A Comprehensive Review of Eggs,Choline, and Lutein on Cognition Across the Life-span

In 2030, one in five Americans will be older than 65 years, and with that an increase in the number of individuals who experience loss in cognitive capacity is to be expected. At the same time, nutrition within the first 1000 days postconception has been suggested to strongly influence cognitive outcomes across the life-span in humans. Eggs are a primary source of both choline and the xanthophyll carotenoid lutein in the western diet, and both have been suggested to influence cognitive function in humans. This comprehensive review critically examines the effects of eggs, choline, and lutein on cognition across the life-span. There seems to be clear scientific evidence to suggest that both choline and lutein play a vital role in brain and neurological development during the first 1000 days postconception. The extent to which higher intakes of choline have the potential to enhance or influence cognition during childhood, adulthood, and/or age-related cognitive decline needs further investigation. Emerging but consistent research suggests that lutein has the potential to influence cognition across the life-span and that sufficient intakes during mid to late adulthood may help to ward off age-related cognitive decline. Macular pigment optical density (MPOD) seems to be a reliable and consistent biomarker of brain lutein concentrations across the life-span and potentially one for clinically assessing cognitive status. This review summarizes the current peer-reviewed literature and existing gaps in research.     

A Study of the Effects of Latent Iron Deficiency on Measures of Cognition: A Pilot Randomised Controlled Trial of Iron Supplementation in Young Women

Rates of iron deficiency are high amongst healthy young women. Cognitive impairment occurs secondary to iron deficiency in infants and children, but evaluation of the impact on cognition among young women is inconsistent. The aim was to determine the suitability of the IntegNeuro test battery for assessing cognitive function in iron-deficient and iron-sufficient young women. A pilot double-blinded, placebo-controlled intervention trial was conducted in iron-deficient (serum ferritin ≤ 20 μg/L and haemoglobin > 120 g/L) and iron-sufficient young women (18–35 years). Cognitive function and haematological markers of iron status were measured at baseline and follow-up. Iron-deficient participants (n = 24) were randomised to receive placebo, 60 mg or 80 mg elemental iron daily supplements for 16 weeks. A control group of iron-sufficient participants (n = 8) was allocated to placebo. Change scores for Impulsivity and Attention were significantly greater in plasma ferritin improvers than in non-improvers (p = 0.004, p = 0.026). IntegNeuro was easy to administer and acceptable to young women. Based on the differences in Memory and Attention scores between iron-deficient participants on iron treatment and those on placebo, it was decided that between 26 and 84 participants would be required in each iron treatment group for an adequately powered extension of this pilot RCT.     

Effects of Caffeine Consumption on Attention Deficit Hyperactivity Disorder (ADHD) Treatment: A Systematic Review of Animal Studies

Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterized by a persistent pattern of inattention and/or hyperactivity-impulsivity. ADHD impairments arise from irregularities primarily in dopamine (DA) and norepinephrine (NE) circuits within the prefrontal cortex. Due to ADHD medication’s controversial side effects and high rates of diagnosis, alternative/complementary pharmacological therapeutic approaches for ADHD are needed. Although the number of publications that study the potential effects of caffeine consumption on ADHD treatment have been accumulating over the last years, and caffeine has recently been used in ADHD research in the context of animal models, an updated evidence-based systematic review on the effects of caffeine on ADHD-like symptoms in animal studies is lacking. To provide insight and value at the preclinical level, a systematic review based on PRISMA guidelines was performed for all publications available up to 1 September 2021. Caffeine treatment increases attention and improves learning, memory, and olfactory discrimination without altering blood pressure and body weight. These results are supported at the neuronal/molecular level. Nonetheless, the role of caffeine in modulating ADHD-like symptoms of hyperactivity and impulsivity is contradictory, raising discrepancies that require further clarification. Our results strengthen the hypothesis that the cognitive effects of caffeine found in animal models could be translated to human ADHD, particularly during adolescence.     

Vitamin E,Alpha-Tocopherol,and Its Effects on Depression and Anxiety: A Systematic Review and Meta-Analysis

Background: Recently, it has been discovered that anti-inflammatory and anti-oxidative pathways play a role in depression and anxiety. Lower serum levels of antioxidants, such as vitamin E, have been implicated in both depression and anxiety. Methods: This PROSPERO-registered systematic review (Reference: CRD42021260058) is reported according to PRISMA guidelines. PubMed, EMBASE, CENTRAL, PsycINFO, and CINAHL were searched from inception to June 2021. Results: Twelve studies were included in this systematic review, and nine in meta-analysis of vitamin E versus placebo. For depression, meta-analysis of 354 participants showed a standardised mean difference of –0.88 (95% CI: –1.54, –0.21; I2 = 87%) favouring vitamin E. For anxiety, meta-analysis of 306 participants showed a standardised mean difference of –0.86 (95% CI: –2.11, 0.40; I2 = 95%) favouring vitamin E. Three of the studies involved a pure comparison of vitamin E against placebo, while others included constituents such as omega-3 fatty acids. Nine of the studies were at low risk of bias, two had some concerns, and one was at high risk of bias. Conclusion: Vitamin E supplementation has shown inconclusive results in ameliorating both depression and anxiety. Containing a reassuring safety profile and low cost, future studies would be of promise, and they would benefit from both larger sample sizes and from excluding other constituents, such as omega-3 fatty acids, from experimental and comparator arms.     

Impact of Dietary Lipids on the Reverse Cholesterol Transport: What We Learned from Animal Studies

Reverse cholesterol transport (RCT) is a physiological mechanism protecting cells from an excessive accumulation of cholesterol. When this process begins in vascular macrophages, it acquires antiatherogenic properties, as has been widely demonstrated in animal models. Dietary lipids, despite representing a fundamental source of energy and exerting multiple biological functions, may induce detrimental effects on cardiovascular health. In the present review we summarize the current knowledge on the mechanisms of action of the most relevant classes of dietary lipids, such as fatty acids, sterols and liposoluble vitamins, with effects on different steps of RCT. We also provide a critical analysis of data obtained from experimental models which can serve as a valuable tool to clarify the effects of dietary lipids on cardiovascular disease.     

Influence of Vitamin D Supplementation on Mental Health in Diabetic Patients: A Systematic Review

Diabetes is associated with a number of mental health consequences, including enhanced risk of depression and anxiety, as well as decreased quality of life, and vitamin D deficiency is considered to be one of the factors that influence these outcomes in diabetic patients. The aim of the present study was to conduct a systematic review of the literature presenting the data regarding the influence of vitamin D supplementation on mental health in diabetic adults. This study was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and registered in the International Prospective Register of Systematic Reviews (PROSPERO) database (Registration number CRD42020155779). A systematic search of the PubMed and Web of Science databases was performed, and the intervention studies published until September 2021 were included in the review. The human studies were included if an adult sample of diabetic individuals received vitamin D supplementation during the intervention and its effect on any mental health aspect was assessed, but studies presenting the influence of combined supplementation of multiple nutrients were excluded. After removing duplicate records, a total of 8514 publications were screened and assessed independently by two researchers, based on their title, abstract, and full text. Finally, six studies were included in the current systematic review, and the risk of bias was evaluated using the Newcastle–Ottawa Scale (NOS). The included studies analyzed the influence of a specific dose of vitamin D, or different doses of vitamin D, or compared the results of supplementation with a specific dose of vitamin D against the placebo group. The supplementation was performed for at least 12 weeks. The mental health outcomes analyzed in these studies included health-related quality of life, depression, anxiety, stress, and general mental health status of adult diabetic patients. The results of the majority of the studies confirmed the positive influence of vitamin D supplementation on the mental health of diabetic individuals. Those studies that analyzed the influence of vitamin D supplementation on depression and anxiety established the beneficial effect of the vitamin. In some studies, the influence of vitamin D supplementation on the health-related quality of life was not considered unless combined with mindfulness training. However, it must be emphasized that different dosage regimens and intervention periods were followed in the reviewed studies, and only a small number of studies were randomized against placebo, which should be considered as a limitation of the present study. The findings of the conducted systematic review demonstrated the positive influence of vitamin D supplementation on the mental health of diabetic patients, which was proved for anxiety and depression, but in the case of health-related quality of life, the positive effect was observed only when the intervention included mindfulness training. These outcomes suggest that supplementation should be recommended to improve the vitamin D status and the mental health of patients in this group.     

Impact of mHealth Interventions on Supporting Dietary Adherence in Cardiovascular Disease: A Systematic Review

IntroductionA systematic review was conducted to determine if mobile health (mHealth) interventions, and which intervention characteristics, effectively support dietary adherence and reduce risk factors in patients with cardiovascular disease (CVD).MethodUsing 7 databases, studies involving adult participants with specific CVD diagnoses, mHealth intervention testing, and dietary adherence assessment were identified. Systematic reviews, qualitative studies, or studies testing interventions involving open dialogue between participants and health care providers or researchers were excluded. Two independent reviewers conducted screening and assessed the risk of bias.ResultsThirteen studies involved participants with prehypertension (n = 1), hypertension (n = 9), coronary artery disease (n = 2), and heart failure (n = 1). mHealth interventions in 8 studies improved dietary adherence, 4 showed mixed results, and 1 showed no improvements. Eight studies found interactive text and/or application-based mHealth intervention features effectively improved dietary adherence. One study had a low risk of bias, 2 had some concerns/moderate risk, and 10 had a high/critical or serious risk.DiscussionIn most included studies, mHealth interventions positively impacted dietary adherence for patients with CVD.Implications for Research and PracticeClinicians may recommend mHealth interventions to support nutrition education and self-management for their patients with CVD.     

Effect of Dietary or Supplemental Vitamin C Intake on Vitamin C Levels in Patients with and without Cardiovascular Disease: A Systematic Review

Atherosclerosis is a pro-oxidative and pro-inflammatory disease state, which is the underlying cause of most cardiovascular events, estimated to affect 5.2% of the Australian population. Diet, and specifically vitamin C, through its antioxidant properties can play a role in impeding the development and progression of atherosclerosis. This systematic review conducted comprehensive searches in Medline, Emcare, Scopus, PubMed, and Cochrane using key search terms for vitamin C, plasma vitamin C, supplementation, and cardiovascular disease (CVD). The results demonstrated that vitamin C supplementation resulted in a significant increase in vitamin C levels in populations with or without CVD, except for one study on the CVD population. It was also seen that the healthy population baseline and post-intervention vitamin C levels were high compared to the CVD population. However, further research is indicated for CVD population groups with varying baseline vitamin C levels, such as low baseline vitamin C, within a more representative elderly cohort in order to formulate and update vitamin C repletion guidelines.     

Impact of Maternal Nutritional Supplementation during Pregnancy and Lactation on the Infant Gut or Breastmilk Microbiota: A Systematic Review

Recent evidence indicates that maternal dietary intake, including dietary supplements, during pregnancy and lactation may alter the infant gut or breastmilk microbiota, with implications for health outcomes in both the mother and infant. To review the effects of maternal nutritional supplementation during pregnancy and lactation on the infant gut or breastmilk microbiota a systematic literature search was conducted. A total of 967 studies published until February 2020 were found, 31 were eligible and 29 randomized control trials were included in the qualitative synthesis. There were 23 studies that investigated the effects of probiotic supplementation, with the remaining studies investigating vitamin D, prebiotics or lipid-based nutrient supplements (LNS). The effects of maternal nutritional supplementation on the infant gut microbiota or breastmilk microbiota were examined in 21 and 12 studies, respectively. Maternal probiotic supplementation during pregnancy and lactation generally resulted in the probiotic colonization of the infant gut microbiota, and although most studies also reported alterations in the infant gut bacterial loads, there was limited evidence of effects on bacterial diversity. The data available show that maternal probiotic supplementation during pregnancy or lactation results in probiotic colonization of the breastmilk microbiota. There were no observed effects between probiotic supplementation and breastmilk bacterial counts of healthy women, however, administration of Lactobacillus probiotic to nursing women affected by mastitis was associated with significant reductions in breastmilk Staphylococcal loads. Maternal LNS supplementation during pregnancy and lactation increased bacterial diversity in the infant gut, whilst vitamin D and prebiotic supplementation did not alter either infant gut bacterial diversity or counts. Heterogeneity in study design precludes any firm conclusions on the effects of maternal nutritional supplementation during pregnancy and lactation on the infant gut or breastmilk microbiota, warranting further research.     

The Anti-Cancer Activity of Lycopene: A Systematic Review of Human and Animal Studies

Lycopene is a nutraceutical with health-promoting and anti-cancer activities, but due to a lack of evidence, there are no recommendations regarding its use and dosage. This review aimed to evaluate the benefits of lycopene supplementation in cancer prevention and treatment based on the results of in vivo studies. We identified 72 human and animal studies that were then analysed for endpoints such as cancer incidence, improvement in treatment outcomes, and the mechanisms of lycopene action. We concluded that the results of most of the reviewed in vivo studies confirmed the anti-cancer activities of lycopene. Most of the studies concerned prostate cancer, reflecting the number of in vitro studies. The reported mechanisms of lycopene action in vivo included regulation of oxidative and inflammatory processes, induction of apoptosis, and inhibition of cell division, angiogenesis, and metastasis formation. The predominance of particular mechanisms seemed to depend on tumour organ localisation and the local storage capacity of lycopene. Finally, there is a need to look for predictive factors to identify a population that may benefit from lycopene supplementation. The potential candidates appear to be race, single nucleotide polymorphisms in carotene-cleaving enzymes, some genetic abbreviations, and insulin-like growth factor-dependent and inflammatory diseases.     

情绪对前瞻记忆影响的研究述评

前瞻记忆是指对将来要完成的活动和事件的记忆。文章对现有的有关情绪和前瞻记忆关系文献进行归纳总结,并对未来的研究进行了展望。     

Dietary Interventions with Polyphenols in Osteoarthritis: A Systematic Review Directed from the Preclinical Data to Randomized Clinical Studies

Osteoarthritis (OA) is the most common form of arthritis and a major cause of limited functionality and thus a decrease in the quality of life of the inflicted. Given the fact that the existing pharmacological treatments lack disease-modifying properties and their use entails significant side effects, nutraceuticals with bioactive compounds constitute an interesting field of research. Polyphenols are plant-derived molecules with established anti-inflammatory and antioxidant properties that have been extensively evaluated in clinical settings and preclinical models in OA. As more knowledge is gained in the research field, an interesting approach in the management of OA is the additive and/or synergistic effects that polyphenols may have in an optimized supplement. Therefore, the aim of this review was to summarize the recent literature regarding the use of combined polyphenols in the management of OA. For that purpose, a PubMed literature survey was conducted with a focus on some preclinical osteoarthritis models and randomized clinical trials on patients with osteoarthritis from 2018 to 2021 which have evaluated the effect of combinations of polyphenol-rich extracts and purified polyphenol constituents. Data indicate that combined polyphenols may be promising for the treatment of osteoarthritis in the future, but more clinical trials with novel approaches in the identification of the in-between relationship of such constituents are needed.     

Effects of Probiotics Supplementation on Gastrointestinal Symptoms in Athletes: A Systematic Review of Randomized Controlled Trials

This study examines the effectiveness of probiotic supplementation on gastrointestinal (GI) symptoms, the gut barrier function, and inflammatory markers in athletes based on data from randomised controlled trials. Searches were conducted in PubMed, the Cochrane Library, and the Web of Science up to October 2021. The protocol for this review was registered with PROSPERO (CRD42021284938). Two reviewers independently screened the titles, abstracts, and full texts to identify articles on the influence of probiotics or symbiotics on GI symptoms, gut barrier function, and cytokines, and the quality of the studies was assessed using RoB2. Ten articles involving 822 athletes were included in this review. A single strain Lactobacillus bacteria was used in three studies, seven studies used a Lactobacillus and Bifidobacterium multi-strain cocktail, and one study used this cocktail with a prebiotic. Only slight evidence was found for a positive effect of probiotics on GI symptoms in athletes during training, exercise, and competition, so it was not possible to identify the best product for managing GI symptoms in athletes. Due to the small number of studies, it was also difficult to find a direct association between the reduced exercise-induced perturbations in cytokines, gut barrier function, and GI symptoms after probiotic supplementation.     

Ghrelin as a Biomarker of Stress: A Systematic Review and Meta-Analysis

Introduction: Ghrelin is an orexigenic hormone which favors food-seeking behavior and has been postulated to be a biomarker of stress. We conducted a systematic review and meta-analysis on the evolution of ghrelin levels following acute stress. Methods: The PubMed, Cochrane Library, Embase, and ScienceDirect databases were searched for studies reporting ghrelin levels before and after acute stress in humans. Results: We included ten studies for a total of 348 patients. Acute stress (intervention) was always in a laboratory. Acute stress was psychological (Trier Social Stress Test), physical, or mixed (cold pressure test). The overall meta-analysis demonstrated an increase in ghrelin after the stress intervention (ES = 0.21, 95CI 0.09 to 0.34) compared with baseline levels. Stratification by time demonstrated an acute increase in ghrelin levels in the five minutes immediately following the initiation of stress (0.29, 0.10 to 0.48) but without any difference after. Obese individuals had a more significant (ES = 0.51, 95CI 0.18 to 0.84) and prolonged increase in ghrelin levels for up to 45 min compared with non-obese individuals who had a significant increase only five minutes after stress. Moreover, the ghrelin levels increased in response to stress with BMI (coefficient 0.028, 0.01 to 0.49; p = 0.013) and decreased with the time after the stress intervention (coefficient -0.007, −0.014 to −0.001; p = 0.025). Conclusion: Ghrelin is a biomarker of stress, with a short-term increase following acute stress. Obese individuals have both a higher and prolonged response, emphasizing the link between obesity and stress.     

Leptin as a Biomarker of Stress: A Systematic Review and Meta-Analysis

Background: Leptin is a satiety hormone mainly produced by white adipose tissue. Decreasing levels have been described following acute stress. Objective: To conduct a systematic review and meta-analysis to determine if leptin can be a biomarker of stress, with levels decreasing following acute stress. Methods: PubMed, Cochrane Library, Embase, and ScienceDirect were searched to obtain all articles studying leptin levels after acute stress on 15 February 2021. We included articles reporting leptin levels before and after acute stress (physical or psychological) and conducted random effects meta-analysis (DerSimonian and Laird approach). We conducted Meta-regressions and sensitivity analyses after exclusion of groups outside the metafunnel. Results: We included seven articles—four cohort and three case-control studies—(28 groups) from 27,983 putative articles. Leptin levels decreased after the stress intervention (effect size = −0.34, 95%CI −0.66 to −0.02) compared with baseline levels, with a greater decrease after 60 min compared to mean decrease (−0.45, −0.89 to −0.01) and in normal weight compared to overweight individuals (−0.79, −1.38 to −0.21). There was no difference in the overweight population. Sensitivity analyses demonstrated similar results. Levels of leptin after stress decreased with sex ratio—i.e., number of men/women—(−0.924, 95%CI −1.58 to −0.27) and increased with the baseline levels of leptin (0.039, 0.01 to 0.07). Conclusions: Leptin is a biomarker of stress, with a decrease following acute stress. Normal-weight individuals and women also have a higher variation of leptin levels after stress, suggesting that leptin may have implications in obesity development in response to stress in a sex-dependent manner.     

孕期铅暴露对子代大鼠情感行为及学习记忆变化的实验研究

【目的】 探讨孕期铅暴露对子代大鼠情感行为及学习记忆能力的影响。【方法】 通过孕鼠自由饮用0.1%及0.2%醋酸铅溶液的方法建立模型,其雄性子代分别为低剂量铅暴露组(LG)及高剂量铅暴露组(HG),同时设立正常对照组(NG),每组9~12只大鼠。子代大鼠出生后30日龄分别进行旷场试验(open field test,OFT)、避暗试验(passive avoidance test,PAT)以及Morris水迷宫(Morris water maze,MWM)试验,观察各组实验动物情感行为及学习记忆能力的改变。【结果】 孕期铅暴露子代大鼠在OFT中穿格得分分值降低(36.48±7.24)(F=11.65,P<0.01),后肢性站立的次数减少(10.61±3.54)(F=9.49,P<0.01),排出粪便粒数增多(19.42±3.46)(F=7.27,P<0.01),提示孕期铅暴露可使子代大鼠情感行为受到损害(P<0.01)。在PAT中,孕期铅暴露子代大鼠犯错次数增加(10.38±1.89)(F=8.69,P<0.01)且记忆潜伏期缩短[(176.41±41.89)s](F=6.48,P<0.01),提示孕期铅暴露可使子代大鼠短期学习记忆能力受损(P<0.01)。Morris水迷宫试验发现孕期铅暴露子代大鼠搜寻站台的逃逸潜伏期明显延长(F=4.61,P<0.05),搜寻策略明显变差(χ²=41.89,P<0.01),站台区域搜寻时间缩短(F=6.32,P<0.01),穿越站台区域次数减少(F=7.13,P<0.01)。提示孕期铅暴露可使子代大鼠空间学习记忆能力受损(P<0.01)。【结论】 孕期铅暴露损害子代大鼠的情感行为和学习记忆能力。     

Dietary Potassium Intake and Risk of Diabetes: A Systematic Review and Meta-Analysis of Prospective Studies

(1) Background: Dietary potassium intake is positively associated with reduction of cardiovascular risk. Several data are available on the relationship between dietary potassium intake, diabetes risk and glucose metabolism, but with inconsistent results. Therefore, we performed a meta-analysis of the prospective studies that explored the effect of dietary potassium intake on the risk of diabetes to overcome these limitations. (2) Methods: A random-effects dose–response meta-analysis was carried out for prospective studies. A potential non-linear relation was investigated using restricted cubic splines. (3) Results: A total of seven prospective studies met the inclusion criteria. Dose–response analysis detected a non-linear relationship between dietary potassium intake and diabetes risk, with significant inverse association starting from 2900 mg/day by questionnaire and between 2000 and 5000 mg/day by urinary excretion. There was high heterogeneity among studies, but no evidence of publication bias was found. (4) Conclusions: The results of this meta-analysis indicate that habitual dietary potassium consumption is associated with risk of diabetes by a non-linear dose–response relationship. The beneficial threshold found supports the campaigns in favour of an increase in dietary potassium intake to reduce the risk of morbidity and mortality. Further studies should be carried out to explore this topic.