth cohort

Objective

Evidence suggests that the rate of glucose release following consumption of carbohydrate-containing foods, defined as the glycaemic index (GI), is inversely associated with cognitive function. To date, most of the evidence stems from either single-meal studies or highly heterogeneous cohort studies. We aimed to study the prospective associations of diet GI at age 53 years with outcomes of verbal memory and letter search tests at age 69 years and rate of decline between 53 and 69 years.

Design

Longitudinal population-based birth cohort study.

Setting

MRC National Survey for Health and Development.

Participants

Cohort members (n 1252).

Results

Using multivariable linear and logistic regression, adjusted for potential confounders, associations of higher-GI diet with lower verbal memory, lower letter search speed and lower number of hits in a letter search test were attenuated after adjustments for cognitive ability at age 15 years, educational attainment, further training and occupational social class. No association was observed between diet GI at 53 years and letter search accuracy or speed–accuracy trade-off at 69 years, or between diet GI at 53 years and rate of decline between 53 and 69 years in any cognitive measure.

Conclusions

Diet GI does not appear to predict cognitive function or decline, which was mainly explained by childhood cognitive ability, education and occupational social class. Our findings confirm the need for further research on the association between diet and cognition from a life-course perspective.

Impact of rye-based evening meals on cognitive functions, mood and cardiometabolic risk factors: a randomized controlled study in healthy middle-aged subjects

Background

Whole grain (WG) intake is associated with reduced risk of obesity, type 2 diabetes and cardiovascular disease, whereas type 2 diabetes increases the risk of cognitive decline and dementia. The purpose of this study was to investigate the effects of short-term intervention with WG rye on cognitive functions, mood and cardiometabolic risk markers in middle-aged test subjects.

Method

Rye-based breads were provided to 38 healthy test subjects (aged 52-70y) during three consecutive days in a crossover study design, using white wheat flour bread (WWB) as a reference. The rye-based bread consisted of a WG rye kernel/flour mixture (1:1 ratio) supplemented with resistant starch type 2 (RS2) (RB + RS2). The last bread portion was ingested at 2100 h, and cognitive function, mood and cardiometabolic risk markers were determined the following morning, 11 − 14 h post intake.

Results

In comparison to WWB, the RB + RS2 product increased ratings of mood parameters (valance, P < 0.001; activation P < 0.05). No differences were seen in the cognitive tests depending on intervention (P > 0.05). RB + RS2 increased insulin sensitivity (P < 0.05), fasting levels of gut hormones (PYY, P < 0.05; GLP-2, P < 0.01) and fasting concentrations of plasma acetate, butyrate and total SCFA (P < 0.001). In contrast, fasting levels of IL − 1β were decreased (P < 0.05). Insulin sensitivity was positively correlated with working memory test performance (P < 0.05).

Conclusions

This study display novel findings regarding effects of WG rye products on mood, and glucose and appetite regulation in middle-aged subjects, indicating anti-diabetic properties of WG rye. The beneficial effects are suggested to be mediated through gut fermentation of dietary fiber in the RB + RS2 product.

Trial registration

The study was retrospectively registered at ClinicalTrials.gov, register number NCT03275948. Registered September 8 2017.

Parenting Intervention to Improve Nutrition and Physical Activity for Preschoolers with Type 1 Diabetes: A Feasibility Study

OBJECTIVE

This study reports the feasibility and acceptability of a healthy eating and physical-activity-focused behavioral intervention for parents of young children with type 1 diabetes (T1D).

METHODS

Ten parents of young children (age 2-5 years) with T1D enrolled. The intervention included six behavioral sessions (five by telephone), diabetes nursing consultation, parent coach contact, text messages, and a study website. Analyses explored feasibility, acceptability, and preliminary findings.

RESULTS

There was evidence of high acceptability (mean parent satisfaction = 1.11, very satisfied). Although most participants completed all of the assessments, there were some barriers to data collection devices. The number of participants within the American Diabetes Association recommended glycemic range doubled; there was no significant change in hemoglobin A1c, diet, or physical activity.

CONCLUSION

There was evidence of feasibility and acceptability and initial evidence of change in hypothesized directions. Minor changes were made for the larger randomized controlled trial.

Postprandial effects of breakfast glycaemic index on cognitive performance among young, healthy adults: A crossover clinical trial

Objective: To evaluate the postprandial effects of high and low glycaemic index (GI) breakfasts on cognitive performance in young, healthy adults.Methods: A crossover clinical trial including 40 young, healthy adults (aged 20-40 years, 50% females) recruited from primary healthcare centres in Salamanca, Spain. Verbal memory, phonological fluency, attention, and executive functions were examined 0, 60, and 120 minutes after consuming a low GI (LGI), high GI (HGI), or water breakfast. Every subject tried each breakfast variant, in a randomized order, separated by a washout period of 7 days, for a total of 3 weeks.Results: A significant interaction between the type of breakfast consumed and immediate verbal memory was identified (P<.05). We observed a trend towards better performance in verbal memory (delayed and immediate), attention, and phonological fluency following an LGI breakfast.Discussion: Cognitive performance during the postprandial phase in young, healthy adults was minimally affected by the GI of breakfast. The potential for breakfast's GI modulation to improve short- and long-term cognitive functioning requires further research.

Breakfast and behavior in morning tasks: Facts or fads?

BACKGROUND

Most of the studies investigating the effects of breakfast on cognitive performance have compared performance in subjects who have or have not consumed this meal. However, characteristics of breakfast itself may influence mental abilities. Moreover, as far as the positive effects of having breakfast is more evident, research may focus on the specific characteristics of an adequate breakfast.

METHODS

To update an existing systematic review, published at the beginning of 2014, on the role of nutrient composition and/or energy intake at breakfast on the accomplishment of school-related tasks and cognition, we carried out a systematic review of the literature through PUBMED database.

RESULTS

From the literature search, we identified 39 papers, of which 2 were eligible according to our inclusion criteria. Both the selected papers concerned randomized crossover studies on the acute effect of breakfast carried out in a school setting in the United Kingdom. Both studies compared 2 iso-energetic breakfasts with a similar macronutrient composition; however, the alternative breakfasts were meant to differ in terms of glycemic index or glycemic load. The effects of breakfast composition were investigated on memory, attention, and information processing in both studies. However, different tests and subdomains were considered.

LIMITATIONS

Studies on these issues are still inconsistent and quantitatively insufficient to draw firm conclusions.

CONCLUSIONS

While the hypothesis of a better mental performance with breakfast>20% daily energy intake still needs confirmation, there does appear to be extra evidence that a lower postprandial glycemic response is beneficial to mental performance.

Kiwifruit Non-Sugar Components Reduce Glycaemic Response to Co-Ingested Cereal in Humans

Kiwifruit (KF) effects on the human glycaemic response to co-ingested wheat cereal were determined. Participants (n = 20) consumed four meals in random order, all being made to 40 g of the same available carbohydrate, by adding kiwifruit sugars (KF sug; glucose, fructose, sucrose 2:2:1) to meals not containing KF. The meals were flaked wheat biscuit (WB)+KFsug, WB+KF, WB+guar gum+KFsug, WB+guar gum+KF, that was ingested after fasting overnight. Blood glucose was monitored 3 h and hunger measured at 180 min post-meal using a visual analogue scale. KF and guar reduced postprandial blood glucose response amplitude, and prevented subsequent hypoglycaemia that occurred with WB+KFsug. The area between the blood glucose response curve and baseline from 0 to 180 min was not significantly different between meals, 0–120 min areas were significantly reduced by KF and/or guar. Area from 120 to 180 min was positive for KF, guar, and KF+guar, while the area for the WB meal was negative. Hunger at 180 min was significantly reduced by KF and/or guar when compared with WB. We conclude that KF components other than available carbohydrate may improve the glycaemic response profile to co-ingested cereal food.

Macronutrient composition of a morning meal and the maintenance of attention throughout the morning

BACKGROUND

At present, the impact of macronutrient composition and nutrient intake on sustained attention in adults is unclear, although some prior work suggests that nutritive interventions that engender slow, steady glucose availability support sustained attention after consumption. A separate line of evidence suggests that nutrient consumption may alter electroencephalographic markers of neurophysiological activity, including neural oscillations in the alpha-band (8-14 Hz), which are known to be richly interconnected with the allocation of attention. It is here investigated whether morning ingestion of foodstuffs with differing macronutrient compositions might differentially impact the allocation of sustained attention throughout the day as indexed by both behavior and the deployment of attention-related alpha-band activity.

METHODS

Twenty-four adult participants were recruited into a three-day study with a cross-over design that employed a previously validated sustained attention task (the Spatial CTET). On each experimental day, subjects consumed one of three breakfasts with differing carbohydrate availabilities (oatmeal, cornflakes, and water) and completed blocks of the Spatial CTET throughout the morning while behavioral performance, subjective metrics of hunger/fullness, and electroencephalographic (EEG) measurements of alpha oscillatory activity were recorded.

RESULTS

Although behavior and electrophysiological metrics changed over the course of the day, no differences in their trajectories were observed as a function of breakfast condition. However, subjective metrics of hunger/fullness revealed that caloric interventions (oatmeal and cornflakes) reduced hunger across the experimental day with respect to the non-caloric, volume-matched control (water). Yet, no differences in hunger/fullness were observed between the oatmeal and cornflakes interventions.

CONCLUSION

Observation of a relationship between macronutrient intervention and sustained attention (if one exists) will require further standardization of empirical investigations to aid in the synthesis and replicability of results. In addition, continued implementation of neurophysiological markers in this domain is encouraged, as they often produce nuanced insight into cognition even in the absence of overt behavioral changes. ClinicalTrials.gov Identifier: NCT03169283.

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.

Whole dietary patterns to optimize cognitive function for military mission-readiness: a systematic review and recommendations for the field

Context

Optimizing cognitive performance, particularly during times of high stress, is a prerequisite to mission-readiness among military personnel. It has been of interest to determine whether such performance could be enhanced through diet.

Objective

This systematic review assesses the quality of the evidence for whole dietary patterns across various outcomes related to cognitive function in healthy adult populations to develop research recommendations for the military.

Data Sources

PubMed, CINAHL, Embase, PsycInfo, and the Cochrane Library were searched.

Study Selection

Peer-reviewed randomized controlled trials published in the English language were eligible.

Data Extraction

Fifteen included trials were assessed for methodological quality, and descriptive data were extracted.

Data Synthesis

Of the 6 acceptable-quality studies, 1 demonstrated statistically nonsignificant results, whereas the other 5 showed conflicting results across the cognitive outcomes assessed.

Conclusions

Due to the heterogeneity across the included studies, no recommendations could be reached concerning whether certain whole dietary patterns have an effect on cognitive outcomes in healthy populations. Specific recommendations for future research are offered.

The effect of environmental temperature on exercise-dependent release of brain-derived neurotrophic factor

Brain-derived neurotrophic factor (BDNF) is a biomarker of cognitive function that is released into the blood stream following exercise, and cognitive function is impaired by environmental temperatures that are hot and cold. Purpose: To evaluate the exercise-dependent release of BDNF in different environmental temperatures. Methods: Recreationally trained males each completed three trials consisting of cycling for 1 h at 60% Wmax at three different temperatures: 33°C (hot), 7°C (cold), and 20°C (moderate room temperature). Blood was taken from the antecubital vein pre-exercise, immediately post-exercise, and 3 h post-exercise. Respiratory gases were collected periodically throughout exercise and recovery. Results: BDNF was elevated immediately following an exercise bout (1711 ± 766 pg·ml-1) regardless of temperature from pre-exercise (1257 ± 653 pg·ml-1, p = 0.001) and returned to basal levels following 3 h of recovery (1289 ± 650 pg·ml-1, p = 0.786). There was no effect (p > 0.05) of temperature on BDNF following the exercise bout. Plasma glucose was elevated in hot (6.2 ± 0.9 mmol) over cold (5.3 ± 0.6 mmol, p = 0.035) and moderate room temperature (5.2 ± 0.5, p = 0.008). VO2 was elevated during exercise in hot (3.01 ± 0.45 L·min-1) over cold (2.67 ± 0.35 L·min-1, p = 0.005) and moderate room temperature (2.80 ± 0.38 L·min-1, p = 0.001). There was no relationship between BDNF and plasma glucose (p > 0.05) or VO2 across any time point or temperature (p > 0.05). Conclusion: With aerobic exercise, BDNF is elevated; however, the release of BDNF is not impacted by different environmental temperatures during exercise.

EEG and Eye Tracking Demonstrate Vigilance Enhancement with Challenge Integration

Maintaining vigilance is possibly the first requirement for surveillance tasks where personnel are faced with monotonous yet intensive monitoring tasks. Decrement in vigilance in such situations could result in dangerous consequences such as accidents, loss of life and system failure. In this paper, we investigate the possibility to enhance vigilance or sustained attention using “challenge integration,” a strategy that integrates a primary task with challenging stimuli. A primary surveillance task (identifying an intruder in a simulated factory environment) and a challenge stimulus (periods of rain obscuring the surveillance scene) were employed to test the changes in vigilance levels. The effect of integrating challenging events (resulting from artificially simulated rain) into the task were compared to the initial monotonous phase. EEG and eye tracking data is collected and analyzed for n = 12 subjects. Frontal midline theta power and frontal theta to parietal alpha power ratio which are used as measures of engagement and attention allocation show an increase due to challenge integration (p < 0.05 in each case). Relative delta band power of EEG also shows statistically significant suppression on the frontoparietal and occipital cortices due to challenge integration (p < 0.05). Saccade amplitude, saccade velocity and blink rate obtained from eye tracking data exhibit statistically significant changes during the challenge phase of the experiment (p < 0.05 in each case). From the correlation analysis between the statistically significant measures of eye tracking and EEG, we infer that saccade amplitude and saccade velocity decrease with vigilance decrement along with frontal midline theta and frontal theta to parietal alpha ratio. Conversely, blink rate and relative delta power increase with vigilance decrement. However, these measures exhibit a reverse trend when challenge stimulus appears in the task suggesting vigilance enhancement. Moreover, the mean reaction time is lower for the challenge integrated phase (RTmean = 3.65 ± 1.4s) compared to initial monotonous phase without challenge (RTmean = 4.6 ± 2.7s). Our work shows that vigilance level, as assessed by response of these vital signs, is enhanced by challenge integration.

The Effects of Breakfast and Breakfast Composition on Cognition in Adults

Extensive literature has addressed the acute cognitive effects of breaking a fast. Recent reviews in this line of work have synthesized available research on the cognitive consequences of fasting compared with nutrient intake and the cognitive effects of macronutrient consumption. These largely have been inconclusive, possibly in part because of selection criteria limiting the scope of studies covered. The purpose of the current review is to integrate the results of the literature examining the cognitive effects of breakfast and breakfast composition in adults with the use of a flexible definition of breakfast, specifically, any caloric intake after a fasting period of ≥8 h. This review includes 38 studies that examine the acute cognitive impact of breakfast and 16 studies that examine the effects of breakfast composition. Results suggest that healthy adults show a small but robust advantage for memory (particularly delayed recall) from consuming breakfast. Largely equivocal results emerge for attention and motor and executive function; there were no effects from breakfast on language. Regarding breakfast composition, a smaller number of studies and widely disparate methodology addressing this question preclude definitive conclusions about the effects of cognition. A subset of this literature examines these questions in the context of glucoregulation; the findings emphasize the importance of considering differences in glucoregulation in research designs, even among healthy cohorts. The limitations of this literature include methodologic differences, such as the use of different tests to measure cognitive constructs, as well as the effects of timing in test administration.

Post-prandial glucose and insulin responses of hummus alone or combined with a carbohydrate food: a dose-response study

Objectives

Pulses are low glycemic index (GI) foods and have been associated with reduced risk of heart disease, diabetes and some cancers. However the blood glucose and insulin responses of hummus, a food containing chickpea, have not been thoroughly tested.

Methods

Ten healthy subjects each consumed 11 breakfast study meals in randomized order over a period of 15 weeks. Hummus was consumed alone at three doses (2.7 g, 10.8 g and 25 g available carbohydrate [avCHO] portions) and with 50 g avCHO from white bread at three doses (2.7 g, 5.4 g and 10.8 g avCHO portions). The responses elicited by hummus alone were compared with 25 g avCHO portions of white bread, while those after hummus plus white bread were compared with 50 g avCHO from white bread. Plasma glucose and serum insulin responses were monitored over two hours and the GI and insulin index (II) calculated using standard methodology.

Results

The GI and II of hummus were 15 ± 3 and 52 ± 13, respectively, and were significantly lower than white bread (P < 0.05). The glucose and insulin incremental area under the curve (IAUC) for hummus alone were significantly lower than white bread except for insulin IAUC of hummus 25 g avCHO. The peak rise of blood glucose and insulin after hummus were significantly lower than after white bread. Glucose and insulin IAUC after adding hummus to bread did not differ significantly from white bread alone. However the blood glucose 45 min after adding 25 g avCHO from hummus to white bread was significantly lower while at 120 min it was significantly higher than after white bread alone.

Conclusions

This study demonstrated that, similar to chickpeas, hummus has a very low GI and II. Postprandial glucose responses were 4 times less than that of white bread and did not compromise insulin levels.

Effects of a carbohydrate-electrolyte solution on cognitive performance following exercise-induced hyperthermia in humans

BACKGROUND

There is limited information on the effects of sports drinks on cognitive function after exercise in the heat. We aimed to investigate the effects of ingesting a commercially available carbohydrate-electrolyte (CHO) solution on cognitive performance following exercise-induced hyperthermia.

METHODS

Twelve participants completed three practices of cognitive tests, one full familiarisation and two experimental trials in an environmental chamber (dry bulb temperature: 30.2 ± 0.3°C, relative humidity: 70 ± 3%). The experimental trials consisted of five cognitive tests (symbol digit matching, search and memory, digit span, choice reaction time and psychomotor vigilance test) performed before and after a 75-min run on a treadmill at 70% VO2 max. One ml/kg body mass of a 6.8% CHO solution or placebo was consumed at the start, every 15 min during exercise and between cognitive tests after exercise. Core temperature, heart rate, blood glucose concentrations, subjective ratings and cognitive performance were assessed (symbol digit matching, search and memory, digit span, choice reaction time and psychomotor vigilance).

RESULTS

Participants were hyperthermic at the end of the run (placebo: 39.5 ± 0.4°C, CHO: 39.6 ± 0.5°C; Mean ± SD; p = 0.37). The change in blood glucose was higher with CHO ingestion (1.6, 0.7 to 4.5 mmol/L) (median, range) than with placebo ingestion (0.9, -0.1 to 4.7 mmol/L; p < 0.05). CHO ingestion reduced the maximum span of digits memorized, in contrast to an increase in maximum span with placebo ingestion (p < 0.05). CHO solution had no effect on other cognitive tests (p > 0.05).

CONCLUSIONS

These results suggest that CHO solution ingestion may impair short-term memory following exertional heat stress.

A low glycaemic load breakfast can attenuate cognitive impairments observed in middle aged obese females with impaired glucose tolerance

BACKGROUND AND AIMS

There has been no systematic investigation of the individual and combined effects of impaired glucose tolerance (IGT) and obesity on cognitive function in the absence of ageing. The aims were to examine the effects of IGT and increased waist circumference on cognitive function in ostensibly healthy adults, and to investigate whether a low glycaemic load (GL) breakfast can attenuate cognitive impairments in these populations.

METHODS AND RESULTS

Sixty five females aged 30-50 years were classified into one of four groups following waist circumference (WC) measurements and an oral glucose tolerance test: NGT/low WC (n = 25), NGT/high WC (n = 22), IGT/low WC (n = 9), IGT/high WC (n = 9). Memory, psychomotor and executive functions were examined 30 and 120 min after consuming low GL, high GL and water breakfasts according to a randomised, crossover, counterbalanced design. IGT was associated with impairment of verbal and spatial memory, and psychomotor function relative to females with NGT, independent of waist circumference. Increased waist circumference was associated with impairment of verbal memory and executive function relative to females with low WC, independent of IGT. Consumption of the LGL breakfast attenuated verbal memory impairment in the IGT/high WC group relative to the HGL breakfast and no energy control.

CONCLUSION

Increased central adiposity and abnormalities in glucose tolerance preceding type 2 diabetes can have demonstrable negative effects on cognitive function, even in ostensibly healthy, middle-aged females. The potential for GL manipulations to modulate glycaemic response and cognitive function in type 2 diabetes and obesity merits further investigation.

The effect of breakfast composition and energy contribution on cognitive and academic performance: a systematic review

BACKGROUND

Most studies that assess the effects of breakfast on subsequent mental abilities compared performance in subjects who had or had not consumed this meal. However, characteristics of breakfast itself may induce metabolic and hormonal alterations of the gastrointestinal tract and potentially modify cognitive performance. Moreover, as far as the evidence on the positive effects of having breakfast is becoming more robust, interest may shift to the specific characteristics of an adequate breakfast.

OBJECTIVE

The objective was to summarize existing evidence on the role of nutrient composition or energy intake at breakfast on the accomplishment of school-related tasks and cognition.

DESIGN

We conducted a systematic review of the literature through the PubMed database.

RESULTS

From the literature search, we identified 102 articles, 15 of which met the inclusion criteria. Of these, 3 studies provided information on the relation between cognitive and academic performance and energy intake at breakfast, 11 provided the same information for the macronutrient composition of breakfast, and 1 investigated both the aspects. Eleven studies considered breakfast meals differing in glycemic index/load. Selected studies were generally carried out in well-nourished children and adults of both sexes from general education. They were mostly experimental studies of short duration and had a limited number of subjects. Cognitive and academic performance was investigated by looking at multiple domains, including memory, attention, reasoning, learning, and verbal and math abilities, with a variety of test batteries scheduled at different time points in the morning. Breakfast options differed in terms of included foods and place and time of administration.

CONCLUSIONS

There is insufficient quantity and consistency among studies to draw firm conclusions. However, whereas the hypothesis of a better and more sustained performance with a breakfast providing >20% daily energy intake still needs substantiation, there does appear to be emerging, but still equivocal, evidence that a lower postprandial glycemic response is beneficial to cognitive performance.

Impact of insulins glulisine and aspart on postprandial glycemia after a high-glycemic index meal in children with type 1 diabetes

OBJECTIVE

According to current knowledge, glulisine insulin (GLU) has a slightly faster onset of action than aspart (ASP) insulin. Therefore, GLU might lead to a better postprandial profile than ASP following the consumption of high-glycemic index (H-GI) meals. The aim of this study was to assess differences in the action of GLU and ASP after the consumption of a H-GI meal in type 1 diabetic children treated with insulin pumps.

DESIGN

FIFTY-SIX TYPE 1 DIABETIC CHILDREN OF MEAN AGE 14.72.0 YEARS WERE INCLUDED IN A RANDOMIZED, DOUBLE-BLIND, TWO-WAY CROSSOVER STUDY.

THE SUBJECTS WERE ALLOCATED TO ONE OF TWO TREATMENT ORDERS

GLU-ASP and ASP-GLU. They were given a H-GI breakfast for two subsequent days.

METHODS

The primary outcome was postprandial glycemia (PPG) based on continuous glucose monitoring system and self monitoring of blood glucose levels during 3 h of follow-up. The secondary outcomes were the frequency of hypoglycemia, glucose area under the curve, mean amplitude of glycemic excursion, and glycemic rise.

RESULTS

THERE WERE NO SIGNIFICANT DIFFERENCES BETWEEN THE GROUPS WITH REGARD TO PPG IN THE DETERMINED TIME INTERVALS AS WELL AS WITH RESPECT TO THE SECONDARY OUTCOMES. BETWEEN 60 AND 120MIN AFTER FOOD CONSUMPTION IN BOTH STUDY GROUPS, BLOOD GLUCOSE LEVELS WERE CLOSE TO OR ABOVE 10.0MMOL/L. GLUCOSE PEAKS WERE HIGHER IN THE GLUASP GROUP THAN IN THE ASPGLU GROUP (90MIN: P=0.065; 120 min: P=0.052). Most of the episodes of hypoglycemia were observed after the second hour of follow-up.

CONCLUSIONS

No statistically significant difference was found between GLU and ASP with regard to PPG after the consumption of a H-GI breakfast. Neither GLU nor ASP stabilized the glycemic profile after the consumption of a H-GI meal.

The influence of glycemic index on cognitive functioning: a systematic review of the evidence

The impact of the rate of carbohydrate absorption, as measured by the carbohydrate's glycemic index (GI) on cognitive performance, is not clear. The aim of this review was to systematically assess the relevant research studies. A systematic review of English-language articles using Medline, Cochrane Central Register of Controlled Trials, EMBASE, PsycINFO, and PsycARTICLES (up to July 2012) using the search terms "glyc(a)emic index" or "glycaemic load" combined with "cognitive function" or "cognition" or "memory" was carried out. Inclusion and exclusion criteria were prespecified. Eligibility of the identified studies was assessed independently by the 2 reviewers. Independent extraction of data was carried out by the 2 authors using predefined data fields. The primary outcome measure was the effect on cognitive function (CF) after the consumption of meals varying in GI. Eleven eligible studies were identified. The age range of the participants varied from 6 to 82 y old. Overall, the findings were inconsistent, with some studies showing benefits toward either the high-GI or the low-GI meal, others not finding any differences between the 2 meals, and other studies showing a positive or negative effect on performance on only some cognitive domain or domains after consumption of 1 of the 2 meals. A number of methodologic and confounding factors were identified that could explain these inconsistencies. These include the study design, the selected sample (size, age, blood glucose regulation), the timing of testing, the cognitive domain being examined, the number and type of cognitive tests used, the meals provided (composition, size), the timing of blood samples collected, as well as the possibility of bias because participants and investigators were not blinded to randomization. A low-GI meal may favor CF in adults, but the findings at present are inconclusive. On the basis of this review, it is suggested that future studies address the identified methodologic issues and some recommendations are proposed to this effect.

Young children with type 1 diabetes: challenges, research, and future directions

The incidence of type 1 diabetes (T1D) in young children (age <6 years) is rising. Diabetes management guidelines offered by the American Diabetes Association and health care teams understandably place a high burden of responsibility on caregivers to check young children's blood glucose levels, administer insulin, and monitor diet and physical activity with the ultimate goal of maintaining tight glycemic control. Unfortunately, this tight control is needed during a vulnerable developmental period when behavior is unpredictable, T1D can be physiologically difficult to control, parenting stress can be elevated, and caregivers are strained by normal child caretaking routines. Despite the potentially different management needs, specific education and clinical services for managing diabetes in young children are rarely offered, and behavioral research with this young child age group has been limited in scope and quantity. Research findings pertinent to young children with T1D are reviewed, and potential clinical implications, as well as areas for future research, are discussed.

Designing future prebiotic fiber to target metabolic syndrome

The metabolic syndrome (MetS), characterized by obesity, hyperlipidemia, hypertension, and insulin resistance, is a growing epidemic worldwide, requiring new prevention strategies and therapeutics. The concept of prebiotics refers to selective stimulation of growth and/or activity(ies) of one or a limited number of microbial genus(era)/species in the gut microbiota that confer(s) health benefits to the host. Sequencing the gut microbiome and performing metagenomics has provided new knowledge of the significance of the composition and activity of the gut microbiota in metabolic disease. As knowledge of how a healthy gut microbiota is composed and which bacterial metabolites are beneficial increases, tailor-made dietary interventions using prebiotic fibers could be developed for individuals with MetS. In this review, we describe how dietary fibers alter short-chain fatty acid (SCFA) profiles and the intrinsic and extrinsic effects of prebiotics on host metabolism. We focus on several key aspects in prebiotic research in relation to MetS and provide mechanistic data that support the use of prebiotic fibers in order to alter the gut microbiota composition and SCFA profiles. Further studies in the field should provide reliable mechanistic and clinical evidence for how prebiotics can be used to alleviate MetS and its complications. Additionally, it will be important to clarify the effect of individual differences in the gut microbiome on responsiveness to prebiotic interventions.

A diet based on multiple functional concepts improves cognitive performance in healthy subjects

Background

Disorders such as the metabolic syndrome (MetS), impaired glucose tolerance and diabetes, are associated with increased risk of cognitive decline. Also several of the individual key features that define the MetS, e.g. hypertension, impaired glucose regulation, dyslipidemia, obesity, and inflammation, are related to an increased risk of cognitive decline. Consequently, a diet that prevents metabolic disorders might be expected to prevent cognitive decline. The purpose of the present study was to, in overweight but otherwise healthy subjects, investigate effects on cognitive functions of a dietary regime combining multiple functional concepts potentially beneficial to risk markers associated with MetS. The purpose was in addition to evaluate cognitive performance in relation to results on cardiometabolic risk variables (BMI, blood pressure, glucose, insulin, cholesterol, triglycerides, free fatty acids, lipoprotein A-1 and B, hs-CRP, HbA1c, interleukin-6, TNF-α, and PAI-1).

Methods

Fourty-four healthy women and men (50–73 years, BMI 25–33, fasting glycemia ≤ 6.1 mmol/L) participated in a randomized, controlled crossover intervention, comparing a multifunctional diet (active diet (AD)) including foods with a potential anti-inflammatory action, with a control diet (CD) devoid of the “active” components. Both diets were composed in close agreement with the Nordic dietary recommendations. Each diet was consumed during 4 wk, separated by a 4 wk washout period. Cognitive tests were performed at fasting and in the postprandial period after a standardized breakfast, after each diet period.

Results

In comparison with the CD, the AD improved performance in the Rey Auditory-Verbal Learning test (recognition test, p < 0.05, ANOVA, n = 42) and significantly improved performance in test of selective attention, which also included aspects of working memory (p < 0.05, n = 40). Performance in cognitive tests was inversely associated with plasma concentrations of cardiometabolic risk markers (fasting cholesterol, blood glucose, blood pressure) and cardiovascular risk scores (Framingham and Reynols), and positivly associated with apolipoprotein A1 (p < 0.05).

Conclusions

The results indicate that diet characteristics may modulate cognitive performance. A relationship seems to exist between cardiometabolic risk markers and cognitive performance in apparently healthy subjects. The results provide additional motives for diet based prevention of metabolic disturbances related to the MetS.

Formation of short-chain Fatty acids, excretion of anthocyanins, and microbial diversity in rats fed blackcurrants, blackberries, and raspberries

Introduction. Berries contain high amounts of dietary fibre and flavonoids and have been associated with improved metabolic health. The mechanisms are not clear but the formation of SCFAs, especially propionic and butyric acids, could be important. The potent antioxidant and antimicrobial properties of flavonoids could also be a factor, but little is known about their fate in the gastrointestinal tract. Aim. To compare how blackcurrants, blackberries, raspberries, and Lactobacillus plantarum HEAL19 affect formation of SCFAs, inflammatory status, caecal microbial diversity, and flavonoids. Results and Conclusions. Degradation of the dietary fibre, formation of SCFAs including propionic and butyric acids, the weight of the caecal content and tissue, and the faecal wet and dry weight were all higher in rats fed blackcurrants rather than blackberries or raspberries. However, the microbial diversity of the gut microbiota was higher in rats fed raspberries. The high content of soluble fibre in blackcurrants and the high proportion of mannose-containing polymers might explain these effects. Anthocyanins could only be detected in urine of rats fed blackcurrants, and the excretion was lower with HEAL19. No anthocyanins or anthocyanidins were detected in caecal content or blood. This may indicate uptake in the stomach or small intestine.