Modification of tissue fatty acid composition in Murray cod (Maccullochella peelii peelii, Mitchell) resulting from a shift from vegetable oil diets to a fish oil diet.

The dynamics of fatty acid composition modifications were examined in tissues of Murray cod fed diets containing fish oil (FO), canola oil (CO) and linseed oil (LO) for a 25-week period and subsequently transferred to a FO (finishing/wash-out) diet for a further 16 weeks. At the commencement of the wash-out period, following 25 weeks of vegetable oil substitution diets, the fatty acid compositions of Murray cod fillets were reflective of the respective diets. After transfer to the FO diet, differences decreased in quantity and in numerousness, resulting in a revert to the FO fatty acid composition. Changes in percentages of the fatty acids and total accumulation in the fillet could be described by exponential equations and demonstrated that major modifications occurred in the first days of the finishing period. A dilution model was tested to predict fatty acid composition. In spite of a general reliability of the model (Y=0.9234X+0.4260, R²=0.957, P<0.001, where X is the predicted percentage of fatty acid; Y the observed percentage of fatty acid), in some instances the regression comparing observed and predicted values was markedly different from the line of equity, indicating that the rate of change was higher than predicted (i.e. Y=0.4205X+1.191, R²=0.974, P<0.001, where X is the predicted percentage of α-linolenic acid; Y the observed percentage of α-linolenic acid). Ultimately, using the coefficient of distance (D), it was shown that the fatty acid composition of fish previously fed the vegetable oil diets returned to the average variability of the fillet fatty acid composition of Murray cod after 70 or 97 days (LO and CO respectively).

Lupin kernel fiber consumption modifies fecal microbiota in healthy men as determined by rRNA gene flourescent in situ by hybridization

Background Changes in the composition of gastrointestinal microbiota by dietary interventions using pro- and prebiotics provide opportunity for improving health and preventing disease. However, the capacity of lupin kernel fiber (LKFibre), a novel legume-derived food ingredient, to act as a prebiotic and modulate the colonic microbiota in humans needed investigation.

Aim of the study The present study aimed to determine the effect of LKFibre on human intestinal microbiota by quantitative fluorescent in situ hybridization (FISH) analysis.

Design A total of 18 free-living healthy males between the ages of 24 and 64 years consumed a control diet and a LKFibre diet (containing an additional 17–30 g/day fiber beyond that of the control—incorporated into daily food items) for 28 days with a 28-day washout period in a single-blind, randomized, crossover dietary intervention design.
Methods Fecal samples were collected for 3 days towards the end of each diet and microbial populations analyzed by FISH analysis using 16S rRNA gene-based oligonucleotide probes targeting total and predominant microbial populations.

Results Significantly higher levels of Bifidobacterium spp. (P = 0.001) and significantly lower levels of the clostridia group of C. ramosum, C. spiroforme and C. cocleatum (P = 0.039) were observed on the LKFibre diet compared with the control. No significant differences between the LKFibre and the control diet were observed for total bacteria, Lactobacillus spp., the Eubacterium spp., the C. histolyticum/C. lituseburense group and the Bacteroides–Prevotella group.
Conclusions Ingestion of LKFibre stimulated colonic bifidobacteria growth, which suggests that this dietary fiber may be considered as a prebiotic and may beneficially contribute to colon health.

Socio-economic inequalities in women`s fruit and vegetable intakes: a multilevel study of individual, social and environmental mediators

Objective: This study employed a multilevel design to test the contribution of individual, social and environmental factors to mediating socio-economic status (SES) inequalities in fruit and vegetable consumption among women. Design: A cross-sectional survey was linked with objective environmental data. Setting: A community sample involving 45 neighbourhoods. Subjects: In total, 1347 women from 45 neighbourhoods provided survey data on their SES (highest education level), nutrition knowledge, health considerations related to food purchasing, and social support for healthy eating. These data were linked with objective environmental data on the density of supermarkets and fruit and vegetable outlets in local neighbourhoods. Results: Multilevel modelling showed that individual and social factors partly mediated, but did not completely explain, SES variations in fruit and vegetable consumption. Store density did not mediate the relationship of SES with fruit or vegetable consumption. Conclusions: Nutrition promotion interventions should focus on enhancing nutrition knowledge and health considerations underlying food purchasing in order to promote healthy eating, particularly among those who are socio-economically disadvantaged. Further investigation is required to identify additional potential mediators of SES–diet relationships, particularly at the environmental level.

Fruit and vegetable consumption and stroke : meta-analysis of cohort studies

Background
Increased consumption of fruit and vegetables has been shown to be associated with a reduced risk of stroke in most epidemiological studies, although the extent of the association is uncertain. We quantitatively assessed the relation between fruit and vegetable intake and incidence of stroke in a meta-analysis of cohort studies.

Methods
We searched MEDLINE, EMBASE, the Cochrane Library, and bibliographies of retrieved articles. Studies were included if they reported relative risks and corresponding 95% CIs of stroke with respect to frequency of fruit and vegetable intake.

Findings
Eight studies, consisting of nine independent cohorts, met the inclusion criteria. These groups included 257 551 individuals (4917 stroke events) with an average follow-up of 13 years. Compared with individuals who had less than three servings of fruit and vegetables per day, the pooled relative risk of stroke was 0·89 (95% CI 0·83–0·97) for those with three to five servings per day, and 0·74 (0·69–0·79) for those with more than five servings per day. Subgroup analyses showed that fruit and vegetables had a significant protective effect on both ischaemic and haemorrhagic stroke.

Interpretation
Increased fruit and vegetable intake in the range commonly consumed is associated with a reduced risk of stroke. Our results provide strong support for the recommendations to consume more than five servings of fruit and vegetables per day, which is likely to cause a major reduction in strokes.

Effects of fish oil substitution with a mix blend vegetable oil on nutrient digestibility in Murray cod, Maccullochella peelii peelii

The replacement of fish oil with vegetable based oils is a strategy which is increasingly being adopted by the aquafeed industry as an essential component to reduce the reliance on a limited supply of a natural resource, which in turn also provides cost benefits. The aim of the present investigation was to evaluate the lipid and fatty acid digestibility of a mix blend vegetable oil in juvenile Murray cod; an emerging species of increasing interest in the Australian aquaculture sector. Five semi purified experimental diets were formulated with 17% lipid originating from fish oil (FO) which was substituted in 25% increments by blended vegetable oil (VO), formulated using olive oil (12%), palm oil (43%) and linseed oil (45%) to match the major fatty acid classes of the FO.

Significant differences between the dietary treatments with regard to the lipid and individual fatty acid digestibility were recorded. This study clearly demonstrated that in Murray cod fatty acid digestibility decreases with chain length, and inversely increases relative to the degree of unsaturation. The combination of chain length, degree of unsaturation and the melting point of individual fatty acids resulted in the digestibility of PUFA > MUFA > SFA and short chain > longer chain fatty acids. Therefore, the inclusion of a mixed blend vegetable oil resulted in significantly reduced lipid digestibility in juvenile Murray cod.

Evaluation of brief dietary questions to estimate vegetable and fruit consumption - using serum carotenoids and red-cell folate

Objective To evaluate responses to self-administered brief questions regarding consumption of vegetables and fruit by comparison with blood levels of serum carotenoids and red-cell folate.

Design A cross-sectional study in which participants reported their usual intake of fruit and vegetables in servings per day, and serum levels of five carotenoids (α-carotene, β-carotene, β-cryptoxanthin, lutein/zeaxanthin and lycopene) and red-cell folate were measured. Serum carotenoid levels were determined by high-performance liquid chromatography, and red-cell folate by an automated immunoassay system.

Settings and subjects Between October and December 2000, a sample of 1598 adults aged 25 years and over, from six randomly selected urban centres in Queensland, Australia, were examined as part of a national study conducted to determine the prevalence of diabetes and associated cardiovascular risk factors.

Results Statistically significant (P<0.01) associations with vegetable and fruit intake (categorised into groups: ≤1 serving, 2–3 servings and ≥4 servings per day) were observed for α-carotene, β-carotene, β-cryptoxanthin, lutein/zeaxanthin and red-cell folate. The mean level of these carotenoids and of red-cell folate increased with increasing frequency of reported servings of vegetables and fruit, both before and after adjusting for potential confounding factors. A significant association with lycopene was observed only for vegetable intake before adjusting for confounders.

Conclusions These data indicate that brief questions may be a simple and valuable tool for monitoring vegetable and fruit intake in this population.

Investigation of plasmodiophora brassicae (clubroot disease) in vegetable brassica using arabidopsis thaliana as a model system

Clubroot, caused by Plasmodiophora brassicae, is the most devastating soil-borne disease of vegetable brassicas. It occurs all over the world and is responsible for crop losses of up to 10% every year. In Australia, the disease is being managed effectively with chemicals and cultural practices, but ideally control can be improved in the long term by the introduction of resistant cultivars. The life cycle ofP. brassicae and mode of action of plant resistance has not been fully elucidated because of the technical difficulties of working with an obligate, soil-borne plant pathogen. However, Arabidopsis thaliana, which is a host ofP. brassicae, has great potential as a model system for studying the life cycle, the infection process and development of resistance. We have developed a sand-liquid-culture system for growing Arabidopsis that allows easy observation of all life stages and, most importantly, the primary plasmodial stages within the root hair. The method was first optimised for observations of the lifecycle of the pathogen in a susceptible Arabidopsis ecotype (Col-3) where all stages of the lifecycle have now been observed and characterised. Further screening of Arabidopsis ecotypes for disease resistance has utilised one of the most virulent Australian pathotypes of brassica (ECD number 16/19/31). To date, Arabidopsis ecotype Ta-0 has shown a level of tolerance to the disease even though the roots get infected. It has been reported earlier that resistance toP. brassicae in Arabidopsis is due to one or a small number of genes. To examine changes in gene expression during the early, critical stages of infection, RNA was extracted from the susceptible and resistant ecotypes at two time points, 4 days and 17 days after inoculation. Microarray analysis will be used to investigate genome wide changes in gene expression during infection but also to identify candidate genes that may confer resistance to Australian isolates of the pathogen.

Children's fruit and vegetable intake : Associations with the neighbourhood food environment

Objective : To examine associations between availability of different types of food outlets and children's fruit and vegetable intake.
Method : Parents of 340 5–6 and 461 10–12 year-old Australian children reported how frequently their child ate 14 fruits and 13 vegetables in the last week in 2002/3. A geographic information system (GIS) was used to determine the availability of the following types of food outlets near home: greengrocers; supermarkets; convenience stores; fast food outlets; restaurants, cafés and takeaway outlets. Logistic regression analyses examined the likelihood of consuming fruit ≥ 2 times/day and vegetables ≥ 3 times/day, according to access to food outlets.
Results : Overall, 62.5% of children ate fruit ≥ 2 times/day and 46.4% ate vegetables ≥ 3 times/day. The more fast food outlets (OR = 0.82, 95%CI = 0.67–0.99) and convenience stores (OR = 0.84, 95%CI = 0.73–0.98) close to home, the lower the likelihood of consuming fruit ≥ 2 times/day. There was also an inverse association between density of convenience stores and the likelihood of consuming vegetables ≥ 3 times/day (OR = 0.84, 95%CI = 0.74–0.95). The likelihood of consuming vegetables ≥ 3 times/day was greater the farther children lived from a supermarket (OR = 1.27, 95%CI = 1.07–1.51) or a fast food outlet (OR = 1.19, 95%CI = 1.06–1.35).
Conclusion : Availability of fast food outlets and convenience stores close to home may have a negative effect on children's fruit and vegetable intake.

Family influences on children's physical activity and fruit and vegetable consumption

Background : There is evidence of a clustering of healthy dietary patterns and physical activity among young people and also of unhealthy behaviours. The identification of influences on children's health behaviors, particularly clustered health behaviors, at the time at which they develop is imperative for the design of interventions. This study examines associations between parental modelling and support and children's physical activity (PA) and consumption of fruit and vegetables (FV), and combinations of these behaviours.

Methods : In 2002/3 parents of 775 Australian children aged 10–12 years reported how frequently their child ate a variety of fruits and vegetables in the last week. Children wore accelerometers for eight days during waking hours. Parental modelling and parental support (financial and transport) were self-reported. Binary logistic and multinomial logistic regression analyses examined the likelihood of achieving ≥ 2 hours of PA per day (high PA) and of consuming ≥ 5 portions of FV per day (high FV) and combinations of these behaviors (e.g. high PA/low FV), according to parental modelling and support.

Results : Items of parental modelling and support were differentially associated with child behaviours. For example, girls whose parents reported high PA modelling had higher odds of consuming ≥ 5 portions of FV/day (OR = 1.95, 95% CI = 1.32–2.87, p < 0.001). Boys whose parents reported high financial support for snacks/fast foods had higher odds of having 'high PA/low FV' (OR = 2.0, 95% CI = 1.1–3.7).

Conclusion : Parental modelling of and support for physical activity and fruit and vegetable consumption were differentially associated with these behaviours in children across behavioural domains and with combinations of these behaviours. Promoting parents' own healthy eating and physical activity behaviours as well encouraging parental modelling and support of these behaviours in their children may be important strategies to test in future research.

Effects of alternate phases of fish oil and vegetable oil-based diets in Murray cod

Fish oil (FO)- and canola oil (CO)-based diets were regularly alternated in a daily cycle (amCO: alternation of CO in the morning and FO in the afternoon, and pmCO: alternation of FO in the morning and CO in the afternoon) or in a series of weekly cycles (2W: alternation of 2 weeks on CO and 2 weeks on FO, 4W: alternation of 4 weeks on CO and 4 weeks on FO), over a 16-week period in juvenile Murray cod (Maccullochella peelii peelii). No significant differences were observed between any of the treatments in relation to the final weight. However, fish subjected to the 2W schedule were larger (P>0.05) than all other treatments (37.2 ± 0.30 vs. 34.3 ± 0.58 in the control treatment). Fish receiving the 2W treatment had a significantly lower total net disappearance of eicosapentaenoic acid 20:5n-3 (EPA) and docosahexaenoic acid 22:6n-3 (62.1% and 24.0% respectively) compared with the control treatment (fish continuously fed a blend of 50% FO and 50% CO). Likewise, Murray cod receiving the amCO daily schedule had a significantly lower total net disappearance of EPA in comparison with the CD and pmCO treatments. These data point towards the existence of cyclical mechanisms relative to fatty acid utilization/retention.