Following the World Health Organization’s recommendation of exclusive breastfeeding to six months of age does not impact the growth of rural Gambian infants

Background: The World Health Organization (WHO) recommends exclusive breastfeeding (EBF) for the first six months of life. Objective: The objective of this study is to assess the benefit to growth of EBF to six months in a large sample of rural Gambian infants at high risk of undernutrition. Methods: Infants with growth monitoring from birth to two years of age (n=756) from the Early Nutrition and Immune Development (ENID) trial (clinical trial registry ISRCTN49285450) were categorised as exclusively breastfed if only breastmilk and no other liquids or foods were given. EBF status was entered into confounder-adjusted multilevel models to test associations with growth trajectories using more than 11,000 weight-for-age (WAZ), length-for-age (LAZ) and weight-for-length (WLZ) observations. Results: Thirty-two percent of infants were exclusively breastfed to six months. Mean age of discontinuation of EBF was 5.2 months, and growth faltering started around 3.5 months of age. Some evidence for a difference in WAZ and WHZ was found between infants who were exclusively breastfed to six months (EBF-6) and those who were not (nEBF-6), at six and 12 months of age, with EBF-6 children having a higher mean z-score. The difference in z-scores between the two groups were however small in magnitude (at six months of age: +0.147 WAZ; 95%CI: -0.001, 0.293, +0.189 WHZ; 95%CI: 0.038, 0.341). No evidence for a difference between EBF-6 and nEBF-6 infants was observed for LAZ at any time-point (6, 12 and 24 months of age). It was further found that a higher mean WLZ at three months of age was associated with a subsequent higher mean age at discontinuation of EBF, implying reverse causality in this setting (coefficient 0.060, 95%CI: 0.008, 0.120). Conclusion: This study suggest that exclusive breastfeeding to six months has limited benefit to the growth of rural Gambian infants

Adherence to EAT-Lancet dietary recommendations for health and sustainability in the Gambia

Facilitating dietary change is pivotal to improving population health, increasing food system resilience, and minimizing adverse impacts on the environment, but assessment of the current 'status-quo' and identification of bottlenecks for improvement has been lacking to date. We assessed deviation of the Gambian diet from the EAT-Lancet guidelines for healthy and sustainable diets and identified leverage points to improve nutritional and planetary health. We analysed the 2015/16 Gambian Integrated Household Survey dataset comprising food consumption data from 12 713 households. Consumption of different food groups was compared against the EAT-Lancet reference diet targets to assess deviation from the guidelines. We computed a 'sustainable and healthy diet index (SHDI)' based on deviation of different food groups from the EAT-Lancet recommendations and modelled the socio-economic and geographic determinants of households that achieved higher scores on this index, using multivariable mixed effects regression. The average Gambian diet had very low adherence to EAT-Lancet recommendations. The diet was dominated by refined grains and added sugars which exceeded the recommendations. SHDI scores for nutritionally important food groups such as fruits, vegetables, nuts, dairy, poultry, and beef and lamb were low. Household characteristics associated with higher SHDI scores included: being a female-headed household, having a relatively small household size, having a schooled head of the household, having a high wealth index, and residing in an urban settlement. Furthermore, diets reported in the dry season and households with high crop production diversity showed increased adherence to the targets. While average Gambian diets include lower amounts of food groups with harmful environmental footprint, they are also inadequate in healthy food groups and are high in sugar. There are opportunities to improve diets without increasing their environmental footprint by focusing on the substitution of refined grains by wholegrains, reducing sugar and increasing fruit and vegetables consumption

Ready-to-use food supplement, with or without arginine and citrulline, with daily chloroquine in Tanzanian children with sickle-cell disease: a double-blind, random order crossover trial

Background: Sickle cell disease increases malnutrition risk. Low arginine and nitric oxide [NO] bioavailability are implicated in sickle-related morbidity. Simple interventions are required, especially in low-income settings. We aimed to test the hypotheses: (1) supplementary arginine, citrulline and daily chloroquine increases bioavailable arginine and flow-mediated-dilatation (FMDmax%; a measure of NO-dependent endothelial function), and (2); protein energy supplementation in the form of ready-to-use supplementary-food (RUSF) improves nutritional status in children with sickle cell disease. Methods: A random-order, double-blind, cross-over trial with two four-month intervention periods (each followed by four-months wash-out) was conducted in Dar-es-Salaam, Tanzania. 119 children aged 8-12 years, naïve to hydroxyurea, were enrolled from the Muhimbili National Hospital Sickle Cohort. The random order sequence and allocation codes were generated centrally. Two formulations of RUSF (500kcal/day) were tested: ‘basic’ with weekly chloroquine (150/225mg base, depending on weight) (RUSF-b) and ‘vascular’ (RUSF-v) fortified with arginine, citrulline designed to achieve mean intakes of 0.2g/0.1g/kg/day and daily chloroquine (max 3mg base/kg/day). The primary outcomes of the comparison of the 2 RUSF formulations were mean FMDmax%, mean plasma arginine to ornithine ratio and mean plasma arginine to asymmetric-di-methylated-arginine (ADMA) ratio. The primary outcomes of the combined effect of both RUSF interventions were mean height and body mass index for age z-scores with analysis by intention to treat. Trial registration: ISRCTN74331412 Findings: 114/119 children had complete data for all reported endpoints. There was no treatment effect of RUSF-v compared to RUSF-b on the ratio of arginine to ornithine (mean within individual difference -0.09, 95% CI -0.03/0.2, p=0.12), or on FMDmax% (-1.00 95% CI -2.47/0.47, p=0.18) but the arginine:ADMA ratio was significantly increased (-0.56, 95% CI -0.81/-0.31, P<0.001). In planned analyses using random effects models to estimate the effect of each intervention compared to baseline/washout, the arginine:ADMA ratio increased following both RUSF-v or RUSF-b (+86%, p<0.001; +41%, p<0.001). Similarly, FMDmax% was higher after 2 RUSF-v (+0.92, p<0.001) but not after RUSF-b intervention (+0.39, p=0.22). Adjusted for covariates, effect estimates for FMDmax% increased: RUSF-v (+1.19, p<0.001) and RUSF-b (+0.93, p=0.008). Following either intervention (RUSF-b and RUSF-v pooled) compared to baseline/wash-outs, body-mass-index-z-score (+0.091, P=0.001) and height-for-age-z-score (+0.013, P=0.081) increased. There were 71 and 81 adverse events of which 21 and 26 were serious during intervention and washout (P=0.31) in 83 participants, 1 of whom died in the 2nd washout period. Interpretation: RUSF providing 500kcal/day results in small weight gains in children with sickle cell disease. However, RUSF even without arginine and citrulline fortification improves arginine dysregulation and may improve endothelial function. Long-term studies are required to assess if these physiological effects translate to improved clinical outcomes and better growth and development in sickle cell disease

Evidence for negative selection of gene variants that increase dependence on dietary choline in a Gambian cohort

Choline is an essential nutrient, and the amount needed in the diet is modulated by several factors. Given geographical differences in dietary choline intake and disparate frequencies of single-nucleotide polymorphisms (SNPs) in choline metabolism genes between ethnic groups, we tested the hypothesis that 3 SNPs that increase dependence on dietary choline would be under negative selection pressure in settings where choline intake is low: choline dehydrogenase (CHDH) rs12676, methylenetetrahydrofolate reductase 1 (MTHFD1) rs2236225, and phosphatidylethanolamine-N-methyltransferase (PEMT) rs12325817. Evidence of negative selection was assessed in 2 populations: one in The Gambia, West Africa, where there is historic evidence of a choline-poor diet, and the other in the United States, with a comparatively choline-rich diet. We used 2 independent methods, and confirmation of our hypothesis was sought via a comparison with SNP data from the Maasai, an East African population with a genetic background similar to that of Gambians but with a traditional diet that is higher in choline. Our results show that frequencies of SNPs known to increase dependence on dietary choline are significantly reduced in the low-choline setting of The Gambia. Our findings suggest that adequate intake levels of choline may have to be reevaluated in different ethnic groups and highlight a possible approach for identifying novel functional SNPs under the influence of dietary selective pressure

A practical guide to cross-cultural and multi-sited data collection in the biological and behavioural sciences

Researchers in the biological and behavioural sciences are increasingly conducting collaborative, multi-sited projects to address how phenomena vary across ecologies. These types of projects, however, pose additional workflow challenges beyond those typically encountered in single-sited projects. Through specific attention to cross-cultural research projects, we highlight four key aspects of multi-sited projects that must be considered during the design phase to ensure success: (1) project and team management; (2) protocol and instrument development; (3) data management and documentation; and (4) equitable and collaborative practices. Our recommendations are supported by examples from our experiences collaborating on the Evolutionary Demography of Religion project, a mixed-methods project collecting data across five countries in collaboration with research partners in each host country. To existing discourse, we contribute new recommendations around team and project management, introduce practical recommendations for exploring the validity of instruments through qualitative techniques during piloting, highlight the importance of good documentation at all steps of the project, and demonstrate how data management workflows can be strengthened through open science practices. While this project was rooted in cross-cultural human behavioural ecology and evolutionary anthropology, lessons learned from this project are applicable to multi-sited research across the biological and behavioural sciences.Host-parasite interactio

The handbook for standardised field and laboratory measurements in terrestrial climate-change experiments and observational studies

Climate change is a worldwide threat to biodiversity and ecosystem structure, functioning, and services. To understand the underlying drivers and mechanisms, and to predict the consequences for nature and people, we urgently need better understanding of the direction and magnitude of climate‐change impacts across the soil–plant–atmosphere continuum. An increasing number of climate‐change studies is creating new opportunities for meaningful and high‐quality generalisations and improved process understanding. However, significant challenges exist related to data availability and/or compatibility across studies, compromising opportunities for data re‐use, synthesis, and upscaling. Many of these challenges relate to a lack of an established “best practice” for measuring key impacts and responses. This restrains our current understanding of complex processes and mechanisms in terrestrial ecosystems related to climate change

The handbook for standardized field and laboratory measurements in terrestrial climate change experiments and observational studies (ClimEx)

Climate change is a world-wide threat to biodiversity and ecosystem structure, functioning and services. To understand the underlying drivers and mechanisms, and to predict the consequences for nature and people, we urgently need better understanding of the direction and magnitude of climate change impacts across the soil plant atmosphere continuum. An increasing number of climate change studies are creating new opportunities for meaningful and high-quality generalizations and improved process understanding. However, significant challenges exist related to data availability and/or compatibility across studies, compromising opportunities for data re-use, synthesis and upscaling. Many of these challenges relate to a lack of an established best practice for measuring key impacts and responses. This restrains our current understanding of complex processes and mechanisms in terrestrial ecosystems related to climate change. To overcome these challenges, we collected best-practice methods emerging from major ecological research networks and experiments, as synthesized by 115 experts from across a wide range of scientific disciplines. Our handbook contains guidance on the selection of response variables for different purposes, protocols for standardized measurements of 66 such response variables and advice on data management. Specifically, we recommend a minimum subset of variables that should be collected in all climate change studies to allow data re-use and synthesis, and give guidance on additional variables critical for different types of synthesis and upscaling. The goal of this community effort is to facilitate awareness of the importance and broader application of standardized methods to promote data re-use, availability, compatibility and transparency. We envision improved research practices that will increase returns on investments in individual research projects, facilitate second-order research outputs and create opportunities for collaboration across scientific communities. Ultimately, this should significantly improve the quality and impact of the science, which is required to fulfil society's needs in a changing world. © 2019 The Authors. Methods in Ecology and Evolution published by John Wiley and Sons Ltd on behalf of British Ecological Society.The authors were funded by different national and international research agencies while contributing to this work, but in the interest of the word count we are not mentioning these individually. This study was funded by the ClimMani COST Action ES1308 (2014-2018)

Gender norms and social norms: differences, similarities and why they matter in prevention science.

Two streams of theory and practice on gender equity have begun to elide. The first is work conducted to change social norms, particularly using theory that emerged from studies in social psychology. The second is work done on gender norms, emerging historically from feminist scholars working to counter gender inequality. As these two streams of work intersect, conceptual clarity is needed to understand differences and similarities between these two traditions. Increased clarity will improve efforts to address harmful norms and practices. In this article, we review similarities and differences between social and gender norms, reviewing the history of the concepts and identifying key tension points of contrast. We identified six areas of comparison that might be helpful for practitioners working for the promotion of global health as they make sense of social and gender norms. We then offer a definition of gender norms for practitioners and researchers working at the intersection between these two theories. Our definition draws from the two different streams of thought of how norms influence people's actions, acknowledging the double nature of gender norms: beliefs nested in people's minds and embedded in institutions that profoundly affect health-related behaviours and shape differential access to health services

Antibiotic-loaded bone cement and risk of infection after knee arthroplasty in high-risk patients

Background: The use of antibiotic-loaded bone cement (ALBC) in primary total knee arthroplasty (TKA) is debated. Some argue that ALBC might only be justified in high-risk patients. This study assessed the effectiveness of ALBC vs. plain bone cement (PBC) in reducing risk of revision for periprosthetic joint infection (PJI) in TKA patients considered to have a high risk of infection. Methods: Cohort study of primary TKAs in 11 national or regional arthroplasty registries from 2010 to 2020. The 1-year risk of revision for PJI in TKAs with ALBC vs. PBC among patients with high American Society of Anesthesiologists (ASA) classification, body mass index (BMI), and/or diabetes was compared. Cumulative percent revision (1 minus Kaplan-Meier) based on 685,818 TKAs and Cox regression analyses (adjusted Hazard Rate Ratios [aHRRs]) were performed for TKAs with ALBC (reference) vs. PBC restricted to the following high-risk subgroups of patients: (1) ASA ≥3 (n = 335,612 vs. 35,997), (2) BMI ≥35 (n = 278,927 vs. 24,737), (3) ASA ≥3 and BMI ≥35 (n = 99,407 vs. 11,407), (4) diabetes (n = 38,341 vs. 21,838), and (5) ASA ≥3, BMI ≥35, and diabetes (n = 3,347 vs. 4,261). Advanced distributed meta-analyses were performed to combine all aggregate data and assess 1-year risk of revision for PJI. Results: Each registry reported a 1-year cumulative percent revision of ≤1.6% for PJI following TKAs both for ALBC and PBC in all high-risk subgroups. Similar 1-year risks of revision for PJI were found in TKAs with ALBC (reference) and PBC among patients with ASA ≥3 (aHRR: 1.09; 95% CI, 0.90-1.31); BMI ≥35 (1.06; 0.54-2.12); ASA ≥3 and BMI ≥35 (1.12; 0.83-1.50); diabetes (0.95; 0.74-1.20); and ASA ≥3, BMI ≥35, and diabetes (1.40; 0.86-2.29). Conclusions and Relevance: Similar 1-year revision risk of PJI was found for TKAs with ALBC vs. PBC in high-risk patients. Confirmation of the efficacy of ALBC in high-risk TKA patients needs to be evaluated in clinical trials. Level of Evidence: Level III. See Instructions for Authors for a complete description of levels of evidence