The Effects of Carbohydrates, in Isolation and Combined with Caffeine, on Cognitive Performance and Mood-Current Evidence and Future Directions

Caffeine intake and its association with nutrition, sleep, and physical activity among schoolchildren in the United Arab Emirates: a national cross-sectional study

PURPOSE

Recent surveys indicate a significant increase in total caffeine intake among schoolchildren. Limited research has been published concerning the total intake of caffeine among schoolchildren in the Middle East and Gulf Cooperation Council (GCC) countries, including the UAE.

METHODS

This cross-sectional survey estimated the total caffeine intake from foods and beverages among 10,275 schoolchildren in the UAE. Caffeine intakes were related to the European Food Safety Authority's level of no safety concern (3.0 mg/kg BW) and level of effects on sleep (1.4 mg/kg BW).

RESULTS

More than half (56.2%) of the students consumed more than 100 mg (the upper limit allowed) of caffeine from dietary sources. High intake of caffeine (> 100 mg/day) was significantly associated (p = 0.001) with reduced sleep duration, difficulty falling asleep, infrequent exercising, using smart devices for more than 2 h a day, getting a lower GPA, skipping breakfast, eating fewer servings of vegetables than recommended, frequent consumption of fast food and more frequent snack consumption.

CONCLUSION

Excessive intake of caffeine from different dietary sources coexists with unhealthy dietary and lifestyle behaviors and sleep problems. Tailoring educational programs and intervention strategies is warranted to correct the unhealthy intake of caffeine and the associated unhealthy dietary and lifestyle behaviors among schoolchildren in the UAE.

Comparing the effects of dietary sugars on cognitive performance and reaction time: A randomized, placebo- controlled and double-blind experimental trial

The aim of the study was to compare the effects of acute intake dietary sugars on cognitive performance and reaction time. This study was, randomized, placebo-controlled, double-blind experimental design, conducted with 75 healthy adults. At the beginning of the study, the participants (36 male, 39 female; 21.6 ± 1.3 years of age; body mass index: 21.59 ± 1.94 kg/m²) were randomly divided into equal five groups (n:15) (glucose (10 g), fructose (10 g), sucrose (10 g), saccharin (0.24 g), placebo), and received dietary sugars dissolved in 200 mL of water. Cognitive performance was determined with Cancelation Test, and the Simple Response Time and Ruler Drop Tests were used in order to response and reaction time of participants, respectively. General score of cognitive performance (0.93 ± 0.1), reaction (295 ± 20 ms), and response (204 ms) were highest in glucose and lowest in placebo (0.63 ± 0.1; 368 ± 22 ms; 251 ms, respectively) (p < .001). Saccharin groups had a higher reaction (312 ± 22 ms) and response (216 ms) time score compared to consumed fructose (316 ± 39; 227 ms), sucrose (354 ± 26; 246 ms), and placebo (368 ± 22; 251 ms) groups, respectively (p < .001). These findings show that differences in the absorption pattern and sweetness levels of sugar types may have different effects on cognitive performance and reaction time.

The Burden of Carbohydrates in Health and Disease

Foods high in carbohydrates are an important part of a healthy diet, since they provide the body with glucose to support bodily functions and physical activity. However, the abusive consumption of refined, simple, and low-quality carbohydrates has a direct implication on the physical and mental pathophysiology. Then, carbohydrate consumption is postulated as a crucial factor in the development of the main Western diseases of the 21st century. We conducted this narrative critical review using MedLine (Pubmed), Cochrane (Wiley), Embase, and CinAhl databases with the MeSH-compliant keywords: carbohydrates and evolution, development, phylogenetic, GUT, microbiota, stress, metabolic health, consumption behaviors, metabolic disease, cardiovascular disease, mental disease, anxiety, depression, cancer, chronic kidney failure, allergies, and asthma in order to analyze the impact of carbohydrates on health. Evidence suggests that carbohydrates, especially fiber, are beneficial for the well-being and growth of gut microorganisms and consequently for the host in this symbiotic relationship, producing microbial alterations a negative effect on mental health and different organic systems. In addition, evidence suggests a negative impact of simple carbohydrates and refined carbohydrates on mood categories, including alertness and tiredness, reinforcing a vicious circle. Regarding physical health, sugar intake can affect the development and prognosis of metabolic disease, as an uncontrolled intake of refined carbohydrates puts individuals at risk of developing metabolic syndrome and subsequently developing metabolic disease.

Food Reward Alterations during Obesity Are Associated with Inflammation in the Striatum in Mice: Beneficial Effects of Akkermansia muciniphila

The reward system involved in hedonic food intake presents neuronal and behavioral dysregulations during obesity. Moreover, gut microbiota dysbiosis during obesity promotes low-grade inflammation in peripheral organs and in the brain contributing to metabolic alterations. The mechanisms underlying reward dysregulations during obesity remain unclear. We investigated if inflammation affects the striatum during obesity using a cohort of control-fed or diet-induced obese (DIO) male mice. We tested the potential effects of specific gut bacteria on the reward system during obesity by administrating Akkermansia muciniphila daily or a placebo to DIO male mice. We showed that dysregulations of the food reward are associated with inflammation and alterations in the blood–brain barrier in the striatum of obese mice. We identified Akkermansia muciniphila as a novel actor able to improve the dysregulated reward behaviors associated with obesity, potentially through a decreased activation of inflammatory pathways and lipid-sensing ability in the striatum. These results open a new field of research and suggest that gut microbes can be considered as an innovative therapeutic approach to attenuate reward alterations in obesity. This study provides substance for further investigations of Akkermansia muciniphila-mediated behavioral improvements in other inflammatory neuropsychiatric disorders.

The possible mediatory role of adipokines in the association between low carbohydrate diet and depressive symptoms among overweight and obese women

BACKGROUND

Previous studies showed the possible association between obesity, dietary pattern, and depressive symptoms. Due to the lack of enough data to confirm the association of obesity and depression in the Middle East, here, we aimed to explore the possible mediatory role of adipokines Galectin-3, transforming growth factor-beta (TGF-β), and endothelial plasminogen activator inhibitor (PAI-1) in the association between low carbohydrate diet (LCD) and depressive symptoms.

METHODS

A total of 256 women aged 17-56 years old were grouped based on their LCD score. Depression anxiety stress scales-21 (DASS-21) self-administered questionnaire was used to evaluate the three negative emotional states of stress, depressive symptoms, and anxiety. Body composition and dietary intake were assessed. Enzyme-linked immunosorbent assay (ELISA) was used to measure the serum levels of Galectin-3, TGF-β, and PAI-1.

RESULTS

No significant difference was observed regarding Galectin-3, TGF-β, and PAI-1 levels between the groups with dissimilar adherence to LCD or the groups with different levels of depressive symptoms (P>0.05). However, there was a negative association between LCD score as a covariant and depressive symptoms as an independent variable (P = 0.02) and remarkably, a regression model linear analysis using Galectin-3, TGF-β, and PAI-1 as confounding variables indicated the mediatory role of these adipokines in this association (P>0.05). In other words, adipokines eliminated the significance of the relationship between adherence to LCD and depressive symptoms.

CONCLUSION

It seems that higher adherence to LCD is probably associated with a lower prevalence of depressive symptoms in obese adults through the mediatory role of adipokines.

Association of Family Nutrition and Physical Activity with Preschooler's Working Memory: A Cross-Sectional Study among Mexican Children

Healthy eating and active lifestyles are associated with children’s healthy weight and cognitive development. This study examines whether family behaviors relevant for nutrition and activity levels are associated with children’s working memory, independent of their weight status. A convenience sample of child–caregiver dyads (n = 85 dyads) were recruited from a public preschool serving a low-income community in central Mexico. Caregivers reported the frequency of ten family behaviors using the Family Nutrition and Physical Activity screening tool. Children completed a test of their ability to recall four words after a 60-s distraction task, an assessment of working memory. Multiple linear regression models were used to test the association of children’s working memory with each family behavior, adjusting for children’s sex, age, mother’s age and education, and subjective social status and then also adjusting for children’s age- and sex-specific body mass index percentile (BMI-P) and covariates. Higher frequency of breakfast intake was significantly associated with working memory (β = 0.57, p = 0.013). This association was independent of children’s BMI-P. Other family behaviors (frequent family mealtimes, limiting screen time, and others) were not significantly associated with children’s working memory. Frequent breakfast intake could benefit young children’s working memory, regardless of their weight status. This association merits further investigation.

Stimulant Usage by Medical Students for Cognitive Enhancement: A Systematic Review

Stimulants have been used throughout human history for a variety of reasons. High levels of stress and the demanding nature of medical school make their usage among medical students particularly common. The most prevalent stimulant used by students is coffee, followed by tea and other forms of caffeine like sugary energy drinks. In addition, amphetamine-based medications for treating attention deficit hyperactivity disorder (ADHD) have been increasing in popularity, which many students take illicitly. Students report taking various forms of stimulants to promote cognitive enhancement, prolong wakefulness and retain focus for long periods of time. Moderate doses of caffeine and amphetamines would lead to enhanced alertness and concentration. However, large increases in dosage or frequency would lead to an increased risk of toxicity and adverse effects. The positive outcomes from stimulant consumption are often overshadowed by the negative side effects and incorrect dosage. Thus, it appears that usage of stimulants should be limited, in favor of a more sustainable approach to cognitive enhancement. This review analyzes the use of stimulants among the medical student community, consequences of misuse and discussed the healthy and organic approaches to lessen the stress and improve academic performance. This article also discusses the mechanisms of action, acceptable doses, additives, ingredients of stimulants commonly used by medical students for cognitive enhancement and the implications of long-term use as the stress of practicing medicine extends well beyond the medical school years.

Varying roles of glucoregulatory function measures in postprandial cognition following milk consumption

PURPOSE

Past work suggests milk consumption may facilitate cognition in children and college students with higher fasting glucose compared to other beverages (e.g., fruit juice). However, no studies have evaluated this phenomenon in adults, or considered other measures of glucoregulatory function. This open-label study assessed the role of glucoregulatory function in postprandial cognition after milk intake in adults. We hypothesized participants with lower fasting or post-consumption plasma glucose following a glucose excursion challenge (glucose response) would demonstrate better cognition following beverages of higher (juice) versus lower (milk) or no (water) glycemic content.

METHODS

Forty-four nondiabetic, overnight-fasted adults attended three laboratory visits, ingesting 237 mL of 2% fat milk, apple juice, or water at each visit in a randomized, counterbalanced, crossover design. Participants completed cognitive testing (CNS Vital Signs) at baseline and 30, 90, and 150 min post-ingestion; primary outcomes were CNS Vital Signs composite scores. Fasting and post-consumption plasma glucose levels were assessed, with glucose response indexed as the change in plasma glucose from baseline to 30 min after juice (ΔGlucose).

RESULTS

Mixed modeling revealed participants with higher fasting glucose demonstrated better complex attention after water versus juice at 30 min, but better performance after juice versus water at 150 min (p = 0.02). Participants with a larger ΔGlucose demonstrated better processing speed (p = 0.01) 30 min after milk versus water; this effect also reversed at 150 min.

CONCLUSION

Different methods of measuring glucoregulatory function reveal its differing roles in postprandial cognition. Time since ingestion may also determine which beverages best optimize cognition.

Prevalence and Perceived benefits of energy drink Consumption in medical students

Background: To assess the energy drink consumption patterns and perceived risks and benefits among medical students. The present study was carried out on 332 medical students from Foundation University Medical College. All the students enrolled in foundation university medical college were invited to participate. 332 students, who gave their consent were enrolled in the study. Data was collected by distributing a preformed structured questionnaire among medical students present in their classes. Data was entered and analyzed on SPSS version 17. Results: Out of 332 students 307 (92.5%) said that they were familiar with energy drinks whereas 212 (63.9%) admitted to consuming energy drinks. sting and the red bull came out to be the most popular brands. 78 (36.7%) students said mental awareness to be the main motivator for energy drink consumption. The majority (94.3%) of the study population were aware of the untoward effects of energy drinks experienced. The most common of them was insomnia, students (49.05%) experienced it. 91 (42.92%) of the students said that their parents don’t object to their taking of these drinks. Conclusion: Although the consumption of energy drinks was common among medical students, the knowledge of ingredients and health risks of energy drinks among them was unsatisfactory. Keywords: Energy drink, Medical students, Caffeine, Frequency of consumption.

Sugar rush or sugar crash? A meta-analysis of carbohydrate effects on mood

The effect of carbohydrate (CHO) consumption on mood is much debated, with researchers reporting both mood improvements and decrements following CHO ingestion. As global consumption of sugar-sweetened products has sharply increased in recent years, examining the validity of claims of an association between CHOs and mood is of high importance. We conducted a systematic review and meta-analysis to evaluate the relationship between acute CHO ingestion and mood. We examined the time-course of CHO-mood interactions and considered the role of moderator variables potentially affecting the CHO-mood relationship. Analysis of 176 effect sizes (31 studies, 1259 participants) revealed no positive effect of CHOs on any aspect of mood at any time-point following their consumption. However, CHO administration was associated with higher levels of fatigue and less alertness compared with placebo within the first hour post-ingestion. These findings challenge the idea that CHOs can improve mood, and might be used to increase the public's awareness that the 'sugar rush' is a myth, inform health policies to decrease sugar consumption, and promote healthier alternatives.

Predictors of Source Memory Success and Failure in Older Adults

Source memory decline has been identified as one of the types of memory most seriously affected during older age. It refers to our capacity to recollect the contextual information in which our experiences take place. Although most elderly adults will be affected by progressive source memory decline, a subset of individuals will not follow this average pattern; instead, their source memory capabilities will remain functional. Likewise, a minority of individuals will manifest an extreme decay of their source memory abilities. The objective of the present study was to identify among 120 potential predictors that significantly contributed to these two extreme source memory outcomes. Spatial source memory was measured in a sample of 519 healthy individuals between 61 and 80 years old. Individuals who performed below the 20th and above the 80th percentiles in the source memory task were defined as individuals whose episodic memory failed and succeeded, respectively. Logistic models identified five and six significant predictors of source memory success and failure in older age, respectively. High source memory performance was mainly predicted by healthy cardiovascular markers and psychological traits, whereas low source memory performance was primarily predicted by consumption habits and by less engagement in mental activities. The models identified relevant biological and life experiences that underlie these unusual source memory outcomes in older age.