Dietary nitrate and diet quality: An examination of changing dietary intakes within a representative sample of Australian women

Dietary nitrate is increasingly linked to a variety of beneficial health outcomes. Our purpose was to estimate dietary nitrate consumption and identify key dietary changes which have occurred over time within a representative sample of Australian women. Women from the 1946–1951 cohort of the Australian Longitudinal Study on Women’s Health with complete food frequency questionnaire data for both 2001 and 2013 were included for analysis. Dietary nitrate intakes were calculated using key published nitrate databases. Diet quality scores including the Australian Recommended Food Score, the Mediterranean Diet Score and the Nutrient Rich Foods Index were calculated along with food group serves as per the Australian Dietary Guidelines. Wilcoxon matched pairs tests were used to test for change in dietary intakes and Spearman’s correlations were used to examine associations. In our sample of 8161 Australian women, dietary nitrate intakes were on average 65–70 mg/day, and we detected a significant increase in dietary nitrate consumption over time (+6.57 mg/day). Vegetables were the primary source of dietary nitrate (81–83%), in particular lettuce (26%), spinach (14–20%), beetroot (10–11%), and celery (7–8%) contributed primarily to vegetable nitrate intakes. Further, increased dietary nitrate intakes were associated with improved diet quality scores (r = 0.3, p \u3c 0.0001). Although there is emerging evidence indicating that higher habitual dietary nitrate intakes are associated with reduced morbidity and mortality, future work in this area should consider how dietary nitrate within the context of overall diet quality can facilitate health to ensure consistent public health messages are conveyed

Disparities exist between National food group recommendations and the dietary intakes of women

<p>Abstract</p> <p>Background</p> <p>Preconception and pregnancy dietary intakes can influence the health of future generations. In this study we compared the food intakes of reproductive-aged women by pregnancy status, to current Australian recommendations.</p> <p>Methods</p> <p>Data are from the Australian Longitudinal Study on Women's Health, younger cohort aged 25-30 years in 2003, with self-reported status as pregnant (n = 606), trying to conceive (n = 454), given birth in the last 12 months (n = 829) or other (n = 5597). Diet was assessed using a validated 74-item food frequency questionnaire. Food group servings and nutrient intakes were compared to the Australian Guide to Healthy Eating (AGHE) and Australian Nutrient Reference Values (NRVs).</p> <p>Results</p> <p>No women met all AGHE food group recommendations. Highest adherence rates [mean (95% CI) servings/day] were for meat [85%, 1.9(1.8-1.9)], fruit [44%, 2.1(2.1-2.2)] and dairy [35%, 1.8(1.8-1.9)], with < 14% meeting remaining recommendations. Women who achieved NRVs (folate, iron, calcium, zinc, fibre) for pregnancy, breastfeeding and adult life stages were 1.5%, 3.3% and 13.7%, respectively. Compared to AGHE, women consumed more servings of fruit (4.9 vs 4.0;<it>P </it>= 0.034) and dairy (3.4 vs 2.0;<it>P </it>= 0.006) to achieve pregnancy NRVs; more dairy (2.9 vs 2.0;<it>P </it>= 0.001), less fruit (3.9 vs 5.0;<it>P </it>< .001) and vegetables (3.4 vs 7.0;<it>P </it>< .001) to achieve breastfeeding NRVs; more fruit (3.6 vs 3.0;<it>P </it>< .001), dairy (2.5 vs 2.0;<it>P </it>< .001), meat (1.8 vs 1.5;<it>P </it>= 0.015), less vegetables (3.6 vs 5.0;<it>P </it>< .001) to achieve adult NRVs.</p> <p>Conclusions</p> <p>The AGHE does not align with contemporary diets of Australian women or enable them to meet all NRVs. Current tools to guide food consumption by women during pregnancy require revision.</p

Increasing dietetic referrals: perceptions of general practitioners, practice nurses and dietitians

Aim: To examine Australian private practice dietitians' relationships with general practitioners and practice nurses as a factor that influences dietetic referrals. Methods: Semistructured telephone interviews and an online survey were conducted with Australian private practice dietitians (n = 52 and n = 90, respectively) between April and May 2008. Semistructured questionnaires were conducted with general practitioners (n = 11) and practice nurses (n = 12) from the 'GP Access' Division of General Practice between March and July 2007. Results: General practitioners' relationships with dietitians were believed to be the primary influencing factor on referral, provided by 81% of survey dietitians and 25% of interview dietitians. The most common means of initially forming relationships with general practitioners were face-to-face introduction (48%) and introductory letters (37%). Patient feedback via letter, fax or email was the most popular method of maintaining relationships with general practitioners (77%). Meeting with general practitioners in person was believed to be the most effective activity in building relationships with general practitioners and increasing referral rates (42%). Referral was made easier for general practitioners by providing paper (37%) or electronic (19%) referral forms and contact details (19%). The majority of general practitioners and dietitians believed that the 'Allied Health Services Under Medicare' made it easier to refer to a dietitian. Conclusions: Dietetic referrals can be encouraged through good relationships between general practitioners, practice nurses and dietitians. Private practice dietitians would benefit from cultivating relationships with general practitioners and practice nurses through personal contact and providing good patient feedback

Oxidative stress and antioxidants in athletes undertaking regular exercise training

Exercise has been shown to increase the production of reactive oxygen species to a point that can exceed antioxidant defenses to cause oxidative stress. Dietary intake of antioxidants, physical activity levels, various antioxidants and oxidative stress markers were examined in 20 exercise-trained "athletes" and 20 age- and sex-matched sedentary "controls." Plasma F₂-isoprostanes, antioxidant enzyme activities, and uric acid levels were similar in athletes and sedentary controls. Plasma α-tocopherol and β-carotene were higher in athletes compared with sedentary controls. Total antioxidant capacity tended to be lower in athletes, with a significant difference between male athletes and male controls. Dietary intakes of antioxidants were also similar between groups and well above recommended dietary intakes for Australians. These findings suggest that athletes who consume a diet rich in antioxidants have elevated plasma α-tocopherol and β-carotene that were likely to be brought about by adaptive processes resulting from regular exercise

Investigation of the association between dietary intake, disease severity and airway inflammation in asthma

Background and objective: Dietary intake is an important modifiable risk factor for asthma and may be related to disease severity and inflammation, through the effects of intake of anti-oxidant-rich foods and pro-inflammatory nutrients. This study aimed to examine dietary intake in asthma in relation to asthma severity, lung function, inhaled corticosteroid use, leptin levels and inflammation. Methods: Food frequency questionnaires, spirometry and hypertonic saline challenge were completed by 137 stable asthmatics and 65 healthy controls. Plasma leptin was analysed by immunoassay. Induced sputum differential cell counts were determined. Results: Subjects with severe persistent asthma consumed more fat and less fibre as compared with healthy controls (odds ratio 1.04 (95% confidence interval: 1.01–1.07), P = 0.014) (odds ratio 0.94 (95% confidence interval: 0.90–0.99), P = 0.018). Among asthmatics, higher fat and lower fibre intakes were associated with lower forced expiratory volume in 1 s and airway eosinophilia. Leptin levels were increased in both male and female asthmatics as compared with healthy controls. No association existed among asthmatics between corticosteroid use and dietary intake. Conclusions: It was found that asthmatics within the subgroup of severe persistent asthma have a different pattern of dietary intake as compared with healthy controls, which was associated with lower lung function and increased airway inflammation

Breakfast Cereal Consumption and Obesity Risk amongst the Mid-Age Cohort of the Australian Longitudinal Study on Women’s Health

Obesity affects 27.5% of Australian women. Breakfast cereal consumption has been proposed to be protective against obesity. This study investigated the association of breakfast cereal consumption with the risk of developing obesity (Body Mass Index (BMI) ≥ 30 kg/m2) over 12 years among mid-age participants in the Australian Longitudinal Study on Women’s Health (ALSWH). Dietary data were obtained at S3 and obesity incidence at S4–S7. Women were excluded if: dietary data were incomplete, energy intake was &lt;4500 or &gt;20,000 kJ/day, or they reported being overweight or obese at S3. Logistic regressions with discrete time survival analysis investigated the association between breakfast cereal intake and incident obesity and were adjusted for: area of residency, income, smoking, physical activity, hypertension, dietary intakes and a discrete measure of time. There were 308 incident cases of obesity. Any breakfast cereal intake was not associated with incident obesity (Odds Ratio (OR): 0.92; p = 0.68). Oat-based cereal (OR: 0.71; p = 0.01), muesli (OR: 0.57; p = 0.00) and All-Bran (OR: 0.62; p = 0.01) intakes were associated with a significant reduction in obesity risk. Among this cohort, muesli on its own, or as part of oat-based cereals, and All-Bran, were associated with a reduction in obesity. This effect may be due to particular characteristics of these cereal eaters, but the relationship warrants further investigation

Soluble Fibre Meal Challenge Reduces Airway Inflammation and Expression of GPR43 and GPR41 in Asthma

Short chain fatty acids (SCFAs) are produced following the fermentation of soluble fibre by gut bacteria. In animal models, both dietary fibre and SCFAs have demonstrated anti-inflammatory effects via the activation of free fatty acid receptors, such as G protein-coupled receptor 41 and 43 (GPR41 and GPR43). This pilot study examined the acute effect of a single dose of soluble fibre on airway inflammation—including changes in gene expression of free fatty acid receptors—in asthma. Adults with stable asthma consumed a soluble fibre meal (n = 17) containing 3.5 g inulin and probiotics, or a control meal (n = 12) of simple carbohydrates. Exhaled nitric oxide (eNO) was measured and induced sputum was collected at 0 and 4 h for differential cell counts, measurement of interleukin-8 (IL-8) protein concentration, and GPR41 and GPR43 gene expression. At 4 h after meal consumption, airway inflammation biomarkers, including sputum total cell count, neutrophils, macrophages, lymphocytes, sputum IL-8, and eNO significantly decreased compared to baseline in the soluble fibre group only. This corresponded with upregulated GPR41 and GPR43 sputum gene expression and improved lung function in the soluble fibre group alone. Soluble fibre has acute anti-inflammatory effects in asthmatic airways. Long-term effects of soluble fibre as an anti-inflammatory therapy in asthma warrants further investigation

The Impact of Meal Dietary Inflammatory Index on Exercise-Induced Changes in Airway Inflammation in Adults with Asthma

Research suggests exercise may reduce eosinophilic airway inflammation in adults with asthma. The Dietary Inflammatory Index (DII®) quantifies the inflammatory potential of the diet and has been associated with asthma outcomes. This study aimed to determine whether the DII of a meal consumed either before or after exercise influences exercise-induced changes in airway inflammation. A total of 56 adults with asthma were randomised to (1) 30–45 min moderate–vigorous exercise, or (2) a control group. Participants consumed self-selected meals, two hours pre- and two hours post-intervention. Energy-adjusted DII (E-DIITM) was determined for each meal, with meals then characterised as “anti-inflammatory” or “pro-inflammatory” according to median DII. Induced sputum cell counts were measured pre- and four hours post-intervention. Participants consuming an anti-inflammatory meal two hours post-exercise had a decrease in sputum %eosinophils (−0.5 (−2.0, 0.3)%) compared with participants who consumed a pro-inflammatory meal two hours post-exercise (0.5 (0, 3.0)%, p = 0.009). There was a positive correlation between the E-DII score of the post-exercise meal and change in sputum %eosinophils (rs = 0.478, p = 0.008). The E-DII score of the meal consumed two hours pre-exercise had no effect on sputum %eosinophils (p = 0.523). This study suggests an anti-inflammatory meal two hours post-exercise augments exercise-induced improvements in eosinophilic airway inflammation in adults with asthma

Difference in perceived knowledge, confidence and attitudes between dietitians and other health professionals in the provision of weight management advice

Aim: The aim of this analysis is to establish if dietitians have the knowledge, skills and attitude to provide support to other health professional (HP) groups in the provision of weight management advice to overweight/obese patients. Methods: A secondary data analysis of a cross-sectional survey of HPs was undertaken to perform a gap analysis with regard to practices, knowledge, confidence and attitudes in the provision of weight management advice. Survey responses and additional measures (practice, knowledge, confidence and attitude scores) were compared between dietitians and other HPs. Descriptive statistics were undertaken, and differences between group x² tests were performed for nominal data and the Wilcoxon rank sum test for ordinal and non-parametric data. Results: About 100% of dietitians had received initial weight management training and 85% had participated in professional development training, compared with 18 and 19% of HPs, respectively, although 70% believed it was within their scope of practice to provide evidence-based advice. Dietitian respondents achieved a higher median score (maximum 10) in the following areas (practice = 6.5, knowledge = 8.0, confidence = 8.3) when compared with HP respondents (practice = 4.2, knowledge = 7.0, confidence = 5.4). The median attitude score for both groups was 6.0. Conclusions: HPs are receptive to providing evidence-based weight loss messages to overweight/obese clients in their current practice. However, weight management training is required to enhance HPs' knowledge and skills in order to increase confidence and improve practice skills. Dietitians can assist HPs to ensure that clear, consistent, evidence-based messages are delivered to overweight clients throughout the health-care system