Critical evaluation of cashmere nutrition experiments and suggestions for the design and conduct of successful experiments

Cashmere fibre production is an order of magnitude less than fibre production of Merino sheep or Angora goats and is more difficult to measure. Based on a comparison between cashmere experiments reporting responses to nutrition and those reporting no response, 13 design and management characteristics were identified that are related to the ability of experiments to discriminate among treatments. Methods must be adopted to reduce the variance in cashmere production within treatments, by using sufficient. animals per treatment, having enough replication to provide plenty of degrees of freedom to reduce error terms in analysis, and using pre-experimental cashmere production attributes as co-variants in analysis. It is preferable to use more productive and older goats, and goats that are used to handling, and to the conditions and feed to be used. Nutrition treatments need to produce different live weight growth curves and an appropriate control is needed such as live weight maintenance. As the raw cashmere fleece is composed primarily of hair and other contaminants, careful attention is required to measure, sample and test cashmere. Cashmere growth experiments should start by midsummer and last for at least four and preferably six months. These requirements make it more difficult for many university students to plan, undertake and complete long-term cashmere nutrition experiments without considerable management support.

Nutrition therapy in the prevention and treatment of pressure ulcers

Pressure ulcers are serious problems within hospital and aged care settings and are associated with adverse health outcomes and high treatment costs. Because of a high incidence of pressure ulcers in the health system, attention is now being directed to not just preventing, but also more effectively treating them. Nutrition plays a fundamental part in wound healing, with malnutrition, dehydration and recent weight loss identified as independent risk factors for the development of pressure ulcers. While the optimal nutrient intake to promote wound healing is unknown, increased needs for energy, protein, zinc and vitamins A, C and E have been documented. There is reasonable evidence to show that nutritional support, mostly by high-protein oral nutritional supplements, is effective in significantly reducing the incidence of pressure ulcers in at-risk patients by 25%. Intervention studies using high-protein or specialised disease-specific nutritional supplements support a trend to increased healing of established pressure ulcers. Such specialised supplements are typically based on defined amounts of arginine, vitamin C and zinc. Mechanisms by which nutritional support can aid in pressure ulcer prevention and healing are likely related to addressing macro- and/or micro-nutrient deficiencies arising from either poor oral intake or increased nutrient requirements related to the wound healing process. With much more research still to be done in this area, nutrition support appears an efficacious and costeffective adjunct to current medical and nursing approaches in the prevention and treatment of pressure ulcers.

Habitual fish consumption does not prevent a decrease in LCPUFA status in pregnant women (the Seychelles Child Development Nutrition Study)

Information on the status of long-chain polyunsaturated fatty acids (LCPUFAs) in pregnancy and breast milk in very high fish-eating populations is limited. The aim of this study was to examine dietary intake and changes in fatty acid status in a population of pregnant women in the Republic of Seychelles. Serum docosahexaenoic acid (DHA) decreased significantly between 28-week gestation and delivery (n=196). DHA status did not correlate significantly with length of gestation and was not associated with self-reported fish intake, which was high at 527 g/week. In breast milk, the ratio of DHA to arachidonic acid (AA) was consistent with those observed in other high fish-eating populations. Overall the data suggest that high exposure to LCPUFAs from habitual fish consumption does not prevent the documented decrease in LCPUFA status in pregnancy that occurs as a result of foetal accretion in the third trimester of pregnancy.

Neurodevelopmental effects of maternal nutritional status and exposure to methylmercury from eating fish during pregnancy

Fish contain nutrients that promote optimal brain growth and development but also contain methylmercury (MeHg) that can have toxic effects. The present study tested the hypothesis that the intake of selected nutrients in fish or measures of maternal nutritional status may represent important confounders when estimating the effects of prenatal methylmercury exposure on child development. The study took place in the Republic of Seychelles, an Indian Ocean archipelago where fish consumption is high. A longitudinal cohort study design was used. A total of 300 mothers were enrolled early in pregnancy. Nutrients considered to be important for brain development were measured during pregnancy along with prenatal MeHg exposure. The children were evaluated periodically to age 30 months. There were 229 children with complete outcome and covariate data for analysis. The primary endpoint was the Bayley Scales of Infant Development-II (BSID-II), administered at 9 and 30 months of age. Combinations of four secondary measures of infant cognition and memory were also given at 5, 9 and 25 months. Cohort mothers consumed an average of 537 g of fish (nine meals containing fish) per week. The average prenatal MeHg exposure was 5.9 ppm in maternal hair. The primary analysis examined the associations between MeHg, maternal nutritional measures and children's scores on the BSID-II and showed an adverse association between MeHg and the mean Psychomotor Developmental Index (PDI) score at 30 months. Secondary analyses of the association between the PDI and only MeHg alone or nutritional factors alone showed only a borderline significant association between MeHg and the PDI at 30 months and no associations with nutritional factors. One experimental measure at 5 months of age was positively associated with iodine status, but not prenatal MeHg exposure. These findings suggest a possible confounding role of maternal nutrition in studies examining associations between prenatal MeHg exposures and developmental outcomes in children.

Fish oil replacement in finfish nutrition

Unsustainable fishing practices have placed a heavy emphasis on aquaculture to meet the global shortfalls in the supply of fish and seafood, which are commonly accepted as the primary source of health-promoting essential omega-3 (n-3 highly unsaturated fatty acids). However, dietary fish oil is required for the production of omega-3-rich farmed fish and this commodity, in a vicious circle, is at present derived solely from wild fisheries. Decreasing global availability coupled with the highly variable price of this resource has forced the aquaculture industry to investigate the possibilities of alternative dietary lipid sources. This review attempts to compile all principal information available regarding the effects of fish oil replacement for the diets of farmed finfish, analysing the findings using a comparative approach among different cultured fish species. The review initially focuses on the present situation with regard to the production, availability and main nutritional characteristics of fish oil and the principal alternative lipid sources (such as vegetable oils and animal fats). Following this, the effects of fish oil replacement in finfish nutrition on feed quality, fish performance, feed efficiency, fish lipid metabolism, final eating quality and related economic aspects are presented and discussed.

Impact of front-of-pack 'traffic-light' nutrition labelling on consumer food purchases in the UK

Front-of-pack ‘traffic-light’ nutrition labelling has been widely proposed as a tool to improve public health nutrition. This study examined changes to consumer food purchases after the introduction of traffic-light labels with the aim of assessing the impact of the labels on the ‘healthiness’ of foods purchased. The study examined sales data from a major UK retailer in 2007. We analysed products in two categories (‘ready meals’ and sandwiches), investigating the percentage change in sales 4 weeks before and after traffic-light labels were introduced, and taking into account seasonality, product promotions and product life-cycle. We investigated whether changes in sales were related to the healthiness of products. All products that were not new and not on promotion immediately before or after the introduction of traffic-light labels were selected for the analysis (n = 6 for ready meals and n = 12 for sandwiches). For the selected ready-meals, sales increased (by 2.4% of category sales) in the 4 weeks after the introduction of traffic-light labels, whereas sales of the selected sandwiches did not change significantly. Critically, there was no association between changes in product sales and the healthiness of the products. This short-term study based on a small number of ready meals and sandwiches found that the introduction of a system of four traffic-light labels had no discernable effect on the relative healthiness of consumer purchases. Further research on the influence of nutrition signposting will be needed before this labelling format can be considered a promising public health intervention.

Building global alliances for public health nutrition training

The purpose of this paper is to present a review of opportunities and challenges for future progress in building intercountry, regional, and global alliances for public health nutrition training. Drawing on experiences from developing, implementing, and evaluating public health nutrition training in Australasia, Europe, and the Middle East, suggestions are provided for building a network of global training activities. Opportunities are described in areas such as standardization of course competencies and registration schemes, resource sharing, student and trainer exchange programs, and professional development. Challenges are identified and options presented for building global alliances in public health nutrition training into the future.