Small Island Developing States: addressing the intersecting challenges of non-communicable diseases, food insecurity, and climate change.

Small Island Developing States (SIDS) include 37 UN member countries sharing economic, environmental, and social vulnerabilities and intractable health challenges. In over 80% of SIDS, more than one in six adults die prematurely from a non-communicable disease (NCD), with poor diet being a major factor. Complex upstream food system determinants include marginalised local food production and reliance on low nutritional quality food imports. These drivers need to be seen against colonial and post-colonial political-economic legacies as well as the environmental and climate crises that challenge local production systems. A range of policy commitments (eg, the 2023 Bridgetown Declaration on NCDs and Mental Health) highlight these complex interdependencies and call for cross-sectoral food system policies to improve food security, food sovereignty, and nutrition, including integrating measures for climate change adaptation and mitigation. Although addressing these intersecting challenges will also depend on global efforts, the unique approach of SIDS can inform other settings.

Understanding the links between human health, ecosystem health, and food systems in Small Island Developing States using stakeholder-informed causal loop diagrams.

Globalized food systems are a major driver of climate change, biodiversity loss, environmental degradation, and the increasing prevalence of overweight and obesity in society. Small Island Developing States (SIDS) are particularly sensitive to the negative effects of rapid environmental change, with many also exhibiting a heavy reliance on food imports and high burdens of nutrition-related disease, resulting in calls to (re)localize their food systems. Such a transition represents a complex challenge, with adaptation interventions in one part of the food system contingent on the success of interventions in other parts. To help address this challenge, we used group model-building techniques from the science of system dynamics to engage food system stakeholders in Caribbean and Pacific SIDS. Our aim was to understand the drivers of unhealthy and unsustainable food systems in SIDS, and the potential role that increased local food production could play in transformative adaptation. We present two causal loop diagrams (CLDs) considered helpful in designing resilience-enhancing interventions in local food systems. These CLDs represent 'dynamic hypotheses' and provide starting points that can be adapted to local contexts for identifying food system factors, understanding the interactions between them, and co-creating and implementing adaptation interventions, particularly in SIDS. The results can help guide understanding of complexity, assist in the co-creation of interventions, and reduce the risk of maladaptive consequences.

Impacts of COVID-19 on agriculture and food systems in Pacific Island countries (PICs): Evidence from communities in Fiji and Solomon Islands.

CONTEXT: COVID-19 mitigation measures including border lockdowns, social distancing, de-urbanization and restricted movements have been enforced to reduce the risks of COVID-19 arriving and spreading across PICs. To reduce the negative impacts of COVID-19 mitigation measures, governments have put in place a number of interventions to sustain food and income security. Both mitigation measures and interventions have had a number of impacts on agricultural production, food systems and dietary diversity at the national and household levels. OBJECTIVE: Our paper conducted an exploratory analysis of immediate impacts of both COVID-19 mitigation measures and interventions on households and communities in PICs. Our aim is to better understand the implications of COVID-19 for PICs and identify knowledge gaps requiring further research and policy attention. METHODS: To understand the impacts of COVID-19 mitigation measures and interventions on food systems and diets in PICs, 13 communities were studied in Fiji and Solomon Islands in July-August 2020. In these communities, 46 focus group discussions were carried out and 425 households were interviewed. Insights were also derived from a series of online discussion sessions with local experts of Pacific Island food and agricultural systems in August and September 2020. To complement these discussions, an online search was conducted for available literature. RESULTS AND CONCLUSIONS: Identified impacts include: 1) Reduced agricultural production, food availability and incomes due to a decline in local markets and loss of access to international markets; 2) Increased social conflict such as land disputes, theft of high-value crops and livestock, and environmental degradation resulting from urban-rural migration; 3) Reduced availability of seedlings, planting materials, equipment and labour in urban areas; 4) Reinvigoration of traditional food systems and local food production; and 5) Re-emergence of cultural safety networks and values, such as barter systems. Households in rural and urban communities appear to have responded positively to COVID-19 by increasing food production from home gardens, particularly root crops, vegetables and fruits. However, the limited diversity of agricultural production and decreased household incomes are reducing the already low dietary diversity score that existed pre-COVID-19 for households. SIGNIFICANCE: These findings have a number of implications for future policy and practice. Future interventions would benefit from being more inclusive of diverse partners, focusing on strengthening cultural and communal values, and taking a systemic and long-term perspective. COVID-19 has provided an opportunity to strengthen traditional food systems and re-evaluate, re-imagine and re-localize agricultural production strategies and approaches in PICs.

Pyridoxal 5' phosphate protects islets against streptozotocin-induced beta-cell dysfunction--in vitro and in vivo.

Administration of pyridoxal 5' phosphate (PLP) has demonstrated beneficial effects in the management of diabetes, albeit the mechanism(s) are not clearly understood. The present study addressed the islet-cell function(s) in streptozotocin (STZ)-induced diabetic mice both in vitro and in vivo. Primary islet cells primed with or without PLP (5 mmol/L) were treated with STZ (2 mmol/L) and were measured for cell viability, insulin secretion, free radicals and mRNA of Insulin and Pdx1. The specificity of PLP's response on insulin secretion was assessed with amino oxy acetic acid (AOAA)-PLP inhibitor. In vivo, the STZ (200 mg/kg b.w)-treated diabetic mice received 10 mmol/L PLP intraperitoneally a day before (PLP + STZ) or after (STZ + PLP) with three more doses once every 48 h. On 7, 14 and 21 d of STZ treatment, physiological parameters, islet morphology, insulin:glucagon, insulin:HSP104, and mRNA of Insulin, Glut2, Pdx1 and Reg1 were determined. In vitro, PLP protected islets against STZ-induced changes in viability, insulin secretion, prevented increase in free radical levels and normalized mRNA of Insulin and Pdx1. Further, AOAA inhibited PLP-induced insulin secretion in islets. In vivo, PLP treatment normalized STZ-induced changes in physiological parameters, circulating levels of PLP and insulin. Also, islet morphology, insulin:glucagon, insulin:HSP104 and mRNA levels of Insulin, Pdx1 and Glut2 were restored by 21 d. Although PLP treatment (pre- and post-STZ) prevented development of frank diabetes, STZ + PLP mice showed transient hyperglycemia, and increased mRNA for Reg1. The data suggest the cytoprotective vis-à-vis insulinotrophic effects of PLP against STZ-induced beta-cell dysfunction and underline its prophylactic use in the management of diabetes.

Immuolocalization of nestin in pancreatic tissue of mice at different ages.

AIM: To localize nestin positive cells (NPC) in pancreatic tissue of mice of different ages. METHODS: Paraffin sections of 6-8 mum of fixed pancreatic samples were mounted on poly-L-lysine coated slides and used for Immunolocalization using appropriate primary antibodies (Nestin, Insulin, Glucagon), followed by addition of a fluorescently labeled secondary antibody. The antigen-antibody localization was captured using a confocal microscope (Leica SP 5 series). RESULTS: In 3-6 d pups, the NPC were localized towards the periphery of the endocrine portion, as evident from immunolocalization of insulin and glucagon, while NPC were absent in the acinar portion. At 2 wk, NPC were localized in both the exocrine and endocrine portions. Interestingly, in 4-wk-old mice NPC were seen only in the endocrine portion, towards the periphery, and were colocalised with the glucagon positive cells. In the pancreas of 8- wk-old mice, the NPC were predominantly localized in the central region of the islet clusters, where immunostaining for insulin was at a maximum. CONCLUSION: We report for the first time the immunolocalization of NPC in the pancreas of mice of different ages (3 d to 8 wk) with reference to insulin and glucagon positive cells. The heterogeneous localization of the NPC observed may be of functional and developmental significance and suggest(s) that mice pancreatic tissue can be a potential source of progenitor cells. NPC from the pancreas can be isolated, proliferated and programmed to differentiate into insulin secreting cells under the appropriate microenvironment.