Nutrition Research Reviews最新文献

Autism spectrum disorder (ASD) is a neurodevelopmental disorder with significant social, communicative, and behavioral challenges, and its prevalence is increasing globally at an alarming rate. Children with ASD often have nutritional imbalances, and multiple micronutrient deficiencies. Among these, zinc (Zn²⁺) deficiency is prominent and has gained extensive scientific interest over the past few years. Zn²⁺ supports numerous proteins, including enzymes and transcription factors, and controls neurogenesis and cell differentiation. It modulates synaptic transmission and plasticity by binding to receptors, ion channels, and transporters. These interactions are crucial, as changes in these processes may contribute to cognitive and behavioral abnormalities in neurodevelopmental disorders, including ASD. Notably, mutations in genes linked to ASD result in Zn²⁺ dyshomeostasis, altering pivotal biological processes. In addition, Zn²⁺ promotes gut health by maintaining gut wall integrity, preventing inflammation and leaky gut, preventing translocation of gut bacteria and their metabolites into systemic circulation, and supporting cognitive processes via the gut–brain axis. Zn²⁺ deficiency during pregnancy alters gut microbiota composition, induces pro-inflammatory cytokine production, may affect neuronal functioning, and is associated with ASD etiology in offspring, as well as the exacerbation of autistic traits in genetically predisposed children. This review focuses on Zn²⁺ dyshomeostasis, discussing various Zn²⁺-dependent dysfunctions underlying distinct autistic phenotypes and describing recent progress in the neurobiology of individuals with ASD and animal models.

The health benefits of the long-chain omega-3 polyunsaturated fatty acids (PUFA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have been known for over 50 years and underpin the UK population recommendation to consume >450 mg EPA + DHA per day. These recommendations, last revised in 2004, are based mainly on epidemiological evidence. Much research has been conducted in the interim. Most randomised controlled trials (RCT) use doses of EPA + DHA of 840 mg/d or more. For anti-inflammatory, triacylglycerol-lowering and anti-hypertensive effects, >1.5 g EPA + DHA per day is needed. Cognitive benefits are also likely to require these higher intakes. Farmed salmon now contains considerably less EPA + DHA relative to farmed fish of 20 years ago, meaning one portion per week will no longer provide the equivalent of 450 mg EPA + DHA per day. Oily fish alone can only provide a fraction of the EPA + DHA required to meet global needs. Furthermore, there is low global oily fish consumption, with typical intakes of <200 mg EPA + DHA per day, and limited intakes in vegans and vegetarians. Therefore, there is an urgent need for affordable, acceptable, alternative EPA + DHA sources, including vegan/vegetarian friendly options, such as bio-enriched poultry, red meat and milk products; fortified foods; enriched oilseeds (for example, genetically modified Camelina sativa); algae and algal oils; and approaches which enhance endogenous EPA/DHA synthesis. In this narrative review, we suggest that current EPA + DHA intake recommendations are too low, consider EPA/DHA from a holistic health-sustainability perspective and identify research, policy and knowledge mobilisation areas which need attention.

Obesity pathophysiological conditions and obesogenic diet compounds may influence brain function and structure and, ultimately, cognitive processes. Animal models of diet-induced obesity suggest that long-term dietary high fat and/or high sugar may compromise cognitive performance through concomitant peripheral and central disturbances. Some indicated mechanisms underlying this relationship are discussed here: adiposity, dyslipidaemia, inflammatory and oxidative status, insulin resistance, hormonal imbalance, altered gut microbiota and integrity, blood–brain barrier dysfunction, apoptosis/autophagy dysregulation, mitochondrial dysfunction, vascular disturbances, cerebral protein aggregates, impaired neuroplasticity, abnormal neuronal network activity and neuronal loss. Mechanistic insights are vital for identifying potential preventive and therapeutic targets. In this sense, flavonoids have gained attention due to their abundant presence in vegetable and other natural sources, their comparatively negligible adverse effects and their capacity to cross the blood–brain barrier promptly. In recent years, interventions with flavonoid sources have proven to be efficient in restoring cognitive impairment related to obesity. Its modulatory effects occur directly and indirectly into the brain, and three fronts of action are highlighted here: (1) restoring physiological processes altered in obesity; (2) promoting additional neuroprotection to the endogenous system; and (3) improving neuroplasticity mechanisms that improve cognitive performance itself. Therefore, flavonoid consumption is a promising alternative tool for managing brain health and obesity-related cognitive impairment.

The incidence of cognitive decline is rising, leading to increased attention on the preventive role of healthy foods on brain function. Previous reviews including primarily observational studies suggested that dietary proteins may improve cognitive performance, but evidence from individual randomised controlled trials (RCT) is less consistent. Therefore, this systematic review examined the long-term effects of dietary proteins from RCT, considering both their amount and type, on cognitive performance (psychomotor speed and attention, executive function, memory and global cognition). Alterations in cerebral blood flow (CBF) - a validated brain vascular function marker - were also considered. A total of 4747 studies were identified through a systematic search, resulting in twenty-three included papers reporting effects on cognitive performance (n = 23) and CBF (n = 3). Improvements were observed in three out of the nine studies that evaluated psychomotor speed which compared a dietary protein intervention with a non-protein or lower-protein control. Of the six beneficial observations on working memory (n = 12), declarative memory (n = 10) and visuospatial memory (n = 10), five were nut interventions from three different trials. Limited studies focusing on global cognition suggested that specific target populations, namely subacute stroke or dementia, may benefit more than healthy individuals from increased dietary protein intake. From the three studies involving CBF, improvements in regional blood flow were associated with most cognitive performance outcomes. The comparative effects of different protein types warrant further investigation. Overall, this review encourages additional research into protein-rich foods or supplements which could potentially prevent or mitigate cognitive decline.

The long-chain omega-3 polyunsaturated fatty acids (LC n-3PUFA) eicosapentaenoic acid (EPA; 20:5n-3), docosapentaenoic acid (DPA, 22:5n-3) and docosahexaenoic acid (DHA; 22:6n-3) are beneficial for health. The aim of this review is to provide an overview of worldwide dietary recommendations for LC n-3PUFA across life-stages for general healthy populations from technical and scientific documents (TSD) that underpin food based dietary guidelines (FBDG) or TSD from expert groups. Using the Food and Agriculture Organization global online repository of FBDG and structured Google searches, forty-two TSD were identified for inclusion. Seventy-one percent of TSD included quantitative dietary intake recommendations which varied widely across life-stages with gaps for some groups, 62% included health messages related to LC n-3PUFA consumption, 33% discussed supplementation and 29% gave guidance on high intakes. The most frequently recommended intakes for adults were 250 mg/day EPA + DHA and 250 mg/day EPA + DHA plus an additional 100-200 mg/day DHA in pregnancy. This overview is useful for nutrition science, medical, industry and consumer communities since it identifies the recommendations available and the gaps of interest to national or international groups wishing to set dietary intake recommendations for LC n-3PUFA. Low dietary intake of LC n-3PUFA from seafood is a risk factor for suboptimal health. Intake recommendations can be challenging to achieve. Most countries for which data are available show that LC n-3PUFA intakes fail to meet recommended targets, highlighting the need for accessible, innovative, sustainable alternative EPA + DHA sources e.g. bio-enriched foods and supplements to support higher population intakes, LC n-3PUFA status and health benefits.

This systematic review examined the associations of dietary factors such as nutrients, food intake, dietary patterns and dietary biomarkers with structural and functional brain MRI biomarkers, focusing on macrostructural, microstructural, lesion and perfusion measures, and functional activity/connectivity. Articles published in English were systematically searched in PubMed, Embase and PsycInfo up to 19 July 2024. A total of thirty-eight prospective cohort studies (twenty-three cross-sectional and fifteen longitudinal analyses) and thirteen intervention studies were included. Cross-sectional analyses revealed heterogenous associations: baked fish correlated with larger hippocampal volumes (β = 0·21), while oily fish, dairy products and tofu adversely related to ventricle grade. Pro-inflammatory dietary patterns were positively associated with silent infarct risk (DII Q4 v. Q1, OR = 1·77), whereas anti-inflammatory patterns tended to favour brain preservation. Longitudinal studies demonstrated more consistent protective associations: green tea consumption (+100 mL/d) reduced hippocampal atrophy by 0·024%/year, prudent dietary patterns preserved +203 mm³ left hippocampal volume over 4 years and higher plasma carotenoids decreased medial temporal lobe loss by 0·02 cm³/year. However, null findings were common across multiple dietary factors. Interventions showed limited structural benefits (effective in only two of six studies), while polyphenol-rich supplements more consistently improved cerebral perfusion and functional connectivity. Longitudinal and intervention studies demonstrated more consistent patterns than cross-sectional analyses; however, current evidence remains limited for clinical translation. Findings from cross-sectional analyses, despite being from prospective cohorts, require careful interpretation. Further replication across diverse populations and standardised long-term studies are needed before translating these associations into clinical practice.

Malnutrition results from inadequate nutrient intake, assimilation or utilisation, negatively impacting clinical outcomes and quality of life. It likely compromises gut barrier integrity, increasing intestinal permeability (IP), which impairs nutrient absorption or utilisation and increases the risk of infections and inflammation. This systematic review aims to examine the current evidence on the association between malnutrition and IP, identifying existing research gaps. A systematic search was conducted on PubMed, Scopus and Web of Science up to June 2024. According to PECOS strategy, ‘P’ = malnourished individuals or at risk of malnutrition, assessed for intestinal permeability; ‘E’ = malnutrition or risk of malnutrition; ‘C’ = well-nourished individuals; ‘O’ = increased intestinal permeability; and ‘S’ = all study types. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist was followed, and Study Quality Assessment Tools (NIH) were used for methodological quality analysis. Sixteen studies met the inclusion criteria, with a moderate/high risk of bias. Malnourished individuals exhibited increased IP across various conditions (e.g. anorexia nervosa, cancer and liver cirrhosis) or setting (hospital and community). A wide heterogeneity was observed in malnutrition assessment tools, which consider different parameters such as body mass index, body weight loss and food intake. Similarly, diverse biomarkers/methods for assessing IP, including direct and indirect approaches, were used. Despite methodological heterogeneity, findings show an association between malnutrition and increased IP. Standardised research, including comprehensive biomarker panels, is needed to improve comparability, facilitating the development of targeted interventions for preventing malnutrition and managing its complications.

Growing evidence has linked both the onset and symptoms of various mental disorders to lifestyle factors such as diet, exercise and sleep. The link between diet and mental health, in particular in depressive disorders, has gained interest in recent years. Previous reviews assessing the link between the Mediterranean diet (MedDiet) and mental health predominantly focused on depression, whilst others failed to integrate a summary of possible underlying mechanisms related to a link between MedDiet and mental health to complement their findings. In the present review, we provide a comprehensive synthesis of evidence on the MedDiet and diverse mental health outcomes complemented by narration of the potential mechanisms involved. A literature search was conducted across MEDLINE, PsycINFO, Scopus, Cochrane library, Google Scholar, CINAHL and Embase databases. A total of 10 249 articles were found through the primary literature search and 104 articles (88 observational and 16 interventional studies) were eligible for inclusion. The MedDiet has been associated with favourable mental health outcomes in adult populations, including reduced depressive and anxiety symptoms, lower perceived stress, and improved quality of life and overall wellbeing, both in healthy individuals and those with comorbidities, across diverse geographical settings. Mechanisms involved include the antioxidant, anti-inflammatory potential of the MedDiet and its effect on gut microbiota. Further research is warranted to rigorously establish causal inferences and to guide the optimal incorporation of Mediterranean diet principles into comprehensive prevention and treatment strategies aimed at improving mental health outcomes.

Sub-Saharan Africa (SSA) is currently undergoing rapid urbanisation, a transition that is closely linked to the adoption of sedentary lifestyles and Westernised dietary habits. This shift has contributed to a substantial rise in obesity and diet-related non-communicable diseases (DR-NCDs), placing a significant strain on already burdened healthcare systems. Among the key modifiable risk factors driving this epidemiological transition are changes in dietary patterns. Western-style diets have been shown to promote inflammation and trigger metabolic and immune dysregulation, factors that underlie the development of DR-NCDs. Conversely, many Tanzanian heritage diets incorporate a diverse array of nutrient-rich foods prepared using techniques that minimise the use of oils, sweeteners and preservatives. These diets predominantly use whole grains, legumes and fruits, foods high in dietary fibre and nutraceuticals. Nutraceuticals are known to have both immunomodulatory and metabolic benefits and could potentially counteract the negative effects associated with Western-style diets. However, the limited scientific documentation of these heritage diets endangers future research into their potential health benefits. This underscores the need for targeted efforts to preserve and promote traditional dietary practices. In this review, we summarise the diversity of heritage diets from four distinct tribes in Northern Tanzania – the Maasai, Chagga, Pare and Hadzabe – who have historically exhibited low rates of DR-NCDs but are now experiencing rapid urbanisation and lifestyle changes. We briefly describe the dietary patterns of these tribes and examine the potential links between the declining usage of traditional dietary practices and the rising prevalence of DR-NCDs in Tanzania.

A major driver of the link between poor water, sanitation and hygiene (WASH) and child stunting is hypothesised to be a sub-clinical condition of the small intestine termed environmental enteric dysfunction (EED). This systematic review aimed to collate research investigating the association between biomarkers of EED and child linear growth outcomes. A systematic search of literature was conducted to identify articles that contain a measure of a domain of EED and its association with linear growth outcomes published up to 31 December 2024. Data pertaining to the measure of EED and child linear growth, as well as study characteristics, were extracted and tabulated. A total of eighty-one studies comprising 31 996 children were included, which suggested that all EED domains, including intestinal damage and repair, intestinal absorption and permeability, microbial translocation, intestinal inflammation and systemic inflammation, were associated with child linear growth. Nuances in the measurement of association were apparent and impacted the observation of significant associations. This review found that whilst the role of EED in child stunting is relatively well established, there are challenges faced in measuring biomarkers in relation to linear growth with possible ambiguities. These issues are discussed in detail to provide aid in interpretation of existing studies and to inform future studies of this kind.