Cognitive effects following acute wild blueberry supplementation in 7- to 10-year-old children

The effect of fruits and vegetables on children's mental and cognitive health: A systematic review of intervention studies and perspective for future research

OBJECTIVES

To synthesize evidence from fruit and vegetable intervention studies investigating mental or cognitive health outcomes (or both) in children ≤10 y. Our aim was to understand the efficacy of such interventions in improving measures of cognitive performance or mental health and to identify successful intervention elements to inform future research.

METHODS

We conducted a systematic search of the Cochrane, Embase, PubMed, and CINAHL databases for articles published before August 2022 (PROSPERO registration no. CRD42022356571). A narrative synthesis was conducted according to the Synthesis Without Meta-Analysis guidelines.

RESULTS

Of the 4686 articles identified, only 7 of the 17 full texts screened were included in the final review. No studies investigated the efficacy of interventions using "whole" fruits or vegetables. Six studies examined the effects of blueberries using drinks made from fresh (1 cup) or freeze-dried (30 g) blueberries and one study evaluated a mulberry powder-based drink. Sample sizes ranged from 14 to 54, and most studies were acute interventions with outcomes measured in a 2- to 3-h window (n = 6). Through a narrative synthesis of direction of responses, measures of executive function appeared sensitive to intervention effects in both acute and longer-term settings. Some concerns of risk of bias were evident, according to the RoB 2 tool, related to incomplete reporting of methodological aspects.

CONCLUSIONS

The studies identified through this systematic review could not directly address the planned research question, resulting in poor certainty of evidence. Future research with whole fruit and vegetable interventions could better inform population health strategies for improved mental and cognitive health outcomes in children.

Dose-dependent effects of anthocyanin-rich extracts on obesity-induced inflammation and gut microbiota modulation

Obesity and its associated inflammatory state pose a significant health burden. Anthocyanins, bioactive compounds found in fruits and vegetables, have garnered interest in their potential to attenuate these conditions. Understanding the dose-dependent response of anthocyanins is essential for optimizing their therapeutic potential in preventing and managing obesity. This comprehensive review explores the current knowledge on the dose-dependent effects of anthocyanins on obesity in both human and animal models, analyzing the structure and mechanism of absorption of these compounds. The article also highlights the diverse mechanisms underlying anthocyanin action, the symbiosis between anthocyanins and gut microbiota impacting metabolite production, influencing diverse health outcomes, modulating cytokines, and activating anti-inflammatory pathways. Additionally, their impact on energy metabolism and lipid regulation is discussed, highlighting potential contributions to weight management through AMPK and PPARγ pathways. Despite promising results, dose-dependent effects are fundamental considerations, with some studies indicating less favorable outcomes at higher doses. Future research should focus on optimizing dosages, accounting for individual responses, and translating findings into effective clinical applications for obesity management.

Nano techniques: an updated review focused on anthocyanin stability

Anthocyanins (ACNs) are one of the subgroups of flavonoids and getting intensive attraction due to the nutritional values. However, their application of ACNs is limited due to their poor stability and bioavailability. Accordingly, nanoencapsulation has been developed to enhance its stability and bio-efficacy. This review focuses on the nano-technique applications of delivery systems that be used for ACNs stabilization, with an emphasis on physicochemical stability and health benefits. ACNs incorporated with delivery systems in forms of nano-particles and fibrils can achieve advanced functions, such as improved stability, enhanced bioavailability, and controlled release. Also, the toxicological evaluation of nano delivery systems is summarized. Additionally, this review summarizes the challenges and suggests the further perspectives for the further application of ACNs delivery systems in food and medical fields.

Exploring the Potential of Anthocyanins for Repairing Photoaged Skin: A Comprehensive Review

Long-term exposure to ultraviolet (UV) rays can result in skin photoaging, which is primarily characterized by dryness, roughness, pigmentation, and a loss of elasticity. However, the clinical drugs commonly employed to treat photoaged skin often induce adverse effects on the skin. Anthocyanins (ACNs) are water-soluble pigments occurring abundantly in various flowers, fruits, vegetables, and grains and exhibiting a range of biological activities. Studies have demonstrated that ACNs contribute to the repair of photoaged skin due to their diverse biological characteristics and minimal side effects. Evidence suggests that the stability of ACNs can be enhanced through encapsulation or combination with other substances to improve their bioavailability and permeability, ultimately augmenting their efficacy in repairing photoaged skin. A growing body of research utilizing cell lines, animal models, and clinical studies has produced compelling data demonstrating that ACNs mitigate skin photoaging by reducing oxidative stress, alleviating the inflammatory response, improving collagen synthesis, alleviating DNA damage, and inhibiting pigmentation. This review introduces sources of ACNs while systematically summarizing their application forms as well as mechanisms for repairing photoaged skin. Additionally, it explores the potential role of ACNs in developing functional foods. These findings may provide valuable insight into using ACNs as promising candidates for developing functional products aimed at repairing photoaged skin.

Addressing Mental Health in Rural Settings: A Narrative Review of Blueberry Supplementation as a Natural Intervention

Depression and anxiety are major public health issues; however, there is an unmet need for novel, effective, and accessible treatments, particularly in rural communities. Blueberries are an unexplored nutraceutical for these conditions due to their excellent nutritional profile, with particularly high levels of polyphenols and anthocyanins and benefits on mood, cognition, and health. Here, we present a narrative review of the literature concerning the etiology and treatments of major depressive disorder (MDD) and generalized anxiety disorder (GAD). In both animal and human studies, blueberry supplementation can ameliorate behavioral symptoms of both anxiety and depression. The mechanistic underpinnings of these behavioral improvements are not fully defined, but likely involve biochemical alterations in the gut-brain axis, including to inflammatory cytokines, reactive oxygen species, and growth factors. We also review the limitations of traditional therapies in rural settings. Finally, we assess the potential benefit of nutraceutical interventions, particularly blueberries, as novel therapeutics for these distinct, yet related mental health issues.

Postprandial appetite responses to a pecan enriched meal: A randomized crossover trial

Longer-term pecan consumption has shown appetite-regulating effects as a part of a free-living diet, yet the physiologic appetite responses to a single pecan-containing meal are unclear. The purpose of this study was to compare the acute physiologic, subjective, and direct appetite responses of a pecan-containing meal to an energy- and macronutrient-matched control meal. This was an acute meal challenge study utilizing a double-blinded randomized crossover design with two periods. Participants were young, healthy adults (BMI: 22.9 ± 3.3 kg/m2, age: 22 ± 3 y) who consumed a meal containing either 68 g of pecans (PEC; 795 kcal) or an energy- and macronutrient-matched control meal (CON; 794 kcal) on separate testing days. At both testing visits, five postprandial blood draws, and visual analog scale (VAS) questionnaires (in-lab) were used to determine differences in peptide YY (PYY), ghrelin, and subjective appetite over a 4-h postprandial period. Participants also completed VAS questionnaires (at-home) and food records for the rest of the day after leaving the testing visits. Thirty-one out of thirty-two randomized participants completed the study. There was a greater overall postprandial PYY response (p < 0.001), and a greater suppression of postprandial ghrelin after time point 120 min (p < 0.001), with the PEC vs. CON meal. Further, there was a greater increase in subjective fullness (p = 0.001), and suppression of at-home overall appetite (p = 0.02), from time 240-780 min post-meal with PEC vs. CON meals. There were no differences in self-reported EI between meals or any other VAS measure. In conclusion, a pecan-containing breakfast shake produced more favorable physiologic and subjective improvements in appetite compared to an energy- and macronutrient-matched control meal. This trial is registered at clinicaltrials.gov (NCT05230212).

Red Bull Energy Drink Impact on Salivary Glands in Wistar Rats: Can Blueberry Extract Reverse the Damage?

Energy drink (ED) consumption has become increasingly popular. Due to a lack of evidence, it was crucial to assess the effects of Red Bull (RB) consumption on the rat submandibular salivary gland and the potential therapeutic impact of blueberry (BB). Thirty rats were randomly assigned to five groups. Group 1 (Control) received distilled water. Group 2 (RB) received RB (10 mL/100 g/day) for 8 weeks. Group 3 (BB) rats were administered BB (500 mg/day for 8 weeks). Group 4 (RB + BB (L)) received RB for 8 weeks, and from the 5th week, were concurrently given BB (250 mg/day) for 4 weeks. Group 5 (RB + BB (H)) received RB for 8 weeks, and from the 5th week, were concurrently given BB (500 mg/day) for 4 weeks. At the end of the experiment, blood samples were collected, the animals were euthanized, and their submandibular salivary glands were harvested. Oxidative stress markers (MDA, GPx, CAT, and SOD) were assessed in both serum and tissue. Inflammatory markers (TNF-α, IL-6, and IL-10) were quantified in tissue. Submandibular gland specimens were prepared for light microscopy, and immunohistochemical staining was performed using anti-α-SMA. RB consumption resulted in a significant increase in MDA, TNF-α, IL-6, and IL-10, while GPx, CAT, and SOD levels decreased significantly. Degenerative changes in the gland's structure were observed in the RB group. A significant increase in α-SMA immunoreaction was detected in myoepithelial cells. Administration of BB, particularly at a high dose, ameliorated the aforementioned findings. In conclusion, blueberry administration exhibited therapeutic effects due to its antioxidative and anti-inflammatory properties.

Short-term Aronia melanocarpa extract supplementation improves cognitive performance: a randomized, double-blind, placebo-controlled cross-over study in healthy young adults

PURPOSE

Evidence on the potential beneficial effects of anthocyanin-rich foods and supplements on cognitive performance is mainly based on acute or long-term studies in older adults. However, short-term studies focusing on a younger population are lacking. Therefore, short-term effects of Aronia melanocarpa extract (AME) supplementation on cognitive performance were investigated in healthy young adults. Potential underlying mechanisms were also addressed.

METHODS

A randomized, double-blind, placebo-controlled cross-over study was performed involving 35 apparently healthy young adults. Participants consumed AME (180 mg anthocyanins/day) or a placebo for 1 week, separated by at least 2 weeks of wash-out. Cognitive performance was assessed using the Cambridge Neuropsychological Test Automated Battery (CANTAB). Furthermore, arterial stiffness (carotid-to-femoral pulse wave velocity), retinal microvascular calibers (fundus photography), and serum brain-derived neurotrophic factor (BDNF) concentrations were measured at baseline and after 1 week.

RESULTS

Participants had a mean age of 25 ± 4 years and an average BMI of 23.4 ± 2.7 kg/m2. Compliance was excellent and the study product was well-tolerated. As compared to placebo, movement time was significantly reduced by 4.8% within the five-choice reaction time test after 1 week of AME supplementation (intervention effect: - 12 ms; p < 0.05). Memory and executive function did however not change. Serum BDNF concentrations were significantly higher after AME supplementation as compared to placebo (+ 5.7%; intervention effect: 1.8 ng/mL; p < 0.05). However, arterial stiffness and retinal microvascular calibers were not affected.

CONCLUSION

Short-term AME supplementation beneficially affected cognitive performance as attention and psychomotor speed improved. Serum BDNF concentrations were increased, but vascular function markers were not affected.

CLINICAL TRIAL REGISTRATION

The study was registered on Clinical Trials under NCT03793777 on January 4th, 2019.

Mitigating Traumatic Brain Injury: A Narrative Review of Supplementation and Dietary Protocols

Traumatic brain injuries (TBIs) constitute a significant public health issue and a major source of disability and death in the United States and worldwide. TBIs are strongly associated with high morbidity and mortality rates, resulting in a host of negative health outcomes and long-term complications and placing a heavy financial burden on healthcare systems. One promising avenue for the prevention and treatment of brain injuries is the design of TBI-specific supplementation and dietary protocols centred around nutraceuticals and biochemical compounds whose mechanisms of action have been shown to interfere with, and potentially alleviate, some of the neurophysiological processes triggered by TBI. For example, evidence suggests that creatine monohydrate and omega-3 fatty acids (DHA and EPA) help decrease inflammation, reduce neural damage and maintain adequate energy supply to the brain following injury. Similarly, melatonin supplementation may improve some of the sleep disturbances often experienced post-TBI. The scope of this narrative review is to summarise the available literature on the neuroprotective effects of selected nutrients in the context of TBI-related outcomes and provide an evidence-based overview of supplementation and dietary protocols that may be considered in individuals affected by-or at high risk for-concussion and more severe head traumas. Prophylactic and/or therapeutic compounds under investigation include creatine monohydrate, omega-3 fatty acids, BCAAs, riboflavin, choline, magnesium, berry anthocyanins, Boswellia serrata, enzogenol, N-Acetylcysteine and melatonin. Results from this analysis are also placed in the context of assessing and addressing important health-related and physiological parameters in the peri-impact period such as premorbid nutrient and metabolic health status, blood glucose regulation and thermoregulation following injury, caffeine consumption and sleep behaviours. As clinical evidence in this research field is rapidly emerging, a comprehensive approach including appropriate nutritional interventions has the potential to mitigate some of the physical, neurological, and emotional damage inflicted by TBIs, promote timely and effective recovery, and inform policymakers in the development of prevention strategies.

Inulin and Freeze-Dried Blueberry Intervention Lead to Changes in the Microbiota and Metabolites within In Vitro Studies and in Cognitive Function within a Small Pilot Trial on Healthy Children

The relationship between the gut microbiota and cognitive health is complex and bidirectional, being significantly impacted by our diet. Evidence indicates that polyphenols and inulin can impact cognitive function via various mechanisms, one of which is the gut microbiota. In this study, effects of a wild blueberry treatment (WBB) and enriched chicory inulin powder were investigated both in vitro and in vivo. Gut microbiota composition and metabolites, including neurotransmitters, were assessed upon faecal microbial fermentation of WBB and inulin in a gut model system. Secondly, microbiota changes and cognitive function were assessed in children within a small pilot (n = 13) trial comparing WBB, inulin, and a maltodextrin placebo, via a series of tests measuring executive function and memory function, with faecal sampling at baseline, 4 weeks post-intervention and after a 4 week washout period. Both WBB and inulin led to microbial changes and increases in levels of short chain fatty acids in vitro. In vivo significant improvements in executive function and memory were observed following inulin and WBB consumption as compared to placebo. Cognitive benefits were accompanied by significant increases in Faecalibacterium prausnitzii in the inulin group, while in the WBB group, Bacteroidetes significantly increased and Firmicutes significantly decreased (p < 0.05). As such, WBB and inulin both impact the microbiota and may impact cognitive function via different gut-related or other mechanisms. This study highlights the important influence of diet on cognitive function that could, in part, be mediated by the gut microbiota.

Effects of fruit and vegetable intake on memory and attention: a systematic review of randomized controlled trials

BACKGROUND

Memory and attention are important for daily functioning, and their function deteriorates due to aging. However, fruit and vegetable consumption are one of the protective factors against deterioration in memory and attention. This systematic review of randomized controlled trials (RCTs) aims to identify the effects of fruit and vegetable consumption on memory and attention.

METHODS

We conducted a systematic search in EBSCOhost, ProQuest, PubMed, Embase, and Web of Science from inception up to 06/09/2022. The inclusion criteria were peer-reviewed articles, fruit and vegetable intake measured using randomized controlled trials, and the outcome measures that showed the results of memory and attention scores. Two researchers independently extracted articles that met the selection criteria and evaluated the quality of each study.

RESULTS

There were 70 articles identified from the databases, of which 13 articles met the inclusion criteria and were included in this systematic review. There were 493 participants in total. The results show that consumption of fruit and vegetable intake improved memory and attention in longitudinal studies (10 to 12 weeks). Children showed improvement in immediate recall after supplementation with blueberries. Older adults required a higher dose of fruit and vegetable intake consumption to achieve significant improvement compared with children and younger adults. Furthermore, the effect of fruits and vegetables on memory showed better immediate memory recall than delayed recall.

CONCLUSION

This systematic review showed that there is an improvement in memory and attention with fruit and vegetable intake consumption. Hence, awareness of fruit and vegetable intake consumption is important to maintain cognitive health.

Wild Blueberry Extract Intervention in Healthy Older Adults: A Multi-Study, Randomised, Controlled Investigation of Acute Cognitive and Cardiovascular Effects

BACKGROUND

Circadian and homeostatic declines in cognitive performance are observed during the day, most commonly at 14:00. Additionally, postprandial reductions in cognitive ability have been widely demonstrated 1 h after lunch consumption, affecting domains of executive functioning (EF), episodic memory (EM), and attention. Existing evidence shows that anthocyanin-rich foods such as berries may improve or attenuate the decline in EF and EM in ageing adults. Further research is required to assess whether extracts such as wild blueberry extract (WBE) may be beneficial for cognitive function across an acute timeframe, including known periods of reduced functioning.

OBJECTIVES

(1) Study 1: ROAB: To investigate the efficacy of WBE in maintaining EF and EM throughout the day alongside measures of cardiovascular outcomes in healthy older adults. A range of WBE doses were utilised to identify the optimal dose at which cognitive and cardiovascular effects occur. (2) Study 2: BEAT: To replicate alleviation of cognitive decline during a predicted post-lunch dip whilst also improving cardiovascular outcomes following acute WBE 222 mg supplementation.

METHODS

Both studies employed a randomised, double-blind, cross-over, placebo-controlled design to explore the effects of WBE intervention versus placebo on several outcomes, including EM, EF, blood pressure, and heart rate in a healthy older adult population (aged 68-75). In ROAB, 28 participants received a single dose of WBE 111 mg, 222 mg, 444 mg, or 888 mg or placebo over a 5-week period, each separated by a 1-week washout. Outcomes were measured at 0 h, 2 h, 4 h, and 6 h post intervention, with intervention occurring immediately after baseline (0 h). In BEAT, 45 participants received WBE 222 mg and placebo (1-week washout). Outcomes were measured at 0 h and 6 h (14:00) when a post-lunch dip was anticipated. This was further enhanced by consumption of lunch 1 h prior to cognitive testing. The WBE 222 mg intervention aligned with known peaks in plasma blueberry polyphenol metabolites at 2 h post dosing, which would coincide with a predicted drop in post-lunch performance.

RESULTS

ROAB: A significant dip in executive function was apparent at the 4 h timepoint for placebo only, indicating attenuation for WBE doses. Strikingly, WBE 222 mg produced acute reductions in both systolic and diastolic blood pressure compared with placebo. BEAT: EF reaction time was found to be significantly faster for WBE 222 compared to placebo at the predicted post-lunch dip (14:00), with no other notable benefits on a range of cognitive and cardiovascular outcomes.

CONCLUSION

These two studies indicate that WBE may have cardiovascular benefits and attenuate the natural cognitive decline observed over the course of the day, particularly when a decline is associated with a circadian rhythm-driven postprandial dip. However, it is important to acknowledge that effects were subtle, and benefits were only observed on a small number of outcomes. Further research is required to explore the utility of WBE in populations already experiencing mild cognitive impairments.

Adult neurogenesis: a real hope or a delusion?

Adult neurogenesis, the process of creating new neurons, involves the coordinated division, migration, and differentiation of neural stem cells. This process is restricted to neurogenic niches located in two distinct areas of the brain: the subgranular zone of the dentate gyrus of the hippocampus and the subventricular zone of the lateral ventricle, where new neurons are generated and then migrate to the olfactory bulb. Neurogenesis has been thought to occur only during the embryonic and early postnatal stages and to decline with age due to a continuous depletion of neural stem cells. Interestingly, recent years have seen tremendous progress in our understanding of adult brain neurogenesis, bridging the knowledge gap between embryonic and adult neurogenesis. Here, we discuss the current status of adult brain neurogenesis in light of what we know about neural stem cells. In this notion, we talk about the importance of intracellular signaling molecules in mobilizing endogenous neural stem cell proliferation. Based on the current understanding, we can declare that these molecules play a role in targeting neurogenesis in the mature brain. However, to achieve this goal, we need to avoid the undesired proliferation of neural stem cells by controlling the necessary checkpoints, which can lead to tumorigenesis and prove to be a curse instead of a blessing or hope.

Comprehensive Extraction and Chemical Characterization of Bioactive Compounds in Tepals of Crocus sativus L

Crocus sativus L. is largely cultivated because it is the source of saffron, a well-appreciated and valued spice, not only for its culinary use but also because of its significant biological activities. Stigmas are the main product obtained from flowers, but in addition, tepals, largely considered a waste product, represent a big source of flavonoids and anthocyanins. This study aimed to delve into the phytochemical composition of saffron tepals and investigate whether the composition was influenced by the extraction technique while investigating the main analytical techniques most suitable for the characterization of tepal extracts. The research focuses on flavonoids, a class of secondary metabolites, and their health benefits, including antioxidant, anti-inflammatory, and anticancer properties. Flavonoids occur as aglycones and glycosides and are classified into various classes, such as flavones, flavonols, and flavanones. The most abundant flavonoids in tepals are kaempferol glycosides, followed by quercetin and isorhamnetin glycosides. Overall, this review provides valuable insights into the potential uses of tepals as a source of bioactive compounds and their applications in various fields, promoting a circular and sustainable economy in saffron cultivation and processing.

Dietary Flavonoids and Human Cognition: A Meta-Analysis

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

Association between dietary quality and executive functions in school-aged children with autism spectrum disorder

Background

It is well known that children with autism spectrum disorder (ASD) had executive functions deficit. However, it is still unclear whether the poor dietary quality is related to the impairment of executive functions. The current study aimed to explore the association between dietary quality and executive functions in children with ASD.

Methods

A total of 106 children with ASD (7.7 ± 1.3 years) and 207 typically developing (TD) children (7.8 ± 1.3 years) were enrolled from Guangzhou, China. The Chinese version of Behavior Rating Scale of Executive function (BRIEF), the working memory subscales of the Chinese version of Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV), and the Stroop Color-Word Test (SCWT) were used to measure the participant's executive functions. The food frequency questionnaire (FFQ) was used to collect the dietary intake information, and the Chinese Diet Balance Index (DBI_16) was used to evaluate the dietary quality. Generalized linear models were used to estimate the association between dietary quality and executive functions.

Results

In children with ASD, Low Bound Score (LBS) was positively correlated with the working memory subscale score of BRIEF (β = 0.23, 95% CI: 0.02–0.44, P < 0.05), while High Bound Score (HBS) and LBS were positively correlated with the organizable subscale score of BRIEF (β = 0.44, 95% CI: 0.11–0.77, P < 0.01; β = 0.19, 95% CI: 0.01–0.37, P < 0.05). Compared to TD children, children with ASD had a higher proportion of moderate and high levels of insufficient dietary intake (moderate level, 37.7% vs. 23.2%, high level, 4.7% vs. 1.4%) and moderate level of unbalanced dietary intake (36.8% vs.21.3%), higher scores on all subscales of BRIEF (P < 0.01), and lower score on the working memory (81.3 ± 32.3 vs. 104.6 ± 12.5, P < 0.01), while there was no difference on the SCWT.

Conclusion

Poor dietary quality was associated with the impairment of working memory and organizational capacity in children with ASD. This study emphasized the importance of dietary quality in executive functions among children with ASD, and attention should be paid to improving their dietary quality.

Anthocyanins as Key Phytochemicals Acting for the Prevention of Metabolic Diseases: An Overview

Anthocyanins are water-soluble pigments present in fruits and vegetables, which render them an extensive range of colors. They have a wide distribution in the human diet, are innocuous, and, based on numerous studies, have supposed preventive and therapeutical benefits against chronic affections such as inflammatory, neurological, cardiovascular, digestive disorders, diabetes, and cancer, mostly due to their antioxidant action. Despite their great potential as pharmaceutical applications, they have a rather limited use because of their rather low stability to environmental variations. Their absorption was noticed to occur best in the stomach and small intestine, but the pH fluctuation of the digestive system impacts their rapid degradation. Urine excretion and tissue distribution also occur at low rates. The aim of this review is to highlight the chemical characteristics of anthocyanins and emphasize their weaknesses regarding bioavailability. It also targets to deliver an update on the recent advances in the involvement of anthocyanins in different pathologies with a focus on in vivo, in vitro, animal, and human clinical trials.

Anthocyanins: Traditional Uses, Structural and Functional Variations, Approaches to Increase Yields and Products' Quality, Hepatoprotection, Liver Longevity, and Commercial Products

Anthocyanins are water-soluble, colored compounds of the flavonoid class, abundantly found in the fruits, leaves, roots, and other parts of the plants. The fruit berries are prime sources and exhibit different colors. The anthocyanins utility as traditional medicament for liver protection and cure, and importance as strongest plants-based anti-oxidants have conferred these plants products different biological activities. These activities include anti-inflammation, liver protective, analgesic, and anti-cancers, which have provided the anthocyanins an immense commercial value, and has impelled their chemistry, biological activity, isolation, and quality investigations as prime focus. Methods in extraction and production of anthocyanin-based products have assumed vital economic importance. Different extraction techniques in aquatic solvents mixtures, eutectic solvents, and other chemically reactive extractions including low acid concentrations-based extractions have been developed. The prophylactic and curative therapy roles of the anthocyanins, together with no reported toxicity has offered much-needed impetus and economic benefits to these classes of compounds which are commercially available. Information retrieval from various search engines, including the PubMed®, ScienceDirect®, Scopus®, and Google Scholar®, were used in the review preparation. This imparted an outlook on the anthocyanins occurrence, roles in plants, isolation-extraction, structures, biosynthetic as well as semi- and total-synthetic pathways, product quality and yields enhancements, including uses as part of traditional medicines, and uses in liver disorders, prophylactic and therapeutic applications in liver protection and longevity, liver cancer and hepatocellular carcinoma. The review also highlights the integrated approach to yields maximizations to meet the regular demands of the anthocyanins products, also as part of the extract-rich preparations together with a listing of marketed products available for human consumption as nutraceuticals/food supplements.

Effects of Berry Anthocyanins on Cognitive Performance, Vascular Function and Cardiometabolic Risk Markers: A Systematic Review of Randomized Placebo-Controlled Intervention Studies in Humans

Supplementation with anthocyanins, which are a type of flavonoids mainly found in various berries, is hypothesized to be a promising approach to lower the risk of developing cognitive decline. The aim of this systematic review was to provide a comprehensive overview of dietary intervention trials describing effects of berry anthocyanins on cognitive performance in humans, while also addressing potential underlying mechanisms. A total of 1197 articles were identified through a systematic search, and 49 studies reporting effects on cognitive performance (n = 18), vascular function (n = 22), or cardiometabolic risk markers (n = 32) were included. Significant improvements were observed on memory, while some of the studies also reported effects on attention and psychomotor speed or executive function. Vascular function markers such as brachial artery flow-mediated vasodilation were also affected and consistent evidence was provided for the beneficial effects of berry anthocyanins on endothelial function. Finally, studies reported improvements in blood pressure, but effects on metabolic risk markers (e.g. carbohydrate and lipid metabolism) were less consistent. In conclusion, this review provides evidence for the beneficial effects of berry anthocyanins on cognitive performance as memory improved. Whether observed anthocyanin-induced improvements in vascular function and blood pressure underlie beneficial effects on cognitive performance warrants further study.

Qualitative and quantitative analysis of phenolic compounds in blueberries and protective effects on hydrogen peroxide-induced cell injury

This work was conducted to optimize an accelerated solvent extraction for ultra high performance liquid chromatography-mass spectrometry/mass spectrometry analysis of blueberry phenolic compounds. The conditions for accelerated solvent extraction were verified using response surface methodology to obtain the following optimized conditions: ethanol concentration (pH = 3), 48%; temperature, 50℃, and static cycle times, 3. Further, ultra high performance liquid chromatography with quadrupole Exactive Orbitrap mass spectrometry and ultra high performance liquid chromatography with triple-quadrupole tandem mass methods for determination of the detailed phenolic composition were developed and validated. Total of 81 phenolic compounds were identified by ultra high performance liquid chromatography with quadrupole Exactive Orbitrap mass spectrometry including 23 anthocyanins, 32 flavonols, 11 proanthocyanidins, 2 other flavonoids, and 13 phenolic acids. Fifty-one of these compounds have been simultaneously quantified by ultra high performance liquid chromatography with triple-quadrupole tandem mass including 31 anthocyanins, 8 flavonols, 6 proanthocyanidins, 2 other flavonoids, and 8 phenolic acids. Malvidin-dinhexoside has, for the first time, been detected in wild. Moreover, by verifying the protection on PC12 cells against oxidative damage, it was showed that the phenolic extracts (500 µg/mL) can improve significantly the viability (9.26-24.78%) of hydrogen peroxide-induced PC12 cells, activities of superoxide dismutase (34.59-37.90 U/mg) and glutathione peroxidase (6.87-14.42 mU/mg) and decrease the content of malonic dialdehyde (13.27-24.62 nmol/mg). Correlation analysis suggested that anthocyanins might contribute most to these activities.

Effects of daily consumption of wild blueberry on cognition and urinary metabolites in school-aged children: a pilot study

Purpose

Acute intervention with wild blueberry (WBB) has previously revealed positive cognitive and mood effects in typically developing children; however, it is unclear whether effects persist after daily supplementation. In addition, no data have been published exploring the metabolite profiles of children following berry consumption, to our knowledge. A study of this kind could provide insight into a mechanism of action for the cognitive and mood improvements observed previously in children. The aim of this pilot study was to assess cognitive performance and urinary metabolite concentrations in healthy 7–10-year-old children across a 4 week daily WBB drink intervention.

Methods

This pilot study examined the effects of daily WBB consumption for 4 weeks (766 mg total polyphenols; 253 mg anthocyanins; equivalent to 240 g fresh blueberries per day) on cognition and mood in 15 healthy 7–10-year-old children. Polyphenol metabolites were measured in 24 h urine before and after the 4 week intervention.

Results

Chronic WBB-related benefits were seen on cognitively demanding trials on the modified attention network task, a task measuring executive functioning. Specifically, the WBB group maintained significantly higher accuracy on incongruent trials (96%; SE 0.03) compared with placebo participants (85%; SE 0.03; p = 0.038) after the 4 week intervention, suggesting WBB was of most benefit on the more difficult aspects of the task. No significant WBB-related effects were observed on the auditory verbal learning task or the child’s version of the positive and negative affect schedule. Urinary metabolite analyses indicated significant increases in different metabolites in WBB and placebo groups after 4 week consumption.

Conclusion

The research demonstrates 24 h WBB bioavailability in a child cohort for the first time with increases in urinary hippuric acid excretion during 2 week daily WBB consumption. This study highlights the importance of conducting a larger study in children investigating the mechanism of action behind cognitive effects using bioavailability data.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00394-021-02588-y.

Improved metabolic function and cognitive performance in middle-aged adults following a single dose of wild blueberry

PURPOSE

Research has demonstrated cognitive benefits following acute polyphenol-rich berry consumption in children and young adults. Berry intake also has been associated with metabolic benefits. No study has yet examined cognitive performance in middle-aged adults. We investigated the relationships among cognitive and metabolic outcomes in middle-aged adults following wild blueberry (WBB) consumption.

METHODS

Thirty-five individuals aged 40-65 years participated in a randomized, double blind, cross-over study. Participants consumed a breakfast meal and 1-cup equivalent WBB drink or matched placebo beverage on two occasions. Participants completed cognitive tasks and had blood drawn before and at regular intervals for 8 h after each meal/treatment. Changes in episodic memory and executive function (EF) were assessed alongside plasma levels of glucose, insulin, and triglyceride.

RESULTS

Analysis of the memory-related Auditory Verbal Learning Task (AVLT) word recognition measure revealed a decrease in performance over the test day after placebo intake, whereas performance after WBB was maintained. For the AVLT word rejection measure, participants identified more foils following WBB in comparison to placebo. Benefits were also observed for EF on the Go/No-Go task with fewer errors following WBB intake on cognitively demanding invalid No-Go trials in comparison to placebo. Furthermore, in comparison to placebo, response times were faster for the Go/No-Go task, specifically at 4 h and 8 h following WBB treatment. We also observed reduced post-meal glucose and insulin, but not triglyceride, concentrations in comparison to placebo over the first 2 h following ingestion. Though the addition of Age, BMI, glucose and insulin as covariates to the analysis reduced the significant effect of beverage for AVLT word rejection, metabolic outcomes did not interact with treatment to predict cognitive performance with the exception of one isolated trend.

CONCLUSIONS

This study indicated acute cognitive benefits of WBB intake in cognitively healthy middle-aged individuals, particularly in the context of demanding tasks and cognitive fatigue. WBB improved glucose and insulin responses to a meal. Further research is required to elucidate the underlying mechanism by which WBB improves cognitive function.

Health benefits of cyanidin-3-glucoside as a potent modulator of Nrf2-mediated oxidative stress

Berries are natural sources of anthocyanins, especially cyanidin-3-glucoside (C3G), and exhibit significant antioxidant, antidiabetic, anti-inflammatory, and cytoprotective effects against various oxidative stress-induced disorders. C3G and its metabolites possess higher absorption and bioavailability, and interaction with gut microbiota may enhance their health benefits. Various in vitro studies have shown the reactive oxygen species (ROS)-mitigating potential of C3G. However, in in vivo models, C3G exerts its cytoprotective properties by regulating the nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant-responsive element (ARE) pathway. Despite existing reports stating various health benefits of C3G, its antioxidant potential by modulating the Nrf2 pathway remains less identified. This review discusses the Nrf2-mediated antioxidant response of C3G in modulating oxidative stress against DNA damage, apoptosis, carcinogen toxicity, and inflammatory conditions. Furthermore, we have reviewed the recent clinical trial data to establish cross talk between a berry-rich diet and disease prevention.

Blueberry Supplementation in Neuronal Health and Protective Technologies for Efficient Delivery of Blueberry Anthocyanins

Blueberries are consumed as healthy fruits that provide a variety of benefits to the nervous system. Scientists have found that blueberries can be used as a daily edible source for supplementation to prevent and minimize complexities of age-related diseases as well as to improve learning and memory in children. Anthocyanins are the most mentioned compounds among the components in blueberries, as they play a major role in providing the health benefits of this fruit. However, while they are highly active in impeding biological impairment in neuronal functions, they have poor bioavailability. This review focuses on neurological investigations of blueberries from in vitro cell studies to in vivo studies, including animal and human studies, with respect to their positive outcomes of neuroprotection and intervention in neurodegenerative conditions. Readers will also find information on the bioavailability of anthocyanins and the considerable factors affecting them so that they can make informed decisions regarding the daily consumption of blueberries. In this context, the ways in which blueberries or blueberry supplementation forms are consumed and which of these forms is best for maximizing the health benefits of blueberries should be considered important decision-making factors in the consumption of blueberries; all of these aspects are covered in this review. Finally, we discuss recent technologies that have been employed to improve the bioavailability of blueberry anthocyanins in the development of effective delivery vehicles supporting brain health.

Protective effects of grape seed procyanidin on isoflurane-induced cognitive impairment in mice

Context: Oxidative imbalance-induced cognitive impairment is among the most urgent clinical concerns. Isoflurane has been demonstrated to impair cognitive function via an increase in oxidative stress. GSP has strong antioxidant capacities, suggesting potential cognitive benefits.Objective: This study investigates whether GSP pre-treatment can alleviate isoflurane-induced cognitive dysfunction in mice.Materials and methods: C57BL/6J mice were pre-treated with either GSP 25-100 mg/kg/d for seven days or GSP 100-400 mg/kg as a single dose before the 6 h isoflurane anaesthesia. Cognitive functioning was examined using the fear conditioning tests. The levels of SOD, p-NR2B and p-CREB in the hippocampus were also analysed.Results: Pre-treatment with either a dose of GSP 50 mg/kg/d for seven days or a single dose of GSP 200 mg/kg significantly increased the % freezing time in contextual tests on the 1st (72.18 ± 12.39% vs. 37.60 ± 8.93%; 78.27 ± 8.46% vs. 52.72 ± 2.64%), 3rd (93.80 ± 7.62% vs. 52.94 ± 14.10%; 87.65 ± 10.86% vs. 52.89 ± 1.73%) and 7th (91.36 ± 5.31% vs. 64.09 ± 14.46%; 93.78 ± 3.92% vs. 79.17 ± 1.79%) day after anaesthesia. In the hippocampus of mice exposed to isoflurane, GSP 200 mg/kg increased the total SOD activity on the 1st and 3rd day and reversed the decreased activity of the NR2B/CREB pathway.Discussion and conclusions: These findings suggest that GSP improves isoflurane-induced cognitive dysfunction by protecting against perturbing antioxidant enzyme activities and NR2B/CREB pathway. Therefore, GSP may possess a potential prophylactic role in isoflurane-induced and other oxidative stress-related cognitive decline.

Blueberry benefits to cognitive function across the lifespan

It is well known that what we eat can influence our physical wellbeing, but interest is also increasing in the relationship between our diet and cognitive health. In recent years, blueberries have risen from relative obscurity to superfood status following a number of published epidemiological studies, rodent trials, and human RCTs, that suggest blueberries may convey benefits to cognition and mood. This commentary explores some of the evidence in humans, particularly during periods of cognitive development in the young and cognitive decline in the elderly. Evidence for possible mechanisms of action are also described. There is little doubt that blueberries convey a small, but tangible, benefit to cognitive function. Effects are seen following dose sizes easily achievable within a normal diet. Nevertheless, further research is needed on the cognitive domains influenced, additional benefits of longer-term supplementation, mechanisms of action responsible, and the real-world relevance of the cognitive benefits attained.

Anthocyanins: A Comprehensive Review of Their Chemical Properties and Health Effects on Cardiovascular and Neurodegenerative Diseases

Anthocyanins are a class of water-soluble flavonoids widely present in fruits and vegetables. Dietary sources of anthocyanins include red and purple berries, grapes, apples, plums, cabbage, or foods containing high levels of natural colorants. Cyanidin, delphinidin, malvidin, peonidin, petunidin, and pelargonidin are the six common anthocyanidins. Following consumption, anthocyanin, absorption occurs along the gastrointestinal tract, the distal lower bowel being the place where most of the absorption and metabolism occurs. In the intestine, anthocyanins first undergo extensive microbial catabolism followed by absorption and human phase II metabolism. This produces hybrid microbial-human metabolites which are absorbed and subsequently increase the bioavailability of anthocyanins. Health benefits of anthocyanins have been widely described, especially in the prevention of diseases associated with oxidative stress, such as cardiovascular and neurodegenerative diseases. Furthermore, recent evidence suggests that health-promoting effects attributed to anthocyanins may also be related to modulation of gut microbiota. In this paper we attempt to provide a comprehensive view of the state-of-the-art literature on anthocyanins, summarizing recent findings on their chemistry, biosynthesis, nutritional value and on their effects on human health.

Potential health benefits of (poly)phenols derived from fruit and 100% fruit juice

(Poly)phenol-rich diets have been associated with reduced risk of various diseases. Coffee and tea are typically identified as dietary sources of chlorogenic acid and flavan-3-ols; however, 100% fruit juice greatly contributes to anthocyanin, flavonol, flavan-3-ols, and flavanone intake, making them complementary sources of dietary (poly)phenols. Thus, the aim of this narrative review was to provide an overview of fruit (poly)phenols and their potential health benefits. Fruit (poly)phenols have been associated with several health benefits (eg, reduced risk of cardiovascular disease and neurocognitive benefits). Although perspectives on 100% fruit juice consumption are controversial due to the perception of sugar content, growing evidence supports the role of fruit in whole and 100% juice forms to provide consumer benefits in alignment with dietary guidance. However, differences in (poly)phenol profiles and bioavailability likely exist between whole fruit and 100% fruit juice due to processing and the presence/absence of fiber. Ongoing studies are better defining similarities and differences between whole fruit and 100% fruit juice to elucidate protective mechanisms and align with processing and consumer products.

Effect of Single Administration of Mulberry Milk on the Cognitive Function of 6-12-Year-Old Children: Results from a Randomized, Placebo-Controlled, Crossover Study

Currently, cognitive enhancers are considered necessary because they play a critical role in daily and social behaviors. The cognitive-enhancing effect of mulberry milk has gained attention due to the cognitive-enhancing effect of this anthocyanin-rich substance and the cognitive-enhancing effect of mulberry fruit in animal models. However, the effect of anthocyanin-rich mulberry milk in clinical trials especially in children is still unknown. This study was a randomized double-blind crossover intervention. A total of forty-six healthy, normal, cognitive subjects aged 6–12 years old were provided mulberry milk (containing mulberry 10 g) or placebo milk (50 mL). Attention and cognitive function were assessed using the auditory odd ball paradigm of event-related potential, whereas working memory was assessed using a computerized battery test. The assessment was performed at baseline and then at 1.5 and 3 hours postdosing. At the end of study period, the activities of acetylcholinesterase (AChE) and monoamine oxidase (MAO) together with that of saliva cortisol were determined. Following mulberry milk intervention, the decreased N100 latency and the increased P300 amplitude were increased both at 1.5 and 3 hours after dosing. The decreased response time of digit updating was observed both at 1.5 and 3 hours after dosing, whereas the decreased response time of picture updating was observed at 3 hours after dosing. In addition, the reduction of saliva cortisol was also observed at both periods. The improvement of attention and cognitive processing capabilities together with the working memory suggests the cognitive-enhancing potential of mulberry milk for school-age children. The possible underlying mechanism may be associated partly with the reduction of cortisol, a stress hormone.

Long-term dietary flavonoid intake and change in cognitive function in the Framingham Offspring cohort

OBJECTIVE

To examine the association between long-term intake of total and the six classes of dietary flavonoids and decline in cognitive function over a follow-up period of up to 15 years.

DESIGN

In this longitudinal study, we evaluated change in eight cognitive domain scores (verbal and visual memory, verbal learning, attention and concentration, abstract reasoning, language, visuoperceptual organisation and the global function) based on three neuropsychological exams and characterised the annualised change between consecutive exams. Long-term intakes of total and six flavonoid classes were assessed up to four times by a validated FFQ. Repeated-measures regression models were used to examine the longitudinal association between total and six flavonoid classes and annualised change in the eight cognitive domains.

SETTING

The Framingham Heart Study (FHS), a prospective cohort study.

PARTICIPANTS

One thousand seven hundred and seventy-nine subjects who were free of dementia, aged ≥45 years and had attended at least two of the last three FHS Offspring cohort study exams.

RESULTS

Over a median follow-up of 11·8 years with 1779 participants, nominally significant trends towards a slower decline in cognitive function were observed among those with higher flavanol and flavon-3-ol intakes for global function, verbal and visual memory; higher total flavonoids and flavonoid polymers for visual memory; and higher flavanols for verbal learning.

CONCLUSIONS

In spite of modest nominal trends, overall, our findings do not support a clear association between higher long-term flavonoid intake and slowing age-related cognitive decline.

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

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

Systematic Review of the Effects of Blueberry on Cognitive Performance as We Age

The effect of flavonoid-rich food, such as blueberries, on cognitive function has been subject to a growing amount of research interest in recent years. Epidemiological, prospective, preclinical, and clinical trials have revealed positive cognitive benefits from flavonoid interventions, particularly in relation to the amelioration of cognitive decline in older adults. This review will specifically consider the existing clinical research from both acute and chronic blueberry interventions on cognition in human subjects. The results of 11 studies are reported with 4 studies considering blueberry intervention with children aged 7-10 years, 4 considering adults aged 60 years and older, and 3 considering adults suffering from mild cognitive impairment (MCI). Findings from these studies indicate that cognitive benefits may be found for delayed memory and executive function in children and for delayed memory, executive function, and psychomotor function in older healthy and MCI adults. There is less evidence to suggest positive benefits of blueberry intervention on working memory. Recommendations for future research, including dose used, cognitive tasks, and age groups considered, are proposed.

The effects of blueberry and strawberry serum metabolites on age-related oxidative and inflammatory signaling in vitro

Berry fruits contain a variety of bioactive polyphenolic compounds that exhibit potent antioxidant and anti-inflammatory activities. We have shown that consumption of freeze-dried whole berry powder, equivalent to 1 cup per day of blueberry (BB) or 2 cups per day of strawberry (SB), can differentially improve some aspects of cognition in healthy, older adults, compared to placebo-supplemented controls. We investigated whether fasting and postprandial serum from BB- or SB-supplemented older adults (60-75 years), taken at baseline or after 45 or 90 days of supplementation, would reduce the production of inflammatory and oxidative stress markers compared to serum from a placebo group, in LPS-stressed HAPI rat microglial cells, in vitro. Serum from both BB- and SB-supplemented participants reduced nitrite production, iNOS and COX-2 expression, and TNF-alpha release relative to serum from placebo controls (p < 0.05). Protection was greatest with serum from the 90-day time-point, suggesting that ongoing supplementation may provide the most health benefits. Serum was protective in both fasted and postprandial conditions, indicating that the effects are not only acute and that the meal did not challenge subjects' ability to regulate oxidative and inflammatory stress. These results suggest that berry metabolites, present in the circulating blood following ingestion, may be mediating the anti-inflammatory effects of dietary berry fruit.

The Colors of Health: Chemistry, Bioactivity, and Market Demand for Colorful Foods and Natural Food Sources of Colorants

There is an increasing consumer demand for natural colors in foods. However, there is a limited number of available natural food sources for use by the food industry because of technical and regulatory limitations. Natural colors are less stable and have less vibrant hues compared to their synthetic color counterparts. Natural pigments also have known health benefits that are seldom leveraged by the food industry. Betalains, carotenoids, phycocyanins, and anthocyanins are major food colorants used in the food industry that have documented biological effects, particularly in the prevention and management of chronic diseases such as diabetes, obesity, and cardiovascular disease. The color industry needs new sources of stable, functional, and safe natural food colorants. New opportunities include sourcing new colors from microbial sources and via the use of genetic biotechnology. In all cases, there is an imperative need for toxicological evaluation to pave the way for their regulatory approval.

Recent Research on the Health Benefits of Blueberries and Their Anthocyanins

Awareness of the human health benefits of blueberries is underpinned by a growing body of positive scientific evidence from human observational and clinical research, plus mechanistic research using animal and in vitro models. Blueberries contain a large number of phytochemicals, including abundant anthocyanin pigments. Of their various phytochemicals, anthocyanins probably make the greatest impact on blueberry health functionality. Epidemiological studies associate regular, moderate intake of blueberries and/or anthocyanins with reduced risk of cardiovascular disease, death, and type 2 diabetes, and with improved weight maintenance and neuroprotection. These findings are supported by biomarker-based evidence from human clinical studies. Among the more important healthful aspects of blueberries are their anti-inflammatory and antioxidant actions and their beneficial effects on vascular and glucoregulatory function. Blueberry phytochemicals may affect gastrointestinal microflora and contribute to host health. These aspects have implications in degenerative diseases and conditions as well as the aging process. More evidence, and particularly human clinical evidence, is needed to better understand the potential for anthocyanin-rich blueberries to benefit public health. However, it is widely agreed that the regular consumption of tasty, ripe blueberries can be unconditionally recommended.

The effect of blueberry interventions on cognitive performance and mood: A systematic review of randomized controlled trials

Blueberries are rich in polyphenols that may be beneficial to cognitive performance and mood. The aim of this systematic review was to evaluate randomized controlled trials investigating the effects of blueberries and blueberry products on measures of cognition and mood. In total, eleven articles (that included 12 studies) were identified using freeze-dried blueberries (n = 9 studies), whole blueberries (n = 2) and blueberry concentrate (n = 1). These studies were conducted in children (n = 5), young adults (n = 1), and older people with either no known cognitive impairment (n = 4) or indicated cognitive impairment (n = 2). Eight studies reported blueberry consumption or supplementation at various doses and time lengths to improve measures of cognitive performance, particularly short- and long-term memory and spatial memory. For mood, one study reported significant between-group improvements in positive affect from blueberry products, whereas four studies reported no improvement. Low risk of bias were observed across all studies. Based on the current evidence, blueberries may improve some measures of cognitive performance. However, considerable differences in study design, dosages, and anthocyanin content hinder between-study comparison. The use of standardized blueberry interventions, consideration of placebo formulations, and consistently reported cognitive performance tools are recommended in future trials. PROSPERO registration no. CRD42018100888.

Fruits

Fruits come in a wide variety of colors, shapes, and flavors. This chapter will cover selected fruits that are known to be healthy and highly nutritious. These fruits were chosen due to their common usage and availability. Since it is not possible to cover all health benefits or essential nutrients and important phytochemicals of the fruit composition, this chapter will focus on the key valuable constituents and their potential health effects.

Cognitive impairments in type 2 diabetes, risk factors and preventive strategies

Mild cognitive impairment (MCI) is a modifiable risk factor in progression of several diseases including dementia and type 2 diabetes. If cognitive impairments are not reversed at an early stage of appearance of symptoms, then the prolonged pathogenesis can lead to dementia and Alzheimer's disease (AD). Therefore, it is necessary to detect the risk factors and mechanism of prevention of cognitive dysfunction at an early stage of disease. Poor lifestyle, age, hyperglycemia, hypercholesterolemia, and inflammation are some of the major risk factors that contribute to cognitive and memory impairments in diabetic patients. Mild cognitive impairment was seen in those individuals of type 2 diabetes, who are on an unhealthy diet. Physical inactivity, frequent alcohol consumptions, and use of packed food products that provides an excess of cheap calories are found associated with cognitive impairment and depression in diabetic patients. Omega fatty acids (FAs) and polyphenol-rich foods, especially flavonoids, can reduce the bad effects of an unhealthy lifestyle; therefore, the consumption of omega FAs and flavonoids may be beneficial in maintaining normal cognitive function. These functional foods may improve cognitive functions by targeting many enzymes and molecules in cells chiefly through their anti-inflammatory, antioxidant, or signaling actions. Here, we provide the current concepts on the risk factors of cognitive impairments in type 2 diabetes and the mechanism of prevention, using omega FAs and bioactive compounds obtained from fruits and vegetables. The knowledge derived from such studies may assist physicians in managing the health care of patients with cognitive difficulties.

Acute Intake of a Grape and Blueberry Polyphenol-Rich Extract Ameliorates Cognitive Performance in Healthy Young Adults During a Sustained Cognitive Effort

Despite an increasing level of evidence supporting the individual beneficial effect of polyphenols on cognitive performance, information related to the potential synergistic action of these phytonutrients on cognitive performance during a prolonged cognitive effort is currently lacking. This study investigated the acute and sustained action of a polyphenols-rich extract from grape and blueberry (PEGB), on working memory and attention in healthy students during a prolonged and intensive cognitive effort. In this randomised, cross-over, double blind study, 30 healthy students consumed 600 mg of PEGB or a placebo. Ninety minutes after product intake, cognitive functions were assessed for one hour using a cognitive demand battery including serial subtraction tasks, a rapid visual information processing (RVIP) task and a visual analogical scale. Flow-mediated dilation (FMD) and plasma flavan-3-ols metabolites quantification were also performed. A 2.5-fold increase in serial three subtraction variation net scores was observed following PEGB consumption versus placebo (p < 0.001). A trend towards significance was also observed with RVIP percentage of correct answers (p = 0.058). No treatment effect was observed on FMD. Our findings suggest that consumption of PEGB coupled with a healthy lifestyle may be a safe alternative to acutely improve working memory and attention during a sustained cognitive effort.

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

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

Blueberries Improve Neuroinflammation and Cognition differentially Depending on Individual Cognitive baseline Status

Daily supplementation of blueberries (BBs) reverses age-related deficits in behavior in aged rats. However, it is unknown whether BB is more beneficial to one subset of the population dependent on baseline cognitive performance and inflammatory status. To examine the effect of individual differences on the efficacy of BB, aged rats (17 months old) were assessed for cognition in the radial arm water maze (RAWM) and divided into good, average, and poor performers based on navigation errors. Half of the rats in each cognitive group were then fed a control or a 2% BB diet for 8 weeks before retesting. Serum samples were collected, pre-diet and post-diet, to assess inflammation. Latency in the radial arm water maze was significantly reduced in the BB-fed poor performers (p < .05) and preserved in the BB-fed good performers. The control-fed good performers committed more working and reference memory errors in the post-test than pretest (p < .05), whereas the BB-fed good performers showed no change. An in vitro study using the serum showed that BB supplementation attenuated lipopolysaccharide (LPS)-induced nitrite and tumor necrosis factor-alpha, and cognitive performance was associated with innate anti-inflammatory capability. Therefore, consumption of BB may reverse some age-related deficits in cognition, as well as preserve function among those with intact cognitive ability.

A Review of the Science of Colorful, Plant-Based Food and Practical Strategies for "Eating the Rainbow"

Over the past decades, thousands of published studies have amassed supporting recommendations to consume fruits and vegetables for physiological and psychological health. Newer research has emerged to suggest that these plant-based foods contain a plethora of not only vitamins and minerals, but perhaps, most importantly, phytonutrients. These phytonutrients have known pleiotropic effects on cellular structure and function, ultimately resulting in the modulation of protein kinases and subsequent epigenetic modification in a manner that leads to improved outcomes. Even though eating fruits and vegetables is a well-known feature of a healthy dietary pattern, population intakes continue to be below federal recommendations. To encourage consumers to include fruits and vegetables into their diet, an “eat by color” approach is proposed in this review. Although each individual food may have numerous effects based on its constituents, the goal of this simplified approach was to identify general patterns of benefits based on the preponderance of scientific data and known mechanisms of food-based constituents. It is suggested that such a consumer-oriented categorization of these plant-based foods may lead to greater recognition of their importance in the daily diet throughout the lifespan. Other adjunctive strategies to heighten awareness of fruits and vegetables are discussed.

Improvement in Cognition Following Double-Blind Randomized Micronutrient Interventions in the General Population

The impact of poor nutrition on physiological health is well understood (Costarelli et al., 2013). Less is known about the effects of diet on brain function and cognition in the general population (Ames, 2010; Parletta et al., 2013; White et al., 2017) and we are still in the early stages of understanding the role of specific nutrients to normal and pathological neuronal functioning. In the present study, the putative effect of a multivitamin/mineral or vitamin D supplement on cognitive function over an 8-week period was compared with volunteers taking vitamin C. Healthy adults (N = 60) were recruited, age range 21-59 years ( x ¯ = 39.07 years, SD = 11.46), with participants randomly allocated to conditions in a double-blind protocol. Participants also completed a 14-day food diary to gather information on micronutrient intake. The cognitive test battery included measures from the Wechsler Adult Intelligence Scale-III (WAIS-III; Wechsler et al., 2008), Wechsler Memory Scale-IV (WMS-IV; Wechsler, 2009) and Delis-Kaplan Executive Function System (D-KEFS; Delis et al., 2001), along with the Doors and People (Baddeley et al., 1994) and a serial reaction time task. Analyses showed better performance on some tasks in all groups following the intervention period, notably on measures of verbal and visual memory and visuomotor processing speed. The Multivitamin group showed significant improvements on tasks of visual strategy generation (along with the Vitamin C group), motor planning, explicit and implicit learning, and working memory. This evidence suggests that sub-optimal micronutrient intake may have a negative effect on cognition across the lifespan.

Phytochemicals for Improving Aspects of Cognitive Function and Psychological State Potentially Relevant to Sports Performance

Subjective alertness and optimal cognitive function, including in terms of attention, spatial/working memory and executive function, are intrinsic to peak performance in many sports. Consumption of a number of plant-derived 'secondary metabolite' phytochemicals can modulate these psychological parameters, although there is a paucity of evidence collected in a sporting context. The structural groups into which these phytochemicals fall-phenolics, terpenes and alkaloids-vary in terms of the ecological roles they play for the plant, their toxicity and the extent to which they exert direct effects on brain function. The phenolics, including polyphenols, play protective roles in the plant, and represent a natural, benign component of the human diet. Increased consumption has been shown to improve cardiovascular function and is associated with long-term brain health. However, whilst short-term supplementation with polyphenols has been shown to consistently modulate cerebral blood-flow parameters, evidence of direct effects on cognitive function and alertness/arousal is currently comparatively weak. Terpenes play both attractant and deterrent roles in the plant, and typically occur less frequently in the diet. Single doses of volatile monoterpenes derived from edible herbs such as sage (Salvia officinalis/lavandulaefolia) and peppermint (Mentha piperita), diterpene-rich Ginkgo biloba extracts and triterpene-containing extracts from plants such as ginseng (Panax ginseng/quinquefolius) and Bacopa monnieri have all been shown to enhance relevant aspects of cognitive function and alertness. The alkaloids play toxic defensive roles in the plant, including via interference with herbivore brain function. Whilst most alkaloids are inappropriate in a sporting context due to toxicity and legal status, evidence suggests that single doses of nicotine and caffeine may be able to enhance relevant aspects of cognitive function and/or alertness. However, their benefits may be confounded by habituation and withdrawal effects in the longer term. The efficacy of volatile terpenes, triterpene-rich extracts and products combining low doses of caffeine with other phytochemicals deserves more research attention.