Does medicinal cannabis affect depression, anxiety, and stress in people with cancer? A systematic review and meta-analysis of intervention studies.

INTRODUCTION: Medicinal cannabis might have a role in supporting the mental health of people with cancer. This systematic review and meta-analysis examined the efficacy and safety of medicinal cannabis, compared with any control, as an intervention for depression, anxiety, and stress symptoms in people living with cancer. A secondary aim was to examine the effect of low versus high Δ9-tetrahydrocannabinol (THC) dose on these outcomes. METHODS: Five databases were systematically searched, and complemented with a snowball search from inception to May 2023, for any type of interventional study that included humans of any age with any cancer type. Primary outcomes were incidence and severity of depression, anxiety, and stress symptoms. Secondary outcomes were mood, cognition, quality of life, appetite, nutrition status, gastrointestinal symptoms, and adverse events. Data were pooled using Review Manager. Evidence was appraised using Cochrane risk of bias tools. Confidence in the estimated effect of pooled outcomes was assessed using Grading of Recommendations, Assessment, Development and Evaluation (GRADE). RESULTS: Fifteen studies (n = 11 randomized trials, n = 4 non-randomized trials) of 18 interventions (N = 1898 total participants; 100 % ≥18 years of age) were included. Ten studies examined THC (70 % synthetic), two synthetic cannabidiol with or without THC, and six whole-plant extracts. No clinically significant effects of medicinal cannabis were found on primary outcomes. The likelihood of anxiety events increased with higher-dose synthetic THC compared with a lower dose (OR: 2.0; 95 % CI: 1.4, 2.9; p < 0.001; Confidence: very low). Medicinal cannabis (THC, cannabidiol, and whole-plant extract) increased the likelihood of improved appetite (OR: 12.3; 95 % CI: 3.5, 45.5; p < 0.001; n = 3 interventions; Confidence: moderate) and reduced severity of appetite loss (SMD: -0.4; 95 % CI: -0.8, -0.1; p = 0.009; Confidence: very low). There was very low confidence that higher doses of synthetic THC increased the likelihood of any adverse event (OR: 0.5; 95 % CI: 0.3, 0.7; p < 0.001). Medicinal cannabis had no effect on emotional functioning, mood changes, confusion, disorientation, quality of life, and gastrointestinal symptoms. Confidence in findings was limited by some studies having high or unclear risk of bias and imprecise pooled estimates. CONCLUSIONS: There was insufficient evidence to determine the efficacy and safety of medicinal cannabis as a therapeutic intervention for depression, anxiety, or stress in people with active cancer. Further research should explore whether medicinal cannabis might improve and maintain appetite and if high-dose synthetic THC might increase the incidence of side-effects, including anxiety. To inform clinical practice, well-powered and rigorously designed trials are warranted that evaluate the effects of medicinal cannabis prescribed to target anxiety, depression, and stress.

Fiber intake and risk of chronic obstructive pulmonary disease: A systematic review and dose response meta-analysis.

This systematic review and dose-response meta-analysis examined the risk of chronic obstructive pulmonary disease (COPD) following dietary fiber intake. Relevant articles were retrieved from a variety of databases, including Scopus, Embase, and Medline, until March 2023. Spirometry was the most frequently used method for determining the presence of COPD. Based on the search, there were a total of 213,912 participants across five separate studies. Random effects model was used to combine the data and a dose-response analysis was further conducted. Five distinct cohort studies were identified. Based on highest versus lowest analysis, there was an inverse correlation between the intake of total fiber (RR, 0.72; 95%, CI: 0.64-0.80), cereal fiber (RR: 0.76, 95% CI 0.68, 0.86), and fruit fiber (RR: 0.75, 95% CI: 0.68, 0.83). Although this result was not significant for vegetable fiber (RR, 0.95; 95% CI, 0.84-1.07). Dose-response analysis revealed that daily increase of 10 g of total dietary fiber, cereal fiber, or fruit fiber reduced the risk of COPD by 26%, 21%, and 37%, respectively. The ROBINS-E tool classified all cohort studies as having a moderate risk of bias. Total fiber, cereal fiber, and fruit fiber intake were found to have low credibility using the NutriGrade tool. Additionally, there is a lack of scientific evidence supporting the use of vegetable fiber. Larger, more comprehensive studies are required to confirm these findings.

Polyphenols as novel interventions for depression: Exploring the efficacy, mechanisms of action, and implications for future research.

Numerous animal and human studies have assessed the relationship between polyphenols and outcomes related to depression. However, no comprehensive synthesis of the main findings has been conducted. The aim of this manuscript was to systematically review the available evidence from animal and human studies on the association and the effects of dietary polyphenols on depression and provide recommendations for future research. We based our review on 163 preclinical animal, 16 observational and 44 intervention articles assessing the relationship between polyphenols and outcomes related to depression. Most animal studies demonstrated that exposure to polyphenols alleviated behaviours reported to be associated with depression. However, human studies are less clear, with some studies reporting an inverse relationship between the intake of some polyphenols, and polyphenol rich foods and depression risk and symptoms, while others reporting no association or effect. Hence, while there has been extensive research conducted in animals and there is some supporting evidence in humans, further human studies are required, particularly in younger and clinical populations.

The effect of omega-3 fatty acids supplementation on inflammatory biomarkers in subjects with migraine: a randomized, double-blind, placebo-controlled trial.

OBJECTIVE: Imbalances in immune regulation are important features of migraine pathophysiology. In line with this, the current study investigated the efficacy of omega-3 fatty acids supplementation on inflammatory and anti-inflammatory markers in patients with migraines. MATERIALS AND METHODS: This randomized, double-blind, placebo-controlled trial consisted of 40 patients that were prone to experiencing episodic migraines. For two months, participants were randomized into one group that received omega-3 supplementation (n= 20), 600 mg of EPA and 300 mg of DHA, twice daily) or another group that received a placebo (n= 20). Transforming growth factor ß (TGF-ß), interleukin (IL)-4, interferon-gamma (IFN-γ), and interleukin (IL)-17 serum levels were assessed using enzyme-linked immunosorbent assay methods at baseline and following the intervention. The current study was registered on ClinicalTrials.gov with the registration number NCT02532023. RESULTS: After two months of intervention, the administration of omega-3 fatty acids resulted in a significant rise in the concentrations of anti-inflammatory cytokine IL-4 (p=0.010) as well as a significant reduction in concentrations of pro-inflammatory cytokine IFN-γ (p=0.001) compared with the placebo. However, no significant changes were observed in serum TGF-ß and IL-17 levels. DISCUSSION: Our findings indicated consumption of omega-3 fatty acids may have a potentially beneficial response on the inflammatory immune response in patients with migraines. Larger trials are needed to corroborate these findings.

High ultra-processed food consumption is associated with elevated psychological distress as an indicator of depression in adults from the Melbourne Collaborative Cohort Study.

BACKGROUND: Few studies have tested longitudinal associations between ultra-processed food consumption and depressive outcomes. As such, further investigation and replication are necessary. The aim of this study is to examine associations of ultra-processed food intake with elevated psychological distress as an indicator of depression after 15 years. METHOD: Data from the Melbourne Collaborative Cohort Study (MCCS) were analysed (n = 23,299). We applied the NOVA food classification system to a food frequency questionnaire (FFQ) to determine ultra-processed food intake at baseline. We categorised energy-adjusted ultra-processed food consumption into quartiles by using the distribution of the dataset. Psychological distress was measured by the ten-item Kessler Psychological Distress Scale (K10). We fitted unadjusted and adjusted logistic regression models to assess the association of ultra-processed food consumption (exposure) with elevated psychological distress (outcome and defined as K10 ≥ 20). We fitted additional logistic regression models to determine whether these associations were modified by sex, age and body mass index. RESULTS: After adjusting for sociodemographic characteristics and lifestyle and health-related behaviours, participants with the highest relative intake of ultra-processed food were at increased odds of elevated psychological distress compared to participants with the lowest intake (aOR: 1.23; 95%CI: 1.10, 1.38, p for trend = 0.001). We found no evidence for an interaction of sex, age and body mass index with ultra-processed food intake. CONCLUSION: Higher ultra-processed food intake at baseline was associated with subsequent elevated psychological distress as an indicator of depression at follow-up. Further prospective and intervention studies are necessary to identify possible underlying pathways, specify the precise attributes of ultra-processed food that confer harm, and optimise nutrition-related and public health strategies for common mental disorders.

Metabolically Healthy Overweight and Obesity, Transition to Metabolically Unhealthy Status and Cognitive Function: Results from the Framingham Offspring Study.

AIMS: To evaluate the association between metabolically healthy overweight/obesity (MHO) status and longitudinal cognitive function while also considering the stability of the condition. METHODS: In total, 2892 participants (mean age 60.7 (9.4) years) from Framingham Offspring Study completed health assessments every four years since 1971. Neuropsychological testing was repeated every four years starting from 1999 (Exam 7) to 2014 (Exam 9) (mean follow-up: 12.9 (3.5) years). Standardized neuropsychological tests were constructed into three factor scores (general cognitive performance, memory, processing speed/executive function). Healthy metabolic status was defined as the absence of all NCEP ATP III (2005) criteria (excluding waist circumference). MHO participants who scored positively for one or more of NCEP ATPIII parameters in the follow-up period were defined as unresilient MHO. RESULTS: No significant difference on the change in cognitive function over time was observed between MHO and metabolically healthy normal weight (MHN) individuals (all p > 0.05). However, a lower processing speed/executive functioning scale score was observed in unresilient MHO participants compared to resilient MHO participants (ß = -0.76; 95% CI = -1.44, -0.08; p = 0.030). CONCLUSIONS: Retaining a healthy metabolic status over time represents a more important discriminant in shaping cognitive function compared to body weight alone.

Nutritional and Behavioral Countermeasures as Medication Approaches to Relieve Motion Sickness: A Comprehensive Review.

The mismatch in signals perceived by the vestibular and visual systems to the brain, also referred to as motion sickness syndrome, has been diagnosed as a challenging condition with no clear mechanism. Motion sickness causes undesirable symptoms during travel and in virtual environments that affect people negatively. Treatments are directed toward reducing conflicting sensory inputs, accelerating the process of adaptation, and controlling nausea and vomiting. The long-term use of current medications is often hindered by their various side effects. Hence, this review aims to identify non-pharmacological strategies that can be employed to reduce or prevent motion sickness in both real and virtual environments. Research suggests that activation of the parasympathetic nervous system using pleasant music and diaphragmatic breathing can help alleviate symptoms of motion sickness. Certain micronutrients such as hesperidin, menthol, vitamin C, and gingerol were shown to have a positive impact on alleviating motion sickness. However, the effects of macronutrients are more complex and can be influenced by factors such as the food matrix and composition. Herbal dietary formulations such as Tianxian and Tamzin were shown to be as effective as medications. Therefore, nutritional interventions along with behavioral countermeasures could be considered as inexpensive and simple approaches to mitigate motion sickness. Finally, we discussed possible mechanisms underlying these interventions, the most significant limitations, research gaps, and future research directions for motion sickness.

In response to "Adherence to the Mediterranean diet and risk of depression: a systematic review and updated meta-analysis of observational studies".

The growing interest in the association between dietary patterns and depression risk is reflected by an increasing number of meta-analyses conducted recently on this topic. One of these meta-analyses found no evidence of a significant association between adherence to a Mediterranean diet and depression, when using prospective studies. This is an interesting finding, yet it is largely inconsistent with other meta-analyses published within the same time frame. The aim of this letter is to identify key analytic decisions made in that meta-analysis that may help explain the findings, specifically those regarding study inclusion criteria, outcome selection, and coding that may have affected the results of the analysis. After conducting the subsequent re-analysis addressing these revised methodological decisions, these decisions were found to largely explain the reported null result. These new findings not only provide greater context for the results of the meta-analysis but also explain why the findings were inconsistent with the relevant literature in this field.

Nutritional interventions for the prevention and treatment of cancer therapy-induced oral mucositis: an umbrella review of systematic reviews and meta-analysis.

CONTEXT: To date, the efficacy of nutritional interventions on oral mucositis (OM) in patients with cancer, and the quality of this evidence have not been explored. OBJECTIVE: The goal of this umbrella review was to provide a comprehensive evaluation of nutritional interventions for patients with cancer with OM, as well as to assess the quality of this evidence. DATA SOURCES: Meta-analyses were searched for using PubMed, Scopus, and ISI Web of Science databases until December 2021, with no time restrictions. DATA EXTRACTION: Meta-analyses of randomized control trials that evaluated the effects of nutritional interventions on the incidence of OM in patients with cancer had inclusion criteria for this umbrella review. Data extraction, quality assessment of meta-analyses, and primary studies were done independently by 2 authors. The Grading of Recommendations Assessment, Development, and Evaluation technique was used to grade the certainty of evidence. DATA ANALYSIS: A total of 26 meta-analyses were included in this umbrella review. The results showed that honey, glutamine, and propolis can reduce the incidence of severe OM, based on moderate evidence quality. In addition, zinc supplementation significantly reduced the incidence of OM, regardless of symptom severity; however, low certainty of the evidence was observed. The effects of vitamin E, curcumin, and probiotics on OM were not statistically significant. CONCLUSION: This umbrella review shows that honey, glutamine, and propolis can significantly reduce the incidence of severe OM. These findings need to be confirmed with well-designed, longitudinal randomized controlled trials. SYSTEMATIC REVIEW REGISTRATION: PROSPERO registration no. CRD42022301010.

Peri-Operative Risk Factors Associated with Post-Operative Cognitive Dysfunction (POCD): An Umbrella Review of Meta-Analyses of Observational Studies.

This umbrella review aimed to systematically identify the peri-operative risk factors associated with post-operative cognitive dysfunction (POCD) using meta-analyses of observational studies. To date, no review has synthesised nor assessed the strength of the available evidence examining risk factors for POCD. Database searches from journal inception to December 2022 consisted of systematic reviews with meta-analyses that included observational studies examining pre-, intra- and post-operative risk factors for POCD. A total of 330 papers were initially screened. Eleven meta-analyses were included in this umbrella review, which consisted of 73 risk factors in a total population of 67,622 participants. Most pertained to pre-operative risk factors (74%) that were predominantly examined using prospective designs and in cardiac-related surgeries (71%). Overall, 31 of the 73 factors (42%) were associated with a higher risk of POCD. However, there was no convincing (class I) or highly suggestive (class II) evidence for associations between risk factors and POCD, and suggestive evidence (class III) was limited to two risk factors (pre-operative age and pre-operative diabetes). Given that the overall strength of the evidence is limited, further large-scale studies that examine risk factors across various surgery types are recommended.

Association between animal protein sources and risk of neurodegenerative diseases: a systematic review and dose-response meta-analysis.

CONTEXT: Current findings about the differential effects of various sources of dietary animal protein on the risk of neurodegenerative diseases are contradictory. OBJECTIVE: The current meta-analysis was conducted to investigate the associations between intake of dietary animal protein sources and the risk of neurodegenerative diseases. DATA SOURCES: PubMed, Scopus, Web of Science, and Google Scholar databases were searched systematically until October 2021. DATA EXTRACTION: Prospective cohort studies exploring the association between consumption of animal protein sources and risk of neurodegenerative diseases in the general population were included. Among 10 571 identified studies, 33 prospective cohort studies met the eligibility criteria. DATA ANALYSIS: Dietary fish consumption was associated with a reduced risk of Alzheimer's disease (RR = 0.75; 95%CI, 0.57-0.97), dementia (RR = 0.84; 95%CI, 0.75-0.93), and cognitive impairment (RR = 0.85; 95%CI, 0.81-0.95). The risk of developing Parkinson's disease was significantly higher among those in the highest vs the lowest intake categories of total dairy (RR = 1.49; 95%CI, 1.06-2.10) and milk (RR = 1.40; 95%CI, 1.13-1.73). Moreover, dietary intake of total dairy (RR = 0.89; 95%CI, 0.80-0.99), total meat (RR = 0.72; 95%CI, 0.57-0.90), and poultry (RR = 0.82; 95%CI, 0.68-0.99) was significantly associated with a lower risk of cognitive impairment. A linear dose-response meta-analysis revealed that each 200-g increase in total daily dairy intake was associated with an 11% higher risk of Parkinson's disease and a 12% lower risk of cognitive impairment. Furthermore, there was a strong linear association between fish consumption and reduced risk of dementia. CONCLUSION: Dairy consumption is associated with an increased risk of Parkinson's disease, but a higher intake of fish may be associated with lower risk of neurodegenerative disease. Future well-controlled, randomized clinical trials are essential to validate the present findings. SYSTEMATIC REVIEW REGISTRATION: PROSPERO registration no. CRD42021281887.

Effects of collagen peptide supplementation on cardiovascular markers: a systematic review and meta-analysis of randomised, placebo-controlled trials.

Previous studies have advocated that collagen peptide supplementation (CPS) can positively affect cardiovascular health. However, the widespread impact of CPS on CVD-related markers is not fully resolved. Consequently, the current systematic review and meta-analysis aimed to assess the efficacy of CPS on CVD-related markers. A systematic search in the Scopus, PubMed and ISI Web of Science databases were completed to identify relevant randomised, placebo-controlled trials (RCT) published up to November 2021. Mean Differences were pooled using a random-effects model, while publication bias, sensitivity analyses and heterogeneity were assessed using previously validated methods. Twelve RCT, comprising of a total of eleven measured markers, were selected for the quantitative analysis. Pooled data revealed that CPS significantly decreased fat mass (-1·21 kg; 95 % CI: -2·13, -0·29; I2 = 0·0 %; P = 0·010) and increased fat-free mass, based on body mass percentage (1·49 %; 95 % CI: 0·57, 2·42; I2 = 0·0 %; P = 0·002). Moreover, collagen peptide supplementation led to a significant decrease in serum LDL (-4·09 mg/dl; 95 % CI: -8·13, -0·04; I2 = 93·4 %; P = 0·048) and systolic blood pressure (SBP) (-5·04 mmHg; 95 % CI: -9·22, -0·85; I2 = 98·9 %; P = 0·018). Our analysis also indicated that CPS did not affect glycemic markers. Our outcomes indicate that CPS reduces fat mass, LDL and SBP while increasing fat-free mass. Future investigations with longer CPS duration are needed to expand on our results.

The effects of cardiovascular and orthopaedic surgery on vitamin concentrations: a narrative review of the literature and mechanisms of action.

Given the rise in worldwide chronic diseases, supplemented by an aging population, the volume of global major surgeries, encompassing cardiac and orthopedic procedures is anticipated to surge significantly. Surgical trauma can be accompanied by numerous postoperative complications and metabolic changes. The present review summarized the results from studies assessing the effects of orthopedic and cardiovascular surgery on vitamin concentrations, in addition to exploring the possible mechanisms associated with changes in concentrations. Studies have revealed a potentially severe depletion in plasma/serum concentrations of numerous vitamins following these surgeries acutely. Vitamins C, D and B1 appear particularly vulnerable to significant depletions, with vitamin C and D depletions consistently transpiring into inadequate and deficient concentrations, respectively. The possible multifactorial mechanisms impacting postoperative vitamin concentrations include changes in hemodilution and vitamin utilization, redistribution, circulatory transport and absorption. For a majority of vitamins, there has been a lack of investigation into the effects of both, cardiac and orthopedic surgery. Additionally, studies were predominantly restricted to short-term postoperative investigations, primarily performed within the first postoperative week of surgery. Overall, results indicated that further examination is necessary to determine the severity and clinical significance of the possible depletions in vitamin concentrations that ensue cardiovascular and orthopedic surgery.

Nutraceuticals in mood disorders: current knowledge and future directions.

PURPOSE OF REVIEW: There is a large evidence base of clinical trials that have investigated the efficacy of a range of nutraceuticals on mood disorders. The aim of the current review is to provide an update regarding the efficacy and safety of nutraceutical agents in mood disorders and to highlight considerations for future research. RECENT FINDINGS: Nutraceuticals such as omega-3, probiotics, zinc, saffron and curcumin have been recommended as adjunctive interventions to standard treatments for people with depression, while St John's wort has been recommended as a monotherapy. In contrast, less research has been devoted to investigating the effect of nutraceuticals in bipolar disorder, with omega-3 being weakly recommended as an adjunctive to standard treatments. Although the safety profile of most nutraceuticals appears acceptable, more insight into the long-term effects within a range of cohorts is recommended. SUMMARY: There are a number of nutraceuticals that have clinical trial support for their use as either adjunctive interventions for depression; however, there is mostly limited support for their use in bipolar disorder. Further randomized controlled trials that take into consideration a number of emerging mechanisms, potential nutraceutical combinations and factors that may predict treatment response are required to inform clinical use.

Cryotherapy for oral mucositis in cancer: review of systematic reviews and meta-analysis.

BACKGROUND: One of the most common side effects of cancer treatment is oral mucositis. Although studies have shown that oral cryotherapy has a favourable effect on oral mucositis, the reliability of the results is questionable. OBJECTIVE: The goal of this umbrella review was to provide insight into the effects of oral cryotherapy against oral mucositis in patients with cancer, as well as to assess the certainty of this evidence. METHOD: Studies were searched for through PubMed, Scopus and Web of Science, with no restrictions until August 2021. The risk ratio (RR) and 95% CI for each meta-analysis were recalculated using a random-effects model, and the certainty of the evidence was judged using Grading of Recommendations Assessment, Development and Evaluation. RESULTS: Ten meta-analyses including 25 original RCTs that fit our inclusion criteria were included. The use of oral cryotherapy markedly reduced the occurrence of overall (RR 0.72, 95% CI 0.64 to 0.83, n=20 trials), moderate to severe (RR 0.60, 95% CI 0.45 to 0.80, n=16 trials) and severe oral mucositis (RR 0.48, 95% CI 0.34 to 0.67, n=16 trials), as well as average severity score of oral mucositis (standardised mean difference=-0.94, 95% CI -1.28 to -0.59, n=4 trials) in comparison to a control group; however, the certainty of evidence for all outcomes was rated very low. CONCLUSION: In patients with cancer, oral cryotherapy appears to greatly lower the severity and occurrence of oral mucositis, but, with very low certainty of evidence.

The effect of saffron supplementation on glycemic parameters: An overview of systematic reviews.

Due to the widespread use of herbal medicine and evidence pointing to the health benefits of saffron supplementation, this review was performed to evaluate the effects of saffron supplementation on glycemic parameters and lipid profiles based on previous reviews. Relevant articles were retrieved from various databases, which included PubMed, Scopus, ProQuest, Web of Science, Embase, and Cochrane until 2020, with no date restrictions. The quality of the included reviews was assessed using the Assessment of Multiple Systematic Reviews (AMSTAR) checklist. Finally, of 877 obtained articles, eight reviews meeting the inclusion criteria were included for analysis. Among the eight included reviews, seven articles were meta-analyses. In addition, one review had an average quality while seven had a good quality. A narrative description of the included reviews was performed, while a network meta-analysis was not conducted. A brief review of the results was reported according to the weighted mean difference and mean difference. Seven included reviews assessed the effects of saffron or crocin supplementation on glycemic parameters, and six examined these effects on lipid profile parameters. Almost half of the articles reported significant effects of these supplements on glycemic parameters and lipid profiles. Taken together, results suggest that saffron supplementation may improve glycemic and lipid profile parameters; however, further high-quality studies are needed to confirm the clinical efficacy of saffron on glycemic parameters and lipid profiles.

Ultra-Processed Food Consumption and Mental Health: A Systematic Review and Meta-Analysis of Observational Studies.

Since previous meta-analyses, which were limited only to depression and by a small number of studies available for inclusion at the time of publication, several additional studies have been published assessing the link between ultra-processed food consumption and depression as well as other mental disorders. We aimed to build on previously conducted reviews to synthesise and meta-analyse the contemporary evidence base and clarify the associations between the consumption of ultra-processed food and mental disorders. A total of 17 observational studies were included (n = 385,541); 15 cross-sectional and 2 prospective. Greater ultra-processed food consumption was cross-sectionally associated with increased odds of depressive and anxiety symptoms, both when these outcomes were assessed together (common mental disorder symptoms odds ratio: 1.53, 95%CI 1.43 to 1.63) as well as separately (depressive symptoms odds ratio: 1.44, 95%CI 1.14 to 1.82; and, anxiety symptoms odds ratio: 1.48, 95%CI 1.37 to 1.59). Furthermore, a meta-analysis of prospective studies demonstrated that greater ultra-processed food intake was associated with increased risk of subsequent depression (hazard ratio: 1.22, 95%CI 1.16 to 1.28). While we found evidence for associations between ultra-processed food consumption and adverse mental health, further rigorously designed prospective and experimental studies are needed to better understand causal pathways.

Brain derived neurotrophic factor in perioperative neurocognitive disorders: Current evidence and future directions.

An increase in the age of surgical patients as well as the volume of surgeries is associated with a rise in perioperative neurocognitive disorders. These disorders encompass acute delirium and longer-term cognitive dysfunctions. Brain derived neurotrophic factor (BDNF) is a neurotrophin that plays a dynamic role in a series of neurological functions including neuroplasticity, neurogenesis and synaptic regulation. Given the possible alterations to brain physiology in response to surgery, this review aims to explore the relationship between changes in central and peripheral BDNF concentrations and perioperative neurocognitive disorders. Higher levels of Brain tissue and blood BDNF have been associated with better cognitive function; however, the nature of the association between BDNF and delirium is uncertain. Preclinical models point to a significant depletion in BDNF expression and signalling within the brain post-operatively, while preliminary human studies demonstrate depletions in serum BDNF concentration after surgery. These findings suggest that the reduced BDNF concentrations may be associated with post-operative cognitive dysfunction. Thus, understanding the BDNF expression/signalling pathways may present a promising avenue for managing perioperative neurocognitive disorders symptoms. Nonetheless, given that results were primarily derived from preclinical models, it is critical for these findings to be validated in humans to confirm the relevance of this promising target.

The Effects of Dietary Advanced Glycation End-Products on Neurocognitive and Mental Disorders.

Advanced glycation end products (AGEs) are glycated proteins or lipids formed endogenously in the human body or consumed through diet. Ultra-processed foods and some culinary techniques, such as dry cooking methods, represent the main sources and drivers of dietary AGEs. Tissue accumulation of AGEs has been associated with cellular aging and implicated in various age-related diseases, including type-2 diabetes and cardiovascular disease. The current review summarizes the literature examining the associations between AGEs and neurocognitive and mental health disorders. Studies indicate that elevated circulating AGEs are cross-sectionally associated with poorer cognitive function and longitudinally increase the risk of developing dementia. Additionally, preliminary studies show that higher skin AGE accumulation may be associated with mental disorders, particularly depression and schizophrenia. Potential mechanisms underpinning the effects of AGEs include elevated oxidative stress and neuroinflammation, which are both key pathogenetic mechanisms underlying neurodegeneration and mental disorders. Decreasing dietary intake of AGEs may improve neurological and mental disorder outcomes. However, more sophisticated prospective studies and analytical approaches are required to verify directionality and the extent to which AGEs represent a mediator linking unhealthy dietary patterns with cognitive and mental disorders.

Effects of a Probiotic Formulation on Seasonal Allergic Rhinitis in Adults-A Randomized Double-Blind Placebo-Controlled Trial: The Probiotics for Hay Fever Trial.

Background: Seasonal-allergic-rhinitis (hay fever) affects approximately 4.6 million (20%) Australians each year. Hay fever manifests as runny/blocked nose and often itchy/sore/swollen eyes, with symptoms greatly impacting the quality of life. Rescue medications such as antihistamines are often needed to restore function, but they may trigger some other unwanted side effects. Probiotics have shown promise to reduce hay fever symptoms. Objective: In this randomized double-blind placebo-controlled 12-week trial, we aimed to assess the tolerability and efficacy of the probiotic formula "NC-Seasonal-Biotic" on symptoms, quality-of-life, and immunological and microbial factors. Methods: Adults, who had previously suffered from hay fever symptoms, were screened for eligibility and randomly allocated to probiotic or placebo trial powder. Treatment effectiveness was assessed by questionnaires, daily total-nasal-symptom-score, and weekly rhinoconjunctivitis quality-of-life questionnaire. Secondary outcome measures included immunological parameters such as T-cell immunity (Th1/Th2 ratio) and the stool-microbiome analysis. Tolerability was assessed weekly by the gastrointestinal symptom scale. Results: Recruitment and follow-up were challenging around the 2020/2021 hay fever season in Melbourne, Australia, due to the harsh COVID-19 restrictions and extended lockdowns. Out of the 82 adults enrolled in this study, 75% participated (n = 60), and half (n = 40) completed the 10-12-week intervention period. In the intention-to-treat analysis, no significant differences in hay fever symptoms were apparent between the groups, while quality-of-life trended toward greater improvement in the active group. Intention-to-treat analysis was confounded due to a third of all participants not completing the full 10-12-week-intervention period. Subgroup analyses of the participants (n = 40) completing the full 10-12-week study period revealed a significantly greater reduction in symptoms in the active group compared with the placebo group, including runny nose (p = 0.04) and itchy eyes (p = 0.01). Furthermore, the active group reported significant improvements in the quality-of-life, including more functionality during the day (p = 0.05), better sleep (p = 0.005), less fatigue (p = 0.04), less thirst (p = 0.007), and less irritability (p = 0.007). Immunological parameters, measured by T-helper cell ratio (Th1/Th2), improved significantly in the active group compared with the placebo group. Most microbial changes were not statistically different between the groups. The trial powder was generally well tolerated. Conclusion: Our study suggests the probiotic formula "NC-Seasonal-Biotic," taken for 10-12 weeks, as effective in reducing hay fever symptoms, such as runny nose and itchy eyes, and improved the quality-of-life and immunological parameters while being well tolerated. Clinical Trial Registration: [www.ClinicalTrials.gov], identifier [ACTRN126200 01078943].