Dietary Cocoa Flavanols Do Not Alter Brain Excitability in Young Healthy Adults

The ingestion of dietary cocoa flavanols acutely alters functions of the cerebral endothelium, but whether the effects of flavanols permeate beyond this to alter other brain functions remains unclear. Based on converging evidence, this work tested the hypothesis that cocoa flavanols would alter brain excitability in young healthy adults. In a randomised, cross-over, double-blinded, placebo-controlled design, transcranial magnetic stimulation was used to assess corticospinal and intracortical excitability before as well as 1 and 2 h post-ingestion of a beverage containing either high (695 mg flavanols, 150 mg (−)-epicatechin) or low levels (5 mg flavanols, 0 mg (−)-epicatechin) of cocoa flavanols. In addition to this acute intervention, the effects of a short-term chronic intervention where the same cocoa flavanol doses were ingested once a day for 5 consecutive days were also investigated. For both the acute and chronic interventions, the results revealed no robust alteration in corticospinal or intracortical excitability. One possibility is that cocoa flavanols yield no net effect on brain excitability, but predominantly alter functions of the cerebral endothelium in young healthy adults. Future studies should increase intervention durations to maximize the acute and chronic accumulation of flavanols in the brain, and further investigate if cocoa flavanols would be more effective at altering brain excitability in older adults and clinical populations than in younger adults

Fat Consumption Attenuates Cortical Oxygenation during Mental Stress in Young Healthy Adults

Mental stress has been associated with cardiovascular events and stroke, and has also been linked with poorer brain function, likely due to its impact on cerebral vasculature. During periods of stress, individuals often increase their consumption of unhealthy foods, especially high-fat foods. Both high-fat intake and mental stress are known to impair endothelial function, yet few studies have investigated the effects of fat consumption on cerebrovascular outcomes during periods of mental stress. Therefore, this study examined whether a high-fat breakfast prior to a mental stress task would alter cortical oxygenation and carotid blood flow in young healthy adults. In a randomised, counterbalanced, cross-over, postprandial intervention study, 21 healthy males and females ingested a high-fat (56.5 g fat) or a low-fat (11.4 g fat) breakfast 1.5 h before an 8-min mental stress task. Common carotid artery (CCA) diameter and blood flow were assessed at pre-meal baseline, 1 h 15 min post-meal at rest, and 10, 30, and 90 min following stress. Pre-frontal cortex (PFC) tissue oxygenation (near-infrared spectroscopy, NIRS) and cardiovascular activity were assessed post-meal at rest and during stress. Mental stress increased heart rate, systolic and diastolic blood pressure, and PFC tissue oxygenation. Importantly, the high-fat breakfast reduced the stress-induced increase in PFC tissue oxygenation, despite no differences in cardiovascular responses between high- and low-fat meals. Fat and stress had no effect on resting CCA blood flow, whilst CCA diameter increased following consumption of both meals. This is the first study to show that fat consumption may impair PFC perfusion during episodes of stress in young healthy adults. Given the prevalence of consuming high-fat foods during stressful periods, these findings have important implications for future research to explore the relationship between food choices and cerebral haemodynamics during mental stress

(-)-Epicatechin and its colonic metabolite hippuric acid protect against dexamethasone-induced atrophy in skeletal muscle cells

Cocoa flavanols have been shown to improve muscle function and may offer a novel approach to protect against muscle atrophy. Hippuric acid (HA) is a colonic metabolite of (-)-epicatechin (EPI), the primary bioactive compound of cocoa, and may be responsible for the associations between cocoa supplementation and muscle metabolic alterations. Accordingly, we investigated the effects of EPI and HA upon skeletal muscle morphology and metabolism within an in vitro model of muscle atrophy. Under atrophy-like conditions (24h 100μM dexamethasone (DEX)), C2C12 myotube diameter was significantly greater following co-incubation with either 25μM HA (11.19±0.39μm) or 25μM EPI (11.01±0.21μm) compared to the vehicle control (VC; 7.61±0.16μm, both P < .001). In basal and leucine-stimulated states, there was a significant reduction in myotube protein synthesis (MPS) rates following DEX treatment in VC (P = .024). Interestingly, co-incubation with EPI or HA abrogated the DEX-induced reductions in MPS rates, whereas no significant differences versus control treated myotubes (CTL) were noted. Furthermore, co-incubation with EPI or HA partially attenuated the increase in proteolysis seen in DEX-treated cells, preserving LC3 α/β II:I and caspase-3 protein expression in atrophy-like conditions. The protein content of PGC1α, ACC, and TFAM (regulators of mitochondrial function) were significantly lower in DEX-treated versus. CTL cells (all P < .050). However, co-incubation with EPI or HA was unable to prevent these DEX-induced alterations. For the first time we demonstrate that EPI and HA exert anti-atrophic effects on C2C12 myotubes, providing novel insight into the association between flavanol supplementation and favourable effects on muscle health

Flavanone-rich citrus beverages counteract the transient decline in postprandial endothelial function in humans: a randomised, controlled, double-masked, cross-over intervention study

Specific flavonoid-rich foods/beverages are reported to exert positive effects on vascular function; however, data relating to effects in the postprandial state are limited. The present study investigated the postprandial, time-dependent (0–7 h) impact of citrus flavanone intake on vascular function. An acute, randomised, controlled, double-masked, cross-over intervention study was conducted by including middle-aged healthy men (30–65 years, n 28) to assess the impact of flavanone intake (orange juice: 128·9 mg; flavanone-rich orange juice: 272·1 mg; homogenised whole orange: 452·8 mg; isoenergetic control: 0 mg flavanones) on postprandial (double meal delivering a total of 81 g of fat) endothelial function. Endothelial function was assessed by flow-mediated dilatation (FMD) of the brachial artery at 0, 2, 5 and 7 h. Plasma levels of paringenin/hesperetin metabolites (sulphates and glucuronides) and nitric oxide species were also measured. All flavanone interventions were effective at attenuating transient impairments in FMD induced by the double meal (7 h post intake; P <0·05), but no dose–response effects were observed. The effects on FMD coincided with the peak of naringenin/hesperetin metabolites in circulation (7 h) and sustained levels of plasma nitrite. In summary, citrus flavanones are effective at counteracting the negative impact of a sequential double meal on human vascular function, potentially through the actions of flavanone metabolites on nitric oxide

The mediating role of self-criticism, experiential avoidance and negative urgency on the relationship between ED-related symptoms and difficulties in emotion regulation

Objective: Difficulties in emotion regulation are thought to play a transdiagnostic role across eating disorders (ED). In the current study, we explored with a path analysis the mediating role of self-criticism, experiential avoidance and negative urgency on the relationship between ED-related symptoms and dimensions of difficulties in emotion regulation. Method: Participants were 103 female outpatients recruited at a Portuguese ED hospital unit, diagnosed with an ED, aged 14–60 years old (M = 28.0, SD = 10.5), body mass index (BMI) ranging from 11.72 to 39.44 (M = 20.1, SD = 5.4). Results: The path analysis resulted in a model with an adequate fit to the data (SRMR = 0.05; RMSEA = 0.07 [0.00, 0.12], PCLOSE = 0.269; TLI = 0.97; IFI = 0.99; GFI = 0.95). A final model in which the relationship between ED-related symptoms and dimensions of difficulties in emotion regulation was mediated by self-criticism, experiential avoidance and negative urgency, accounted for a variance of 71% for strategies, 57% for non-acceptance, 62% for impulses, 56% for goals and 20% for clarity. Conclusion: Results suggest that self-criticism, experiential avoidance and negative urgency, combined, are relevant in the relationship between ED-related symptoms and difficulties in emotion regulation. ED treatment and emotion regulation skills may be enhanced through the inclusion of specific components that target self-criticism, experiential avoidance and negative urgency, as they become prominent during the therapeutic process.FCT - Fundação para a Ciência e a Tecnologia(POCI‐01‐0145‐FEDER‐028145

Impact of COVID-19 lockdown measures on a cohort of eating disorders patients

BackgroundLockdown implemented to prevent the COVID-19 spread resulted in marked changes in the lifestyle. The objective of the current study was to assess the impact of lockdown measures on a cohort of eating disorder (ED) patients being followed as part of an ongoing naturalistic treatment study.MethodsNinety-nine patients aged 18 or older, currently or previously, in treatment at a Portuguese specialized hospital unit were contacted by phone and invited to participate in the current survey. Fifty-nine agreed to be interviewed by phone, and 43 agreed to respond to a set of self-report measures of ED symptoms, emotion regulation difficulties, clinical impairment, negative urgency, and COVID-19 impact, during the week after the end of the lockdown period.ResultsData showed that of the 26 patients currently in treatment: 8 remained unchanged (31%), 7 deteriorated (27%), and 11 reliably improved (42%). Of the 17 participants not currently in treatment: 3 deteriorated (18%), 9 remained unchanged (53%), and 5 (29%) improved after the lockdown period. The Coronavirus Impact Scale showed that most patients considered their routines moderately or extremely impacted, experienced stress related to coronavirus, and showed difficulty in maintaining physical exercise and feeding routines. Results suggest that higher impact of COVID-19 lockdown was significantly correlated with eating disorder symptoms and associated psychopathology, impulsivity, difficulties in emotion regulation and clinical impairment measured at post-lockdown. In addition, the impact of COVID-19 and lockdown measures on clinical impairment was mediated by difficulties in emotion regulation.ConclusionsFindings suggest that some ED patients may experience worsening of their condition, especially if associated with difficulties in emotion regulation, and these difficulties might be exacerbated in the context of a stressful crisis and lockdown measures, highlighting the need for intervention strategies to mitigate its negative impact.This work was conducted at the Psychology Research Centre (PSI/01662), School of Psychology, University of Minho, and partially supported by the Portuguese Foundation for Science and Technology and the Portuguese Ministry of Science, Technology and Higher Education (UID/PSI/01662/2019), through the national funds (PIDDAC); and a grant by the Portuguese Foundation for Science and Technology and the Portuguese Ministry of Science, Technology and Higher Education through national funds and cofinanced by FEDER through COMPETE2020 under the PT2020 Partnership Agreement (POCI-01-0145-FEDER-028145) to P. Machado PI)

Flavonoids as modulators of memory and learning: molecular interactions resulting in behavioural effects

There is considerable interest in the potential of a group of dietary-derived phytochemicals known as flavonoids in modulating neuronal function and thereby influencing memory, learning and cognitive function. The present review begins by detailing the molecular events that underlie the acquisition and consolidation of new memories in the brain in order to provide a critical background to understanding the impact of flavonoid-rich diets or pure flavonoids on memory. Data suggests that despite limited brain bioavailability, dietary supplementation with flavonoid-rich foods, such as blueberry, green tea and Ginkgo biloba lead to significant reversals of age-related deficits on spatial memory and learning. Furthermore, animal and cellular studies suggest that the mechanisms underpinning their ability to induce improvements in memory are linked to the potential of absorbed flavonoids and their metabolites to interact with and modulate critical signalling pathways, transcription factors and gene and/or protein expression which control memory and learning processes in the hippocampus; the brain structure where spatial learning occurs. Overall, current evidence suggests that human translation of these animal investigations are warranted, as are further studies, to better understand the precise cause-and-effect relationship between flavonoid intake and cognitive outputs