Browsing by Author "Coad, Jane"

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Adolescent anaemia status and non-haem iron source food use at the Beddawi refugee camp in North Lebanon : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Nutritional Sciences at Massey University, Manawatū, New Zealand
(Massey University, 2022) Soukieh, Jasmine
Palestinian refugees at long-term Lebanese camps are at increased anaemia risk. Adolescent Palestinians at these camps, with their disproportionately high poverty burdens, are at particular risk, though little-to-no data are available to describe this. Anaemia in Lebanon has been attributed, largely, to inadequate intake of bioavailable iron. This may occur when a population is reliant on non-haem iron food sources to meet nutrient needs, as is often the case in long-term camp settings. No studies are currently available that describe adolescent Palestinian diets at Lebanese camps. There is also a dearth of studies exploring food preparation practices that may be harnessed to optimise iron bioavailability from consumed foods at these camps. This study used an embedded mixed-methods design to evaluate anaemia prevalence, iron source food consumption, and micronutrient dietary diversity (DDS-M) for a group of adolescent Palestinians (n = 66) at the Beddawi refugee camp in North Lebanon. The study also explored household plant-food use and preparation, with particular reference to dark leafy greens, and plant-food valuation with household food preparers (FPs). Anaemia prevalence for adolescents was 29%. Median DDS-M was 4 [IQR = 1.63, range = 2-6]. Grain-based foods were consumed by the largest proportion of adolescents (100%), followed by milk source foods (84.8%) and fruits (59.1%). Jute mallow, chicory, parsley and spinach were the dark leafy greens used by the largest proportions of households (> 80%). Household use of a subset of dark leafy greens was positively associated with adolescent DDS-M (rho = 0.31, S = 14303, p-value = 0.03). All FPs reported plant food valuation; however, FPs in households with non-anaemic adolescents related plant food valuation responses with more detailed nutrient and health rationales than FPs in households with anaemic adolescents. Lemon juice, capsicum and chilli were among foods commonly reported to be co-consumed with plant meals described by FPs. Soaking pulses ahead of use was also reported. Anaemia is a moderate public health concern for this group of adolescents, and the micronutrient content of their diets is insufficiently diverse. Increased consumption of accessible dark leafy greens and co-consumption of reported vitamin C-rich foods with non-haem iron meals, in combination with extending pulse-soaking practices to additional grains may contribute to optimising dietary and biochemical iron status for these adolescents.
Assessing the sustainability of indigenous food systems in Pacific Small Island Developing States (PSIDS) : a dissertation presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Public Health Nutrition & Food Systems at Massey University, Wellington, New Zealand
(Massey University, 2022) Vogliano, Christopher
Indigenous Peoples living in Pacific Small Island Developing States (PSIDS) who have traditionally relied on locally grown, biodiverse foods for their primary source of nutrition are now seeing the adverse impacts of changing diets and climate change. Shifts away from traditional diets towards modern, imported and ultra-processed foods are likely giving rise to noncommunicable diseases such as cardiovascular disease and Type 2 Diabetes Mellitus, which are now the leading causes of mortality. Climate change is magnifying health inequities and challenging food and nutrition security through heavier rains, longer droughts, and rising sea levels. COVID-19 has highlighted additional challenges for those living in PSIDS, exposing vulnerabilities across global food systems. Using Solomon Islands as a proxy for the broader Pacific, this thesis aims to assess PSIDS food system sustainability, including diet quality and diversity, as well as perceived food system transitions. Findings from this thesis can help strengthen discourse around promoting sustainable and resilient food systems and help achieve food and nutrition security targets set by the United Nations Sustainable Development Goals (SDGs).
Crohn's Disease and environmental factors in the New Zealand context : a thesis presented in partial fulfilment of the requirements for the degree of Doctoral of Philosophy in Nutritional Science at Massey University, Manawatū, New Zealand
(Massey University, 2023) Morton, Hannah
Background: Inflammatory bowel disease (IBD), consisting of Crohn’s disease (CD) and ulcerative colitis (UC), are lesser-known chronic diseases of the gastrointestinal tract. The causes of IBD are unknown, although research indicates an interplay of genetic, immunological, and environmental factors. The incidence and prevalence of CD in New Zealand (NZ) are among the highest worldwide, and unlike many other Western countries, evidence suggests the incidence rate is still increasing. Objective: The objective was to investigate the involvement of environmental factors in the aetiology, pathogenesis, and symptomatology of CD in NZ. Specifically, pathogenic bacterium Mycobacterium avium subspecies paratuberculosis (MAP), vitamin D, diet, and urbanisation. Methods: Patients with IBD and controls from around NZ completed a questionnaire on environmental factor exposure. Foods implicated in symptom triggering or exacerbation, the possible mechanism(s) involved, and whether vitamin D can confer protection, were investigated using an in vitro digestion method and in vitro model of the intestinal barrier. Serum vitamin D concentrations were measured and compared in patients and controls in order to explore a possible association between vitamin D and IBD. Lastly, the incidence and prevalence of IBD in the Manawatū region was determined, and the urban and rural incidence were compared. Results: Questionnaire derived data showed significant associations between CD and exposure to rural sources of microorganisms, and a major urban birthplace (≥100,000 residents), while rainwater for drinking and cooking during childhood was protective. No associations were observed between CD and MAP exposure. Over 50% of patients implicated dietary elements in symptom onset and/or exacerbation. The in vitro investigation findings suggest this may result from tight junction damage. Vitamin D concentrations did not differ between patients and controls, however, were significantly lower in CD patients that reported recent disease activity. In the Manawatū region, the mean annual incidence and 2013-point prevalence of CD were 17.7 and 250.4 per 100,000, respectively, and urban residence at diagnosis was associated with a six-fold greater IBD incidence compared to rural residence. Conclusions: The findings demonstrate that vitamin D, diet, and urbanisation are involved in CD. A greater understanding of environmental factors, especially modifiable factors, could provide opportunities for reducing CD risk, managing symptoms, or slowing disease progression.
An investigation into the interaction of the microbiome-gut-brain axis with stress : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Nutritional Science at Massey University, Manawatū, New Zealand
(Massey University, 2023) Bear, Tracey
This thesis aimed to investigate whether changes in the gut microbiota and associated biomarkers were associated with stress-induced anxiety-like and depressive-like behaviour. Two studies used the unpredictable chronic mild stress (UCMS) over 4 or 6 weeks (vs no UCMS, control) in Sprague-Dawley rats. Depressive-like behaviour was measured in female rats using the sucrose preference test, and the Porsolt swim test. Anxiety-like behaviour was measured with the light-dark box test. Faecal corticosterone, caecal microbiota (composition and organic acids), serum gut permeability (lipopolysaccharide-binding protein, LBP) and plasma inflammation (12 cytokines) markers were measured. Atypical behaviours were observed in female rats following UCMS and no depressive-like behaviours were observed. The circulating concentration of cytokines, but not plasma LBP or caecal organic acids, was higher in UCMS-exposed female rats. Relative abundance of taxa from the Clostridiales order and Desulfovibrionaceae family correlated with anxiety-like behaviours and plasma cytokine concentrations, regardless of UCMS. Studies of these atypical behaviours in female rats confirmed expected patterns of sucrose intake in the sucrose preference test and no decreased depressive-like behaviours in the Porsolt swim test with antidepressant citalopram and imipramine drugs. A further study also showed differences in baseline behaviour in male versus female rats, leading the second UCMS study to be in male rats. Increased faecal corticosterone and anxiety-like behaviours were observed in male UCMS-exposed and control rats at week 4 of UCMS compared to baseline. Plasma cytokine concentrations were higher in the UCMS group but higher faecal corticosterone concentrations and anxiety behaviours in control rats suggest that they were more stressed than treated rats. Caecal neurotransmitter concentrations did not differ between treatments nor correlate with serum neurotransmitter, cytokines or LBP concentrations or behaviour. The findings showed an association between the gut microbiota and anxiety-like behaviours, which was not stress dependent. No measured biomarkers explained the observed anxiety-like behaviours. Caecal digesta neurotransmitter profiles were dissimilar to serum profiles indicating it may not be an important influence on serum levels. Despite the atypical behavioural results following the interventions, the results still provided useful and unique information which contributes to the body of Microbiome Gut Brain Axis research.