-
1.
A Systematic Review of the Effect of Dietary Supplements on Cognitive Performance in Healthy Young Adults and Military Personnel.
Pomeroy, DE, Tooley, KL, Probert, B, Wilson, A, Kemps, E
Nutrients. 2020;(2)
Abstract
Intake of dietary supplements has increased, despite evidence that some of these have adverse side effects and uncertainty about their effectiveness. This systematic review examined the evidence for the cognitive benefits of a wide range of dietary supplements in healthy young adult samples; the aim was to identify if any might be useful for optimising cognitive performance during deployment in military personnel. Searches were conducted in 9 databases and 13 grey literature repositories for relevant studies published between January 2000 and June 2017. Eligible studies recruited healthy young adults (18-35 years), administered a legal dietary supplement, included a comparison control group, and assessed cognitive outcome(s). Thirty-seven of 394 identified studies met inclusion criteria and were included for synthesis. Most research was deemed of low quality (72.97%; SIGN50 guidelines), highlighting the need for sound empirical research in this area. Nonetheless, we suggest that tyrosine or caffeine could be used in healthy young adults in a military context to enhance cognitive performance when personnel are sleep-deprived. Caffeine also has the potential benefit of improving vigilance and attention during sustained operations offering little opportunity for sleep. Inconsistent findings and methodological limitations preclude firm recommendations about the use of other specific dietary supplements.
-
2.
Cognitive Distraction at Mealtime Decreases Amount Consumed in Healthy Young Adults: A Randomized Crossover Exploratory Study.
Liguori, CA, Nikolaus, CJ, Nickols-Richardson, SM
The Journal of nutrition. 2020;(5):1324-1329
-
-
Free full text
-
Abstract
BACKGROUND Environmental distractions have been shown to affect eating patterns. OBJECTIVE The purpose of this study was to determine the effects of a cognitive distraction on amount, preference, and memory of food consumed and perceptions of fullness, hunger, and enjoyment of food in a healthy young-adult population. METHODS A randomized controlled crossover study of 119 healthy adults (20.2 ± 1.4 y; 57% women; 48% white) assigned participants to begin under either the distracted (DIS, n = 55) or control (CON, n = 64) conditions. DIS participants consumed a meal of quiche while completing a Rapid Visual Information Processing (RVIP) for 15 min. CON participants ate without any task assignment. After a 30-min rest period, participants were offered a snack and given 5 min to eat ad libitum. Participants completed a survey assessing fullness, hunger, and enjoyment of the meal using 100 mm visual analogue scales. One week later, participants completed the opposite condition. Data were analyzed using ANOVA. RESULTS Those in DIS consumed 13 g less of the meal (P < 0.001), even when comparing by initial condition (P < 0.001) and adjusting for sex (P < 0.001). A carryover effect of initial condition was found (P < 0.001), such that participants first assigned to DIS condition consumed less (95.2 ± 61.7 g) when distracted compared to all other condition combinations (127-133 g). Those in DIS had decreased accuracy for both memory of quiche received (absolute difference, 1.1 ± 1.6 compared with 0.7 ± 1.2 for CON, P < 0.001) and memory of quiche consumed (0.8 ± 1.1 for DIS compared with 0.7 ± 1.2 for CON, P = 0.007). CONCLUSIONS When distracted, healthy young adults consumed significantly less food and their memory of the meal was dampened. These findings underscore the potential importance of cognitive distraction in affecting food intake. This trial was registered at clinicaltrials.gov as NCT04078607.
-
3.
The use of commercial computerised cognitive games in older adults: a meta-analysis.
Bonnechère, B, Langley, C, Sahakian, BJ
Scientific reports. 2020;(1):15276
Abstract
Brain training programs are currently one effective solution to prevent cognitive decline in healthy aging. We conducted a meta-analysis of randomized controlled trials assessing the use of commercially available computerised cognitive games to improve cognitive function in people aged above 60 years old without cognitive impairment. 1,543 participants from sixteen studies were included in the meta-analysis. Statistically significant improvements were observed for processing speed (SMD increased 0.40 [95% CI 0.20-0.60], p < 0.001), working memory (0.21 [95% CI 0.08-0.34], p = 0.001), executive function (0.21 [95% CI 0.06-0.35], p = 0.006), and for verbal memory (0.12 [95% CI 0.01-0.24, p = 0.031), but not for attention or visuospatial abilities. No relationship between the age of the participants and the amount of training was found. Commercially available computerised cognitive games are effective in improving cognitive function in participants without cognitive impairment aged over 60 years.
-
4.
Phosphodiesterase as a Target for Cognition Enhancement in Schizophrenia.
Al-Nema, MY, Gaurav, A
Current topics in medicinal chemistry. 2020;(26):2404-2421
Abstract
Schizophrenia is a severe mental disorder that affects more than 1% of the population worldwide. Dopamine system dysfunction and alterations in glutamatergic neurotransmission are strongly implicated in the aetiology of schizophrenia. To date, antipsychotic drugs are the only available treatment for the symptoms of schizophrenia. These medications, which act as D2-receptor antagonist, adequately address the positive symptoms of the disease, but they fail to improve the negative symptoms and cognitive impairment. In schizophrenia, cognitive impairment is a core feature of the disorder. Therefore, the treatment of cognitive impairment and the other symptoms related to schizophrenia remains a significant unmet medical need. Currently, phosphodiesterases (PDEs) are considered the best drug target for the treatment of schizophrenia since many PDE subfamilies are abundant in the brain regions that are relevant to cognition. Thus, this review aims to illustrate the mechanism of PDEs in treating the symptoms of schizophrenia and summarises the encouraging results of PDE inhibitors as anti-schizophrenic drugs in preclinical and clinical studies.
-
5.
Acute and Chronic Effects of Green Oat (Avena sativa) Extract on Cognitive Function and Mood during a Laboratory Stressor in Healthy Adults: A Randomised, Double-Blind, Placebo-Controlled Study in Healthy Humans.
Kennedy, DO, Bonnländer, B, Lang, SC, Pischel, I, Forster, J, Khan, J, Jackson, PA, Wightman, EL
Nutrients. 2020;(6)
Abstract
Green oat (Avena sativa) extracts contain several groups of potentially psychoactive phytochemicals. Previous research has demonstrated improvements in cognitive function following a single dose of these extracts, but not following chronic supplementation. Additionally, whilst green oat extracts contain phytochemicals that may improve mood or protect against stress, for instance species-specific triterpene saponins, to date this possibility has not been examined. The current study investigated the effects of a single dose and four weeks of administration of a novel, Avena sativa herbal extract (cognitaven®) on cognitive function and mood, and changes in psychological state during a laboratory stressor. The study adopted a dose-ranging, double-blind, randomised, parallel groups design in which 132 healthy males and females (35 to 65 years) received either 430 mg, 860 mg, 1290 mg green oat extract or placebo for 29 days. Assessments of cognitive function, mood and changes in psychological state during a laboratory stressor (Observed Multitasking Stressor) were undertaken pre-dose and at 2 h and 4 h post-dose on the first (Day 1) and last days (Day 29) of supplementation. The results showed that both a single dose of 1290 mg and, to a greater extent, supplementation for four weeks with both 430 mg and 1290 mg green oat extract resulted in significantly improved performance on a computerised version of the Corsi Blocks working memory task and a multitasking task (verbal serial subtractions and computerised tracking) in comparison to placebo. After four weeks, the highest dose also decreased the physiological response to the stressor in terms of electrodermal activity. There were no treatment-related effects on mood. These results confirm the acute cognitive effects of Avena sativa extracts and are the first to demonstrate that chronic supplementation can benefit cognitive function and modulate the physiological response to a stressor.
-
6.
Benefits and Harms of Prescription Drugs and Supplements for Treatment of Clinical Alzheimer-Type Dementia.
Fink, HA, Linskens, EJ, MacDonald, R, Silverman, PC, McCarten, JR, Talley, KMC, Forte, ML, Desai, PJ, Nelson, VA, Miller, MA, et al
Annals of internal medicine. 2020;(10):656-668
-
-
Free full text
-
Abstract
BACKGROUND Effects of drug treatment of clinical Alzheimer-type dementia (CATD) are uncertain. PURPOSE To summarize evidence on the effects of prescription drugs and supplements for CATD treatment. DATA SOURCES Electronic bibliographic databases (inception to November 2019), ClinicalTrials.gov (to November 2019), and systematic review bibliographies. STUDY SELECTION English-language trials of prescription drug and supplement treatment in older adults with CATD that report cognition, function, global measures, behavioral and psychological symptoms of dementia (BPSD), or harms. Minimum treatment was 24 weeks (≥2 weeks for selected BPSD). DATA EXTRACTION Studies with low or medium risk of bias (ROB) were analyzed. Two reviewers rated ROB. One reviewer extracted data; another verified extraction accuracy. DATA SYNTHESIS Fifty-five studies reporting non-BPSD outcomes (most ≤26 weeks) and 12 reporting BPSD (most ≤12 weeks) were analyzed. Across CATD severity, mostly low-strength evidence suggested that, compared with placebo, cholinesterase inhibitors produced small average improvements in cognition (median standardized mean difference [SMD], 0.30 [range, 0.24 to 0.52]), no difference to small improvement in function (median SMD, 0.19 [range, -0.10 to 0.22]), no difference in the likelihood of at least moderate improvement in global clinical impression (median absolute risk difference, 4% [range, 2% to 4%]), and increased withdrawals due to adverse events. In adults with moderate to severe CATD receiving cholinesterase inhibitors, low- to insufficient-strength evidence suggested that, compared with placebo, add-on memantine inconsistently improved cognition and improved global clinical impression but not function. Evidence was mostly insufficient about prescription drugs for BPSD and about supplements for all outcomes. LIMITATION Most drugs had few trials without high ROB, especially for supplements, active drug comparisons, BPSD, and longer trials. CONCLUSION Cholinesterase inhibitors and memantine slightly reduced short-term cognitive decline, and cholinesterase inhibitors slightly reduced reported functional decline, but differences versus placebo were of uncertain clinical importance. Evidence was mostly insufficient on drug treatment of BPSD and on supplements for all outcomes. PRIMARY FUNDING SOURCE Agency for Healthcare Research and Quality. (PROSPERO CRD42018117897).
-
7.
Adjunctive Raloxifene and Isradipine Improve Cognitive Functioning in Patients With Schizophrenia: A Pilot Study.
Vahdani, B, Armani Kian, A, Esmaeilzadeh, A, Zenoozian, S, Yousefi, V, Mazloomzadeh, S
Journal of clinical psychopharmacology. 2020;(5):457-463
Abstract
BACKGROUND Cognitive impairment is the most important feature of schizophrenia leading to severe functional disability. To identify pathways that improve pathophysiological neurocognition in schizophrenia is a current challenge for the development of goal-directed clinical interventions. In the present study, we investigated the effects of raloxifene (a selective estrogen modulator) and isradipine (a voltage-gated L-type calcium channel blocker) on cognitive deficits in patients with schizophrenia. METHOD We designed a double-blind, randomized, parallel, placebo-controlled trial. We randomized 60 patients with schizophrenia into 3 groups including isradipine 5 mg, raloxifine 60 mg, and placebo for 6 consequent weeks, all in the same shape capsules, 2 times a day, along with treatment as usual. The initial and final results of blood tests, electrocardiograms, and cognitive tests in specific domains, such as attention, processing speed, executive function, and verbal memory were evaluated. RESULTS Our findings revealed a remarkable association between adjunctive raloxifene treatment and the alleviation of verbal memory deficits. Isradipine treatment significantly improved the verbal memory and attention dysfunction in some variables of the Stroop test, compared with the placebo. However, no effect was observed in processing speed and executive function deficits. CONCLUSIONS To the best of our knowledge, this study provides the first evidence that isradipine is a novel therapy option improving verbal memory and attention, both related to its activity in the hippocampus and the cerebellum. Further investigations are necessary to elucidate the mechanisms of action for both drugs in schizophrenia.
-
8.
The Effect of Long-Term Aronia melanocarpa Extract Supplementation on Cognitive Performance, Mood, and Vascular Function: A Randomized Controlled Trial in Healthy, Middle-Aged Individuals.
Ahles, S, Stevens, YR, Joris, PJ, Vauzour, D, Adam, J, de Groot, E, Plat, J
Nutrients. 2020;(8)
Abstract
Cognitive decline is associated with lifestyle-related factors such as overweight, blood pressure, and dietary composition. Studies have reported beneficial effects of dietary anthocyanins on cognition in older adults and children. However, the effect of anthocyanin-rich Aronia melanocarpa extract (AME) on cognition is unknown. Therefore, this study aimed to determine the effect of long-term supplementation with AME on cognitive performance, mood, and vascular function in healthy, middle-aged, overweight adults. In a randomized double-blind placebo-controlled parallel study, 101 participants either consumed 90 mg AME, 150 mg AME, or placebo for 24 weeks. The grooved pegboard test, number cross-out test, and Stroop test were performed as measures for psychomotor speed, attention, and cognitive flexibility. Mood was evaluated with a visual analogue scale, serum brain-derived neurotrophic factor (BDNF) was determined, and vascular function was assessed by carotid ultrasounds and blood pressure measurements. AME improved psychomotor speed compared to placebo (90 mg AME: change = -3.37; p = 0.009). Furthermore, 150 mg AME decreased brachial diastolic blood pressure compared to 90 mg AME (change = 2.44; p = 0.011), but not compared to placebo. Attention, cognitive flexibility, BDNF, and other vascular parameters were not affected. In conclusion, AME supplementation showed an indication of beneficial effects on cognitive performance and blood pressure in individuals at risk of cognitive decline.
-
9.
Effect of a Multimodal Lifestyle Intervention on Sleep and Cognitive Function in Older Adults with Probable Mild Cognitive Impairment and Poor Sleep: A Randomized Clinical Trial.
Falck, RS, Davis, JC, Best, JR, Chan, PCY, Li, LC, Wyrough, AB, Bennett, KJ, Backhouse, D, Liu-Ambrose, T
Journal of Alzheimer's disease : JAD. 2020;(1):179-193
Abstract
BACKGROUND Poor sleep is common among older adults with mild cognitive impairment (MCI) and may contribute to further cognitive decline. Whether multimodal lifestyle intervention that combines bright light therapy (BLT), physical activity (PA), and good sleep hygiene can improve sleep in older adults with MCI and poor sleep is unknown. OBJECTIVE To assess the effect of a multimodal lifestyle intervention on sleep in older adults with probable MCI and poor sleep. METHODS This was a 24-week proof-of-concept randomized trial of 96 community-dwelling older adults aged 65-85 years with probable MCI (<26/30 on the Montreal Cognitive Assessment) and poor sleep (>5 on the Pittsburgh Sleep Quality Index [PSQI]). Participants were allocated to either a multimodal lifestyle intervention (INT); or 2) education + attentional control (CON). INT participants received four once-weekly general sleep hygiene education classes, followed by 20-weeks of: 1) individually-timed BLT; and 2) individually-tailored PA promotion. Our primary outcome was sleep efficiency measured using the MotionWatch8© (MW8). Secondary outcomes were MW8-measured sleep duration, fragmentation index, wake-after-sleep-onset, latency, and PSQI-measured subjective sleep quality. RESULTS There were no significant between-group differences in MW8 measured sleep efficiency at 24-weeks (estimated mean difference [INT -CON]: 1.18%; 95% CI [-0.99, 3.34]), or any other objective-estimate of sleep. However, INT participants reported significantly better subjective sleep quality at 24-weeks (estimated mean difference: -1.39; 95% CI [-2.72, -0.06]) compared to CON. CONCLUSION Among individuals with probable MCI and poor sleep, a multimodal lifestyle intervention improves subjective sleep quality, but not objectively estimated sleep.
-
10.
A Public Health Issue: Dietary Supplements Promoted for Brain Health and Cognitive Performance.
Crawford, C, Boyd, C, Avula, B, Wang, YH, Khan, IA, Deuster, PA
Journal of alternative and complementary medicine (New York, N.Y.). 2020;(4):265-272
-
-
Free full text
-
Abstract
Background: Dietary supplements targeting brain health have quickly emerged in the marketplace as cognitive performance becomes an important public health issue. While manufacturers are required to report the exact ingredients and formulations listed on the Supplement Facts labels of products, many reports have indicated such labels are not always truthful, and the content of some products is inconsistent with the ingredients listed on the Supplement Facts label. Objectives: To identify dietary supplement products and ingredients marketed for brain health and cognitive performance and perform analyses of select products to verify whether purported claims are truthful and product labels accurate. Design: A scoping review was performed to identify products and ingredients. Products were selected for content analysis, investigated for scientific-sounding claims made, and assessed using an educational tool for potential red flags when reading Supplement Facts labels. Results: Twelve products were selected from the 650 products being marketed for brain health and queried about by Service Members. Eight (67%) had at least one ingredient listed on the Supplement Facts label not detected through analysis. Compounds not reported on the label were detected in 10 (83%) products. Scientific-sounding claims made are not supported by science and red flags are presented. Conclusions: There are dietary supplements targeting brain health being marketed to consumers that should be considered adulterated and misbranded. Advertisements and product labels may be deceiving and could put the public at risk. Education is required so that the public can recognize red flags while the U.S. Food and Drug Administration works to "modernize" the current regulations for dietary supplements.