Effect of diet, sex and age on fatty acid metabolism in broiler chickens : n-3 and n-6 PUFA

The PUFA metabolism in broiler chicken was studied through the whole body fatty acid balance method. Four dietary lipid sources (palm fat, Palm; soyabean oil, Soya; linseed oil, Lin; fish oil, Fish) were added at 3% to a basal diet containing 5% palm fat. Diets were fed to female and male birds from day 1 to either day 21 or day 42 of age. Birds fed the Lin diet showed a significantly higher 18 : 2n-6 accumulation compared with the other diets (85·2 v. 73·6% of net intake), whereas diet did not affect 18 : 3n-3 accumulation (mean 63% of net intake). Bioconversion of 18 : 2n-6 significantly decreased in the order Palm.> Lin > Soya > Fish (4·7, 3·9, 3·4 and 1% of net intake, respectively). The 18 : 3n-3 bioconversion on the Palm and Soya diets was similar and significantly higher than in broilers on the Lin diet (9·1 v. 5·8% of net intake). The β-oxidation of 18 : 2n-6 was significantly lower on the Lin diet than on the other diets (10·8 v. 23·3% of net intake), whereasβ-oxidation of 18 : 3n-3 was significantly higher on the Fish diet than on the other diets (41·5 v. 27·3% of net intake). Feeding fish oil suppressed apparent elongase and desaturase activity, whereas a higher dietary supply of 18 : 3n-3 and 18 : 2n-6 enhanced apparent elongation and desaturation activity on the PUFA involved in the n-3 and n-6 pathway, respectively. Accumulation of 18 : 2n-6 and 18 : 3n-3 increased andβ -oxidation decreased with age. Sex had a marginal effect on the PUFA metabolism.

The effect of fiscal policy on diet, obesity and chronic disease : a systematic review

Objective To assess the effect of food taxes and subsidies on diet, body weight and health through a systematic review of the literature.

Methods We searched the English-language published and grey literature for empirical and modelling studies on the effects of monetary subsidies or taxes levied on specific food products on consumption habits, body weight and chronic conditions. Empirical studies were dealing with an actual tax, while modelling studies predicted outcomes based on a hypothetical tax or subsidy.

Findings Twenty-four studies met the inclusion criteria: 13 were from the peer-reviewed literature and 11 were published on line. There were 8 empirical and 16 modelling studies. Nine studies assessed the impact of taxes on food consumption only, 5 on consumption and body weight, 4 on consumption and disease and 6 on body weight only. In general, taxes and subsidies influenced consumption in the desired direction, with larger taxes being associated with more significant changes in consumption, body weight and disease incidence. However, studies that focused on a single target food or nutrient may have overestimated the impact of taxes by failing to take into account shifts in consumption to other foods. The quality of the evidence was generally low. Almost all studies were conducted in high-income countries.

Conclusion Food taxes and subsidies have the potential to contribute to healthy consumption patterns at the population level. However, current evidence is generally of low quality and the empirical evaluation of existing taxes is a research priority, along with research into the effectiveness and differential impact of food taxes in developing countries.

Dietary patterns and diet quality : approaches to assessing complex exposures in nutrition

Dietary pattern analysis provides a practical way to characterise total diet. In contrast to single food approaches, measures of dietary patterns capture interactions between food components and assist in the development of food guidelines from a public health perspective. Two main approaches to assessing dietary patterns, multivariate statistical approach and dietary indices or scores in epidemiological studies, are assessed.

Guiding policy change to reduce diet-related disease in the Pacific

Research was undertaken in Fiji and Tonga to identify the most promising policy interventions to improve diets and non-communicable diseases. The participatory approach combined with modelling enabled evidence-informed decision-making by stakeholders. The framework developed is practical and systematic and is recommended for use in other countries in the region.

Food as a medicine : healthful oleocanthal in Australian olive oil

Oleocanthal has gained much interest as a natural anti-inflammatory phenolic component in olive oil. The studies conducted as part of this thesis demonstrate that oleocanthal is a stable olive oil phenolic with potential to be a prime health benefiting compound.

Diet high in monounsaturated fat does not have a different effect on arterial elasticity than a low-fat, high-carbohydrate diet

Objective : To compare the effects of a modified-fat diet high in monounsaturated fat, and a low-fat/high-carbohydrate diet on arterial elasticity.
Design : Randomized crossover design; each diet period was 1 month and a 2-week wash out period occurred in between.
Subjects/setting : Thirty healthy, free-living, nonsmoking men and women were recruited from the Melbourne, Australia, metropolitan region of Australia. Men were aged 35 to 55 years and postmenopausal women were aged 50 to 60 years and were not taking hormone replacement therapy. Twenty-eight subjects completed the study.
Intervention : Two diets of equal energy value: a modified-fat diet and a low-fat/high-carbohydrate diet; the modified-fat diet had 3 times more energy from monounsaturated fat.
Main outcome measures : Arterial elasticity and serum lipoprotein concentrations.
Statistical analysis : The general linear model was used to investigate overall effect and any carryover or order effects. Paired t test and the general linear model were used to compare the results from the 2 diet periods.
Results : High-density lipoprotein cholesterol concentration was significantly higher on the modified-fat diet than on the low-fat/low-carbohydrate diet. Arterial elasticity and concentrations of total cholesterol, low-density lipoprotein cholesterol, and triglycerides were not significantly different on the 2 diets.
Applications/conclusions : There is no evidence to favor a diet high in monounsaturated fat over a low-fat/high-carbohydrate diet because of an effect on arterial elasticity. Other changes in diet may be needed to cause a beneficial effect on arterial elasticity.

Arterial compliance, blood pressure, plasma leptin, and plasma lipids in women are improved with weight reduction equally with a meat-based diet and a plant-based diet

Obesity, strongly associated with the risk for coronary heart disease (CHD), is becoming increasingly prevalent. This study was designed to establish first whether systemic arterial compliance (SAC), an index of arterial function, is improved with weight loss and second, whether cardiovascular risk factors that improve with weight loss are reduced equally with lean meat or with an equivalent amount of plant protein in the diet. Thirty-six women, mostly overweight or obess, aged 40 ± 9 years, were allocated nonrandomly to a 16-week parallel-design trial of two equienergetic diets designed to lead to weight loss, with one arm of the study emphasizing red meat and the other soybeans as the major protein source. Body weight, waist and hip circumference, and plasma lipids, glucose, insulin, and leptin levels were measured, and SAC was calculated from ultrasound measurement of aortic flow velocity and aortic root driving pressure. Subjects lost weight (9% of body weight in 16 weeks) and showed decreased plasma total and low-density lipoprotein (LDL) cholesterol (12% and 14%, P < .0001, respectively), triacylglycerol (17%, P < .05), and leptin (24%, P < .01) concentrations. However, lipoprotein(a) [Lp(a)] levels did not change significantly. Mean arterial pressure (MAP) decreased 7% and SAC increased 28% (P < .001 for both). However, only the decrease in arterial pressure correlated significantly with the reduction in the waist to hip ratio (WHR), and the improvement in SAC correlated inversely with the blood pressure reduction (P < .001 for both). Further, weight loss and the metabolic benefits of weight loss occurred equally with the meat-based and plant-based diets. We conclude that moderate weight loss in women leads to a substantial reduction in the cardiovascular risk, including SAC.

Reduction in sugar-sweetened beverages is not associated with more water or diet drinks

Objective The Dutch Obesity Intervention in Teenagers (DOiT) is a school-based randomised controlled trial that was effective in decreasing the consumption of sugar-sweetened beverages among adolescents. The present study examined, using mediation analysis, whether this decrease in consumption of sugar-sweetened beverages could be explained by an increase in the consumption of water or diet drinks.

Design Participants completed a questionnaire about their beverage consumption at baseline and at 8 months (immediately post-intervention), 12- and 20-month follow-ups. A series of multi-level linear regression analyses were performed to examine water and diet drink consumption as potential mediators of the intervention effect on the consumption of sugar-sweetened beverages.

Setting Eighteen Dutch secondary schools.

Subjects A total of 747 adolescents (mean age: 12·7 years).

Results In addition to the DoiT intervention effect of a reduction in the consumption of sugar-sweetened beverages at 8 months (−284 ml/d; 95 % CI −420, −148) and 12 months (−260 ml/d; 95 % CI −360, −160), there was also a significant reduction in diet drinks at 8 months (−52 ml/d; 95 % CI −89, −16). There was no significant difference in water consumption at any follow-up. The decrease in sugar-sweetened beverage consumption could not be explained by an increase in water or diet drink consumption at any time point.

Conclusions Interventions aimed at reducing sugar-sweetened beverage consumption may be effective without changing consumption of other beverages. Reducing sugar-sweetened beverages was, however, a main message of the DOiT intervention. It is possible that a concomitant promotion of water may have resulted in a greater increase in water intake and replacement of sugar-sweetened beverages with water.

Neighbourhood-socioeconomic variation in women's diet : the role of nutrition environments

Background/Objectives: Living in socioeconomically disadvantaged neighbourhoods is associated with increased risk of a poor diet; however, the mechanisms underlying associations are not well understood. This study investigated whether selected healthy and unhealthy dietary behaviours are patterned by neighbourhood-socioeconomic disadvantage, and if so, whether features of the neighbourhood–nutrition environment explain these associations.

Subjects/Methods: A survey was completed by 1399 women from 45 neighbourhoods of varying levels of socioeconomic disadvantage in Melbourne, Australia. Survey data on fruit, vegetable and fast-food consumption were linked with data on food store locations (supermarket, greengrocer and fast-food store density and proximity) and within-store factors (in-store data on price and availability for supermarkets and greengrocers) obtained through objective audits. Multilevel regression analyses were used to examine associations of neighbourhood disadvantage with fruit, vegetable and fast-food consumption, and to test whether nutrition environment factors mediated these associations.

Results: After controlling for individual-level demographic and socioeconomic factors, neighbourhood disadvantage was associated with less vegetable consumption and more fast-food consumption, but not with fruit consumption. Some nutrition environmental factors were associated with both neighbourhood disadvantage and with diet. Nutrition environmental features did not mediate neighbourhood-disadvantage variations in vegetable or fast-food consumption.

Conclusions: Although we found poorer diets among women living in disadvantaged neighbourhoods in Melbourne, the differences were not attributable to less supportive nutrition environments in these neighbourhoods.

Diet of powerful owls Ninox strenua in inner city Melbourne parks, Victoria

Most dietary studies of Powerful Owls Ninox strenua have been from forested habitats or partially disturbed habitats on the urban fringe. The diets of single Powerful Owls roosting in two inner city parks in Melbourne, Victoria, in 2008 and 2009 were analysed. Common Brushtail Possum Trichosurus vulpecula and Common Ringtail Possum Pseudocheirus peregrinus were the only prey species recorded in the Fitzroy Gardens (occurring in equal numbers in the Owl’s diet), whereas Common Brushtail Possums and Black Rats Rattus rattus were recorded in the diet of the Flagstaff Gardens bird. This is a less diverse prey selection than recorded in the only other inner city dietary analysis for this species.

Serum levels of brain-derived neurotrophic factor in schizophrenia on a hypocaloric diet

Dietary factors influence BDNF in animal studies, but there is no comparable data in clinical populations. We examined the effect of a dietary intervention on BDNF serum levels in 67 DSM-IV schizophrenic outpatients (51 males and 16 females). Two groups were assessed in a cross-sectional study: one on a hypocaloric diet (HD) and the other not on a hypocaloric diet. Weight, height and BMI data were collected concurrently with 5-ml blood sampling of each subject. BDNF levels were measured with a sandwich-ELISA. The blood sample was obtained a minimum of one month after the exposure to dietary intervention. Serum BDNF levels were significantly higher in patients on the HD (p = 0.023). Additional research examining the interaction among patterns of nutritional food behavior and underlying physiopathology may result in insights upon which evidence-based decisions regarding dietary interventions can be made in people identified with major psychiatric disorders, such as schizophrenia.

Diet quality in bipolar disorder in a population-based sample of women

Background : Recent epidemiological evidence has indicated a role for diet quality in unipolar depressive illness. This study examined the association between diet quality and bipolar disorder (BD) in an epidemiological cohort of randomly selected, population-based women aged 20–93 years.

Methods : An a priori diet quality score was derived from food frequency questionnaire data, a factor analysis identified habitual dietary patterns and glycemic load was assessed. Mental health was assessed using the SCID-I/NP.

Results : BD was identified in 23 women and there were 691 participants with no history of psychopathology. Compared to those with no psychopathology, those with BD had a higher glycemic load (p = 0.06) and higher scores on a ‘western’ dietary factor (p = 0.03) and the ‘modern’ dietary factor (p = 0.02). For each standard deviation increase in a ‘western’ and ‘modern’ dietary pattern and glycemic load, the odds ratios for BD were increased (‘western’ OR = 1.88, 95% CI 1.33–2.65; ‘modern’ OR = 1.72, 95% CI 1.14–2.39; GL OR = 1.56, 95% CI 1.13–2.14). Conversely, a ‘traditional’ dietary pattern was associated with reduced odds for BD (OR = 0.53 95% CI 0.32–0.89) after adjustments for overall energy intake.

Limitations : The small sample size did not allow for multivariate analyses and the cross-sectional study design precludes any determinations regarding the direction of the relationships between diet quality and BD.

Conclusion : These data are largely concordant with results from dietary studies in unipolar depression. However, clinical recommendations cannot be made until the direction of the relationship between diet quality and BD is determined. Longitudinal studies are warranted.