Inequalities in research on food environment policies: An evidence map of global evidence from 2010-2020.

BACKGROUND: There has been increasing pressure to implement policies for promoting healthy food environments worldwide. OBJECTIVE: This evidence map critically explored the breadth and nature of primary research from 2010-2020 evaluating the effectiveness, cost-effectiveness, development, and implementation of mandatory and voluntary food environment policies. METHODS: 'Real-world' evaluations of international, national and state level policies promoting healthy food environments, published between 2010 and 2020, were searched across 14 databases and two websites. We documented the policy and evaluation characteristics, including the International WCRF NOURISHING framework's policy categories and ten equity characteristics using the PROGRESS-Plus framework. Data were synthesised using descriptive statistics and visuals. RESULTS: We screened 27,958 records, of which 482 were included. Although these covered 70 countries, 81% of publications focused on only 12 countries (USA, UK, Australia, Canada, Mexico, Brazil, Chile, France, Spain, Denmark, New Zealand and South Africa). Studies from these countries employed more robust quantitative methods and included most of the evaluations of policy development, implementation, and cost-effectiveness. Few publications reported on Africa (n=12), Central and South Asia (n=5), and the Middle East (n=6) regions. Few also assessed public-private partnerships (PPPs, n=31, 6%) compared to voluntary approaches by the private sector (n=96, 20%), the public sector (n=90, 19%), and mandatory approaches (n=288, 60%). Most evaluations of PPPs were about two partnerships. Only 50% of publications assessing policy effectiveness compared outcomes between population groups stratified by an equity characteristic, and this proportion has decreased over time. CONCLUSIONS: There are striking inequities in the origin, scope and design of these studies, suggesting that research capacity and funding lies in the hands of a few expert teams worldwide. The small number of studies on PPPs questions the evidence base underlying the international push for PPPs to promote health. Policy evaluations should consider impacts on equity more consistently. PROSPERO REGISTRATION: CRD42020170963.

The effectiveness, cost-effectiveness and policy processes of regulatory, voluntary and partnership policies to improve food environments: an evidence synthesis.

Background: Dietary factors are among the largest and costliest drivers of chronic diseases in England. As a response, the government implements a range of population interventions to promote healthy diets by targeting food environments. Objectives: This study aimed to conduct a systematic review of the effectiveness, cost-effectiveness and policy process of real-world evaluations of national and state policies on improving food environments, with a focus on whether they were regulatory, voluntary or partnership approaches. Data sources: Fourteen relevant English-language databases were searched in November 2020 for studies published between 2010 and 2020. Methods: Six separate evidence reviews were conducted to assess the evidence of effectiveness, cost-effectiveness and policy processes of policies to improve food environments. Results: A total of 483 primary research evaluations and 14 evidence syntheses were included. The study reveals considerable geographic, methodological and other imbalances across the literature, with, for example, 81% of publications focusing only on 12 countries. The systematic reviews also reveal the effectiveness and cost-effectiveness of reviewed regulatory approaches designed to improve health, consumer behaviour and food environment outcomes while public-private partnerships and voluntary approaches to improve diets via reformulation, advertising and promotion restrictions or other changes to the environment were limited in their effectiveness and cost-effectiveness. The study also revealed key enabling and impeding factors across regulatory, voluntary and public-private partnership approaches. Conclusion: From the available evidence reviewed, this study finds that regulatory approaches appear most effective at improving the food environment, and voluntary agreements and partnerships have limited effectiveness. These findings should be carefully considered in future public health policy development, as should the findings of geographic imbalance in the evidence and inadequate representation of equity dimensions across the policy evaluations. We find that food policies are at times driven by factors other than the evidence and shaped by compromise and pragmatism. Food policy should be first and foremost designed and driven by the evidence of greatest effectiveness to improve food environments for healthier diets. Limitations: This was a complex evidence synthesis due to its scope and some policy evaluations may have been missed as the literature searches did not include specific policy names. The literature was limited to studies published in English from 2010 to 2020, potentially missing studies of interest. Future work: Priorities include the need for guidance for appraising risk of bias and quality of non-clinical studies, for reporting policy characteristics in evaluations, for supporting evaluations of real-world policies equitably across geographic regions, for capturing equity dimensions in policy evaluations, and for guideline development for quality and risk of bias of policy evaluations. Study registration: This study is registered as PROSPERO CRD42020170963. Funding: This award project was funded by the National Institute for Health and Care Research (NIHR) Public Health Research programme (NIHR award ref: NIHR128607) and is published in full in Public Health Research; Vol. 12, No. 8. See the NIHR Funding and Awards website for further award information.

Poor diet is a leading cause of death, globally, including in the United Kingdom. It also causes many types of illness and is one of the biggest drains on the United Kingdom National Health Service budget. Governments act in various ways to promote healthy diets by improving food environments: these are the physical and social surroundings that influence what and how much people eat. Some actions are regulated by government, for example, to control food production, marketing and promotions. Other actions are led by, or with, food businesses, making voluntary changes to the foods they produce, for example, by reducing salt content; this can be done by businesses alone or in partnership with government (referred to as 'public­private partnerships'). The six reviews of published research look at whether, and how, these actions to improve diets work, and whether they can provide value for money. Most regulations appear to be effective at supporting better diets. However, voluntary changes led by businesses had limited success. There were not many evaluations that assessed the effectiveness of public­private partnerships. Of those that did, partnerships with the food industry had limited effectiveness, resulting in largely unchanged outcomes. When looking at how these actions improve diets, we found that clear leadership, public support for the policy, the use of the best evidence and of local expertise helped with getting actions implemented. Factors that appear to make it harder to implement policy actions include a lack of evidence specific to the context, conflicting beliefs about what works, limited human or financial resources, lack of engagement by key people. Although the findings may help us to think about the ways forward to improve diets, more research is needed to understand whether actions to reduce diet-related ill health work, and provide value for money.

The influence of a copper efflux pump in Histoplasma capsulatum virulence.

During the infectious process, pathogenic microorganisms must obtain nutrients from the host in order to survive and proliferate. These nutritional sources include the metallic nutrient copper. Despite its essentiality, copper in large amounts is toxic. Host defense mechanisms use high copper poisoning as a fungicidal strategy to control infection. Transcriptional analyses showed that yeast cultured in the presence of copper or inside macrophages (24 h) had elevated expression of CRP1, a copper efflux pump, suggesting that Histoplasma capsulatum could be exposed to a high copper environment in macrophages during the innate immune stage of infection. Accordingly, macrophages cultured in high copper are more efficient in controlling H. capsulatum growth. Also, silencing of ATP7a, a copper pump that promotes the copper influx in phagosomes, increases fungal survival in macrophages. The rich copper environment faced by the fungus is not dependent on IFN-γ, since fungal CRP1 expression is induced in untreated macrophages. Appropriately, CRP1 knockdown fungal strains are more susceptible to macrophage control than wild-type yeasts. Additionally, CRP1 silencing decreases fungal burden in mice during the phase of innate immune response (4-day postinfection) and CRP1 is required for full virulence in a macrophage cell lines (J774 A.1 and RAW 264.7), as well as primary cells (BMDM). Thus, induction of fungal copper detoxifying genes during innate immunity and the attenuated virulence of CRP1-knockdown yeasts suggest that H. capsulatum is exposed to a copper-rich environment at early infection, but circumvents this condition to establish infection.

Histoplasma capsulatum Relies on Tryptophan Biosynthesis To Proliferate within the Macrophage Phagosome.

Histoplasma capsulatum yeasts reside and proliferate within the macrophage phagosome during infection. This nutrient-depleted phagosomal environment imposes challenges to Histoplasma yeasts for nutrition acquisition. Histoplasma yeasts require all 20 amino acids, which can be formed by de novo biosynthesis and/or acquired directly from the phagosomal environment. We investigated how Histoplasma obtains aromatic amino acids (i.e., phenylalanine, tyrosine, and tryptophan) within the phagosome during infection of macrophages. Depletion of key enzymes of the phenylalanine or tyrosine biosynthetic pathway neither impaired Histoplasma's ability to proliferate within macrophages nor resulted in attenuated virulence in vivo. However, loss of tryptophan biosynthesis resulted in reduced growth within macrophages and severely attenuated virulence in vivo. Together, these results indicate that phenylalanine and tyrosine, but not tryptophan, are available to Histoplasma within the macrophage phagosome. The herbicide glyphosate, which targets 5-enolpyruvylshikimate-3-phosphate synthase of the aromatic amino acid biosynthetic pathway, inhibited Histoplasma yeast growth, and this growth inhibition was partially reversed by aromatic amino acid supplementation or overexpression of ARO1. These results suggest that the aromatic amino acid biosynthetic pathway is a candidate drug target to develop novel antifungal therapeutics.

Nutritional status of school-age children and adolescents in low- and middle-income countries across seven global regions: a synthesis of scoping reviews.

OBJECTIVE: To summarise available evidence on the nutritional status of school-age children and adolescents (5-19 years) from seven global regions and on interventions implemented to improve malnutrition in this population. SETTING: Global. DESIGN: Findings were compiled from seven scoping literature reviews, including data from low- and middle-income countries within the following UNICEF-defined global regions: East Asia and Pacific; Europe and Central Asia; South Asia; West and Central Africa; Eastern and Southern Africa; Middle East and North Africa and Latin America and the Caribbean. RESULTS: A double burden of malnutrition was evident across the world regions reviewed: stunting, thinness, anaemia and other micronutrient deficiencies persisted, alongside rising overweight and obesity prevalence. Transitions towards diets increasingly high in energy-dense, processed and micronutrient-poor foods were observed. Evidence from intervention studies was limited, but suggested that providing multiple micronutrient-fortified foods or beverages at school may effectively target micronutrient deficiencies and facilitate weight gain in undernourished populations. Interventions to prevent or manage overweight and obesity were even more limited. There was minimal evidence of using novel technological approaches to engage school-age children and adolescents, or of involving them in designing interventions. CONCLUSION: The limited data available on nutrition of school-age children and adolescents are neither standardised nor comparable. Consensus on methods for assessing nutritional status and its determinants for this age group is urgently needed to set targets and monitor progress. Additionally, strategies are required to ensure that nutritious, safe and sustainable diets are available, affordable and appealing.

Mac1-Dependent Copper Sensing Promotes Histoplasma Adaptation to the Phagosome during Adaptive Immunity.

Intracellular pathogens residing within macrophage phagosomes are challenged with recognizing the phagosomal environment and appropriately responding to changing host defense strategies imposed in this organelle. One such phagocyte defense is the restriction of available copper as a form of nutritional immunity during the adaptive immune response to fungal pathogens. The intracellular fungal pathogen Histoplasma capsulatum adapts to this decreased copper through upregulation of the Ctr3 copper transporter. In this study, we show that Histoplasma recognizes the characteristic low-copper phagosomal environment of activated macrophages through the copper-dependent transcriptional regulator Mac1. Multiple cis-acting regulatory sequences in the CTR3 promoter control upregulation of CTR3 transcription under low-copper conditions, and the loss of Mac1 function prevents induction of Ctr3 under low-copper conditions. During adaptive immunity, this loss of copper sensing by Mac1 attenuates Histoplasma virulence more severely than loss of Ctr3 alone, indicating that Mac1 controls the expression of additional mechanisms important for pathogenesis. Transcriptional profiling of Histoplasma yeasts identified a small regulon of Mac1-dependent genes, with the most strongly regulated genes encoding proteins linked to copper, iron, and zinc homeostasis and defenses against reactive oxygen (iron-requiring catalase [CatB] and superoxide dismutase [Sod4]). Accordingly, the loss of Mac1 function increased sensitivity to copper and iron restriction and blocked low-copper-induced expression of extracellular catalase activity. Thus, Mac1-mediated sensing of low-copper signals to Histoplasma yeasts their residence within the activated macrophage phagosome, and in response, Histoplasma yeasts produce factors, including non-copper-dependent factors, to combat the enhanced defenses of activated macrophages. IMPORTANCE Histoplasma capsulatum is a fungal pathogen that survives and grows within host macrophages. For successful infection, Histoplasma must sense and adapt to a dynamic intracellular environment over the course of an infection. We demonstrate that the copper-dependent transcription factor, Mac1, enables Histoplasma sensing of low copper that characterizes the phagosome environment of activated macrophages. Histoplasma recognition of this state leads not only to upregulation of copper acquisition mechanisms but also to other non-copper-related pathogenesis strategies, including scavenging of other metals and detoxification of reactive oxygen produced by host cells. The limited set of genes regulated by Histoplasma Mac1 compared to those of other fungal pathogens suggests a response that has been tailored specifically for Histoplasma's life inside the phagosome. Thus, low levels of phagosomal copper serve as a signal to Histoplasma, enabling responses to the enhanced antimicrobial defenses resulting from immune activation of macrophages.

Metabolism of Gluconeogenic Substrates by an Intracellular Fungal Pathogen Circumvents Nutritional Limitations within Macrophages.

Microbial pathogens exploit host nutrients to proliferate and cause disease. Intracellular pathogens, particularly those exclusively living in the phagosome such as Histoplasma capsulatum, must adapt and acquire nutrients within the nutrient-limited phagosomal environment. In this study, we investigated which host nutrients could be utilized by Histoplasma as carbon sources to proliferate within macrophages. Histoplasma yeasts can grow on hexoses and amino acids but not fatty acids as the carbon source in vitro Transcriptional analysis and metabolism profiling showed that Histoplasma yeasts downregulate glycolysis and fatty acid utilization but upregulate gluconeogenesis within macrophages. Depletion of glycolysis or fatty acid utilization pathways does not prevent Histoplasma growth within macrophages or impair virulence in vivo However, loss of function in Pck1, the enzyme catalyzing the first committed step of gluconeogenesis, impairs Histoplasma growth within macrophages and severely attenuates virulence in vivo, indicating that Histoplasma yeasts rely on catabolism of gluconeogenic substrates (e.g., amino acids) to proliferate within macrophages.IMPORTANCEHistoplasma is a primary human fungal pathogen that survives and proliferates within host immune cells, particularly within the macrophage phagosome compartment. The phagosome compartment is a nutrient-limited environment, requiring Histoplasma yeasts to be able to assimilate available carbon sources within the phagosome to meet their nutritional needs. In this study, we showed that Histoplasma yeasts do not utilize fatty acids or hexoses for growth within macrophages. Instead, Histoplasma yeasts consume gluconeogenic substrates to proliferate in macrophages. These findings reveal the phagosome composition from a nutrient standpoint and highlight essential metabolic pathways that are required for a phagosomal pathogen to proliferate in this intracellular environment.

Flying under the radar: Histoplasma capsulatum avoidance of innate immune recognition.

The dimorphic fungal pathogen Histoplasma capsulatum takes advantage of the innate immune system, utilizing host macrophages as a proliferative niche while largely avoiding stimulation of signaling host receptors. As a result, innate immune cells are unable to control H. capsulatum on their own. Not all host phagocytes respond to H. capsulatum in the same way, with neutrophils and dendritic cells playing important roles in impeding fungal growth and initiating a protective TH1 response, respectively. Dendritic cells prime T-cell differentiation after internalization of yeasts via VLA-5 receptors and subsequent degradation of the yeasts. Dendritic cell-expressed TLR7 and TLR9 promote a type I interferon response for TH1 polarization. In contrast to dendritic cells, macrophages provide a hospitable intracellular environment. H. capsulatum yeasts enter macrophages via binding to phagocytic receptors. Simultaneously, α-glucan masks immunostimulatory cell wall ß-glucans and a secreted endoglucanase removes exposed ß-glucans to minimize recognition of yeasts by Dectin-1. This review highlights how phagocytes interact with H. capsulatum yeasts and the mechanisms H. capsulatum uses to limit the innate immune response.

Macrophage activation by IFN-γ triggers restriction of phagosomal copper from intracellular pathogens.

Copper toxicity and copper limitation can both be effective host defense mechanisms against pathogens. Tolerance of high copper by fungi makes toxicity as a defense mechanism largely ineffective against fungal pathogens. A forward genetic screen for Histoplasma capsulatum mutant yeasts unable to replicate within macrophages showed the Ctr3 copper transporter is required for intramacrophage proliferation. Ctr3 mediates copper uptake and is required for growth in low copper. Transcription of the CTR3 gene is induced by differentiation of H. capsulatum into pathogenic yeasts and by low available copper, but not decreased iron. Low expression of a CTR3 transcriptional reporter by intracellular yeasts implies that phagosomes of non-activated macrophages have moderate copper levels. This is further supported by the replication of Ctr3-deficient yeasts within the phagosome of non-activated macrophages. However, IFN-γ activation of phagocytes causes restriction of phagosomal copper as shown by upregulation of the CTR3 transcriptional reporter and by the failure of Ctr3-deficient yeasts, but not Ctr3 expressing yeasts, to proliferate within these macrophages. Accordingly, in a respiratory model of histoplasmosis, Ctr3-deficient yeasts are fully virulent during phases of the innate immune response but are attenuated after the onset of adaptive immunity. Thus, while technical limitations prevent direct measurement of phagosomal copper concentrations and copper-independent factors can influence gene expression, both the CTR3 promoter induction and the attenuation of Ctr3-deficient yeasts indicate activation of macrophages switches the phagosome from a copper-replete to a copper-depleted environment, forcing H. capsulatum reliance on Ctr3 for copper acquisition.

Characterization of the APSES-family transcriptional regulators of Histoplasma capsulatum.

The fungal APSES protein family of transcription factors is characterized by a conserved DNA-binding motif facilitating regulation of gene expression in fungal development and other biological processes. However, their functions in the thermally dimorphic fungal pathogen Histoplasma capsulatum are unexplored. Histoplasma capsulatum switches between avirulent hyphae in the environment and virulent yeasts in mammalian hosts. We identified five APSES domain-containing proteins in H. capsulatum homologous to Swi6, Mbp1, Stu1 and Xbp1 proteins and one protein found in related Ascomycetes (APSES-family protein 1; Afp1). Through transcriptional analyses and RNA interference-based functional tests we explored their roles in fungal biology and virulence. Mbp1 serves an essential role and Swi6 contributes to full yeast cell growth. Stu1 is primarily expressed in mycelia and is necessary for aerial hyphae development and conidiation. Xbp1 is the only factor enriched specifically in yeast cells. The APSES proteins do not regulate conversion of conidia into yeast and hyphal morphologies. The APSES-family transcription factors are not individually required for H. capsulatum infection of cultured macrophages or murine infection, nor do any contribute significantly to resistance to cellular stresses including cell wall perturbation, osmotic stress, oxidative stress or antifungal treatment. Further studies of the downstream genes regulated by the individual APSES factors will be helpful in revealing their functional roles in H. capsulatum biology.