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Wild blueberry (poly)phenols can improve vascular function and cognitive performance in healthy older individuals: a double-blind randomized controlled trial.
Wood, E, Hein, S, Mesnage, R, Fernandes, F, Abhayaratne, N, Xu, Y, Zhang, Z, Bell, L, Williams, C, Rodriguez-Mateos, A
The American journal of clinical nutrition. 2023;117(6):1306-1319
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The risk of developing both cardiovascular and neurodegenerative diseases increases with aging. Growing evidence from epidemiological and human intervention trials indicates that (poly)phenols may have cardioprotective properties as well as the ability to improve cognitive function. The aim of this study was to investigate the effects of daily wild blueberry (WBB) (poly)phenol consumption on vascular function and cognitive performance in healthy older individuals. This study was a randomised, double-blinded, placebo-controlled parallel design study. A total of 61 healthy older individuals were recruited and randomly assigned to one of the two arms; placebo intervention or blueberry intervention group. Results showed that long-term consumption of a dietary achievable amount of WBB enhanced vascular and cognitive function in older adults. Authors conclude that gut microbiota and vascular blood flow may play important roles in mediating the cognitive benefits shown by the consumption of (poly)phenol-rich foods.
Abstract
BACKGROUND Evidence suggests that the intake of blueberry (poly)phenols is associated with improvements in vascular function and cognitive performance. Whether these cognitive effects are linked to increases in cerebral and vascular blood flow or changes in the gut microbiota is currently unknown. METHODS A double-blind, parallel randomized controlled trial was conducted in 61 healthy older individuals aged 65-80 y. Participants received either 26 g of freeze-dried wild blueberry (WBB) powder (302 mg anthocyanins) or a matched placebo (0 mg anthocyanins). Endothelial function measured by flow-mediated dilation (FMD), cognitive function, arterial stiffness, blood pressure (BP), cerebral blood flow (CBF), gut microbiome, and blood parameters were measured at baseline and 12 wk following daily consumption. Plasma and urinary (poly)phenol metabolites were analyzed using microelution solid-phase extraction coupled with liquid chromatography-mass spectrometry. RESULTS A significant increase in FMD and reduction in 24 h ambulatory systolic BP were found in the WBB group compared with the placebo group (0.86%; 95% CI: 0.56, 1.17, P < 0.001; -3.59 mmHg; 95% CI: -6.95, -0.23, P = 0.037; respectively). Enhanced immediate recall on the auditory verbal learning task, alongside better accuracy on a task-switch task was also found following WBB treatment compared with placebo (P < 0.05). Total 24 h urinary (poly)phenol excretion increased significantly in the WBB group compared with placebo. No changes in the CBF or gut microbiota composition were found. CONCLUSIONS Daily intake of WBB powder, equivalent to 178 g fresh weight, improves vascular and cognitive function and decreases 24 h ambulatory systolic BP in healthy older individuals. This suggests that WBB (poly)phenols may reduce future CVD risk in an older population and may improve episodic memory processes and executive functioning in older adults at risk for cognitive decline. Clinical Trial Registration number in clinicaltrials.gov: NCT04084457.
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A combination of green tea, rhodiola, magnesium and B vitamins modulates brain activity and protects against the effects of induced social stress in healthy volunteers.
Boyle, NB, Billington, J, Lawton, C, Quadt, F, Dye, L
Nutritional neuroscience. 2022;25(9):1845-1859
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Stress is a leading cause of work-related time off. Low magnesium intake has been shown to be associated with anxiety and supplementation has been shown to relieve anxiety-related-symptoms, especially when combined with B vitamins. Green tea and rhodiola have also been used to alleviate stress, anxiety, and fatigue, the latter after just 3 days of intake. This randomised control trial of 100 moderately stressed adults aimed to determine the effects of combining magnesium, B vitamins, green tea, and rhodiola after induced social stress. The results showed that supplementation with a combination of magnesium, B vitamins, green tea, and rhodiola induced a relaxed, alert state and lowered stress, anxiety, and mood disturbances. However, it did not affect stress hormones, heart rate or blood pressure in response to stress. It was concluded that combination treatment is a promising therapy for stress. This study could be used by healthcare professionals to recommend the combination of magnesium, B vitamins, green tea, and rhodiola to individuals with social anxiety before they enter a socially stressful situation.
Abstract
BACKGROUND Magnesium (Mg), green tea and rhodiola extracts have, in isolation, been shown to possess stress and anxiety relieving effects. Green tea and rhodiola have been shown to modulate EEG oscillatory brain activity associated with relaxation and stress perception. The combined capacity of these ingredients to confer protective effects under conditions of acute stress has yet to be examined. We tested the hypothesis that a combination of Mg (with B vitamins) + green tea + rhodiola would acutely moderate the effects of stress exposure. METHODS A double blind, randomised, placebo controlled, parallel group design was employed (Clinicaltrials.gov:NCT03262376; 25/0817). One hundred moderately stressed adults received oral supplementation of either (i) Mg + B vitamins + green tea + rhodiola; (ii) Mg + B vitamins + rhodiola; (iii) Mg + B vitamins + green tea; or (iv) placebo. After supplementation participants were exposed to the Trier Social Stress Test. The effects of the study treatments on electroencephalogram (EEG) resting state alpha and theta, subjective state/mood, blood pressure, heart rate variability and salivary cortisol responses after acute stress exposure were assessed. RESULTS The combined treatment significantly increased EEG resting state theta (p < .02) - considered indicative of a relaxed, alert state, attenuated subjective stress, anxiety and mood disturbance, and heightened subjective and autonomic arousal (p < .05). CONCLUSIONS Mg, B vitamins, rhodiola and green tea extracts are a promising combination of ingredients that may enhance coping capacity and offer protection from the negative effects of stress exposure.Trial registration: ClinicalTrials.gov identifier: NCT03262376.
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Probiotic Mixture Containing Lactobacillus helveticus, Bifidobacterium longum and Lactiplantibacillus plantarum Affects Brain Responses to an Arithmetic Stress Task in Healthy Subjects: A Randomised Clinical Trial and Proof-of-Concept Study.
Edebol Carlman, HMT, Rode, J, König, J, Repsilber, D, Hutchinson, AN, Thunberg, P, Persson, J, Kiselev, A, Pruessner, JC, Brummer, RJ
Nutrients. 2022;14(7)
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Physiological and psychological stress can affect gut function and its interaction with the brain (gut-brain axis). Different types of stress and different phases of stress regulation can affect the brain in different ways. Manipulation of the gut microbiota using probiotic bacteria has been shown to improve cognition and stress response. However, probiotic interventions are likely to have different effects depending on the strains used. The aim of this study was to assess the effects of a probiotic intervention on brain activity and stress response. This study is a randomised double-blinded placebo-controlled crossover study with 22 healthy subjects. Subjects were randomised to two study groups receiving the intervention in different orders (probiotics or placebo first). Results demonstrate that the probiotic intervention: - altered activity in specific brain regions known to regulate emotion and stress response. - significantly altered functional connectivity between the upper limbic and medioventral regions. - did not affect the activation of other limbic or subcortical areas. Authors conclude that their findings could further lead to possible clinical implications for improving stress resilience and potential roles in the treatment of affective and gut-brain axis disorders.
Abstract
Probiotics are suggested to impact physiological and psychological stress responses by acting on the gut-brain axis. We investigated if a probiotic product containing Bifidobacterium longum R0175, Lactobacillus helveticus R0052 and Lactiplantibacillus plantarum R1012 affected stress processing in a double-blinded, randomised, placebo-controlled, crossover proof-of-concept study (NCT03615651). Twenty-two healthy subjects (24.2 ± 3.4 years, 6 men/16 women) underwent a probiotic and placebo intervention for 4 weeks each, separated by a 4-week washout period. Subjects were examined by functional magnetic resonance imaging while performing the Montreal Imaging Stress Task (MIST) as well as an autonomic nervous system function assessment during the Stroop task. Reduced activation in regions of the lateral orbital and ventral cingulate gyri was observed after probiotic intervention compared to placebo. Significantly increased functional connectivity was found between the upper limbic region and medioventral area. Interestingly, probiotic intervention seemed to predominantly affect the initial stress response. Salivary cortisol secretion during the task was not altered. Probiotic intervention did not affect cognitive performance and autonomic nervous system function during Stroop. The probiotic intervention was able to subtly alter brain activity and functional connectivity in regions known to regulate emotion and stress responses. These findings support the potential of probiotics as a non-pharmaceutical treatment modality for stress-related disorders.
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The Effect of a High-Dose Vitamin B Multivitamin Supplement on the Relationship between Brain Metabolism and Blood Biomarkers of Oxidative Stress: A Randomized Control Trial.
Ford, TC, Downey, LA, Simpson, T, McPhee, G, Oliver, C, Stough, C
Nutrients. 2018;10(12)
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A diet rich in vitamins and micronutrients, particularly B vitamins, is essential for body and brain functionality. B vitamin supplementation has been found to reduce depression, enhance mood, lessen anxiety and improve cognition. New neuroimaging techniques have shed light on the relationship between blood and neural biomarkers, connecting diet quality and brain function. The aim of this randomised, placebo-controlled, double-blind trial was to investigate the effect of 6-month high-dose B-vitamin supplementation on neural and blood biomarkers of metabolism in 32 healthy adults. Participants were randomised to consume either B-vitamin supplementation or placebo pills twice a day for six months and underwent blood tests and brain imaging before and after supplementation. This study found supplementation effectively increased vitamin B6 and B12 levels and reduced homocysteine with no changes in folate as compared with placebo. Supplementation promoted neural metabolic pathways and reduced oxidative stress and inflammation. Based on these findings, the authors conclude B-group vitamins are important for maintaining brain health in healthy adults and may play a role in prevention and alleviation of neural disease and disability.
Abstract
A diet rich in B-group vitamins is essential for optimal body and brain function, and insufficient amounts of such vitamins have been associated with higher levels of neural inflammation and oxidative stress, as marked by increased blood plasma homocysteine. Neural biomarkers of oxidative stress quantified through proton magnetic spectroscopy (1H-MRS) are not well understood, and the relationship between such neural and blood biomarkers is seldom studied. The current study addresses this gap by investigating the direct effect of 6-month high-dose B-group vitamin supplementation on neural and blood biomarkers of metabolism. Using a randomized, double-blind, placebo-controlled design, 32 healthy adults (20 female, 12 male) aged 30⁻65 years underwent blood tests (vitamin B6, vitamin B12, folate, and homocysteine levels) and 1H-MRS of the posterior cingulate cortex (PCC) and dorsolateral prefrontal cortex (DLPFC) before and after supplementation. Results confirmed the supplement was effective in increasing vitamin B6 and vitamin B12 levels and reducing homocysteine, whereas there was no change in folate levels. There were significant relationships between vitamin B6 and N-acetylaspartate (NAA), choline, and creatine, as well as between vitamin B12 and creatine (ps < 0.05), whereas NAA in the PCC increased, albeit not significantly (p > 0.05). Together these data provide preliminary evidence for the efficacy of high-dose B-group supplementation in reducing oxidative stress and inflammation through increasing oxidative metabolism. It may also promote myelination, cellular metabolism, and energy storage.
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Brain atrophy in cognitively impaired elderly: the importance of long-chain ω-3 fatty acids and B vitamin status in a randomized controlled trial.
Jernerén, F, Elshorbagy, AK, Oulhaj, A, Smith, SM, Refsum, H, Smith, AD
The American journal of clinical nutrition. 2015;102(1):215-21
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Mild cognitive impairment (MCI) is a characterised by a decline in cognitive function between normal aging and the development of dementia. While brain atrophy occurs in normal aging, patients with MCI or dementia exhibit much higher rates of atrophy. Results from a recent trial demonstrated that homocysteine-lowering B vitamins resulted in a significant reduction in brain atrophy rates, and links between omega-3 fatty acids and homocysteine have been suggested. The purpose of this study was to investigate whether plasma omega-3 fatty acid concentrations modify the treatment effect of B vitamins on brain atrophy rates among 168 elderly adults with MCI. Participants were randomly assigned to receive placebo or high-dose vitamin B supplementation and both brain scans and plasma concentrations were done at baseline and 2 years. The findings of this study demonstrated that, in patients with high omega-3 plasma concentrations, B vitamin supplementation slowed brain atrophy by 40% compared with those in the placebo group. This indicates that the effect of B vitamin supplementation on brain atrophy rates depend on plasma omega-3 fatty acid concentrations.
Abstract
BACKGROUND Increased brain atrophy rates are common in older people with cognitive impairment, particularly in those who eventually convert to Alzheimer disease. Plasma concentrations of omega-3 (ω-3) fatty acids and homocysteine are associated with the development of brain atrophy and dementia. OBJECTIVE We investigated whether plasma ω-3 fatty acid concentrations (eicosapentaenoic acid and docosahexaenoic acid) modify the treatment effect of homocysteine-lowering B vitamins on brain atrophy rates in a placebo-controlled trial (VITACOG). DESIGN This retrospective analysis included 168 elderly people (≥70 y) with mild cognitive impairment, randomly assigned either to placebo (n = 83) or to daily high-dose B vitamin supplementation (folic acid, 0.8 mg; vitamin B-6, 20 mg; vitamin B-12, 0.5 mg) (n = 85). The subjects underwent cranial magnetic resonance imaging scans at baseline and 2 y later. The effect of the intervention was analyzed according to tertiles of baseline ω-3 fatty acid concentrations. RESULTS There was a significant interaction (P = 0.024) between B vitamin treatment and plasma combined ω-3 fatty acids (eicosapentaenoic acid and docosahexaenoic acid) on brain atrophy rates. In subjects with high baseline ω-3 fatty acids (>590 μmol/L), B vitamin treatment slowed the mean atrophy rate by 40.0% compared with placebo (P = 0.023). B vitamin treatment had no significant effect on the rate of atrophy among subjects with low baseline ω-3 fatty acids (<390 μmol/L). High baseline ω-3 fatty acids were associated with a slower rate of brain atrophy in the B vitamin group but not in the placebo group. CONCLUSIONS The beneficial effect of B vitamin treatment on brain atrophy was observed only in subjects with high plasma ω-3 fatty acids. It is also suggested that the beneficial effect of ω-3 fatty acids on brain atrophy may be confined to subjects with good B vitamin status. The results highlight the importance of identifying subgroups likely to benefit in clinical trials. This trial was registered at www.controlled-trials.com as ISRCTN94410159.
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Zinc supplementation in the treatment of anorexia nervosa.
Brazilian Association of Nutrology
Revista da Associacao Medica Brasileira (1992). 2013;59(4):321-4
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Anorexia nervosa (AN) is a disorder characterised by significant weight loss, restrictive diets, a search for thinness and a distortion of body image. Zinc is a key micronutrient that plays essential roles in the body including in gene transcription regulation and enzyme reactions. There is a similarity between symptoms of zinc deficiency and AN; namely weight loss, changes in appetite and sexual dysfunction. This review aims to provide healthcare professionals with insight into the nutritional recommendations for zinc in patients with AN. The review suggests that there are clinical studies demonstrating a strong association between AN and low levels of serum zinc and low levels of urinary zinc suggesting a micronutrient deficiency in these individuals. The severity of zinc deficiency is associated with greater weight deficits and longer AN duration. It is also associated with higher levels of anxiety and depression in AN individuals. Zinc is key in smell and taste perception and the brain regions associated with interpreting eating as pleasurable. Reduced food intake and practices like purging and low-zinc diets may exacerbate any low levels and impair zinc absorption. A controlled study showed that oral supplementation resulted in a higher rate of body mass index (BMI) increase and an improvement in neurotransmitters. The review recommends: 1. Check serum levels of zinc in AN patients as it may be low. Zinc status may contribute to eating behaviour including gaining pleasure from eating, smell and taste. 2. Zinc supplementation of 15mg/daily for preventative purposes and 15-20mg/daily if zinc deficiency is identified after testing. The review recommends supplementation for a minimum of 2 months.