A scoping review of approaches used to develop plant-based diet quality indices.

Plant-based dietary patterns are comprised of a range of foods, and increasingly, diet quality indices are used to assess them and their associations with health outcomes. As the design of these indices varies, a review of existing indices is necessary to identify common features, strengths, and considerations. This scoping review aimed to synthesize the literature on plant-based diet quality indices by examining their 1) basis for development, 2) scoring methodology, and 3) validation approaches. MEDLINE, CINAHL, and Global Health databases were systematically searched from 1980 to 2022. Observational studies were included if they assessed plant-based diets in adults, using an a priori methodology with food-based components. Studies conducted among pregnant/lactating people were excluded. Thirty-five unique plant-based diet quality indices were identified in 137 included articles published between 2007 and 2022. Indices were developed to reflect epidemiological evidence for associations between foods and health outcomes (n = 16 indices), previous diet quality indices (n = 16), country-specific dietary guidelines (n = 9), or foods from traditional dietary patterns (n = 6). Indices included 4 to 33 food groups, with fruits (n = 32), vegetables (n = 32), and grains (n = 30) the most common. Index scoring comprised of population-specific percentile cutoffs (n = 18) and normative cutoffs (n = 13). Twenty indices differentiated between healthy and less healthy plant-based foods when scoring intakes. Validation methods included construct validity (n = 26), reliability (n = 20), and criterion validity (n = 5). This review highlights that most plant-based diet quality indices were derived from epidemiological research, the majority of indices differentially scored healthy and unhealthy plant and animal foods, and indices were most often evaluated for construct validity and reliability. To ensure best practice use and reporting of plant-based dietary patterns, researchers should consider the basis for development, methodology, and validation when identifying appropriate plant-based diet quality indices for use in research contexts.

The association between dietary intake and cardiometabolic risk factors among obese adolescents in Indonesia.

BACKGROUND AND OBJECTIVE: Poor diets, characterized by excess fat, sugar and sodium intakes, are considered to be one of the most important modifiable risk factors for cardiovascular disease. Diet patterns and intakes during adolescence may persist into adulthood and impact on risk for chronic disease later in life. We aimed to evaluate the dietary intake of obese adolescents and its relationship to cardiometabolic health including lipid status and glycemic control. METHODS AND STUDY DESIGN: This was a cross-sectional study of obese children aged 15 to < 18 years in Yogyakarta, Indonesia. All children had a medical history performed including a physical examination and fasting blood sample. Dietary intake was assessed using a semi-quantitative recall food frequency questionnaire. Multivariable linear regression model was performed to determine the relationship between dietary intakes and cardiovascular disease risks and to adjust for potential confounders. RESULTS: Of 179 adolescents, 101 (57.4%) were male and median age was 16.4 (15.0-17.9) years. The majority of adolescents (98%) had inadequate intake of fibre and exceeded intakes of total fat (65%) and total sugar (36%). There was statistically significant correlation found in the multivariable linear regression analysis between fibre intake and HDL cholesterol after adjusting for potential confounders (ß = 0.165; p = 0.033). CONCLUSIONS: This study demonstrates that there is a high proportion of obese Indonesian adolescents with poor dietary intakes. There was relationship observed between intake of nutrients of concern (fibre) and cardiometabolic risk factor among this sample of obese adolescents. Future research should examine overall dietary patterns in more detail among this population to elucidate the role of poor diet intakes in development of cardiovascular disease risk factors in young people transitioning into adulthood.

Are meal kits health promoting? Nutritional analysis of meals from an Australian meal kit service.

SUMMARY: Meal kits are popular for consumers seeking greater convenience in preparing meals at home. The market share for meal kit subscription services (MKSSs) is growing in developed nations including Australia, however, literature about their health promoting qualities, e.g. nutritional composition, is scarce. This study aimed to assess the characteristics and nutritional composition of meals offered from an MKSS over 12 months. Nutritional data were extracted from recipes available to order from HelloFresh in Australia from 1 July 2017 to 30 June 2018. In total, 346 (251 unique) recipes were retrieved. Per serve (median size 580 g), meals contained a median of 2840 kJ (678 kcal) of energy, 58 g carbohydrate (14 g sugar), 44 g protein, 28 g total fat (8 g saturated fat) and 839 mg sodium. Median energy from macronutrients was total fat (38%), carbohydrates (34%), protein (25%) and saturated fat (11%). This paper is the first to describe characteristics of recipes available from an MKSS over a 12-month period of time. With their growing popularity, meal kit delivery services have the capacity to influence consumer food behaviours, diets and subsequently population health. MKSSs may function to promote health though education, training, and enabling home cooking behaviours, and may be a powerful commitment device for home cooking behaviour change. However, it is important for health professionals, including dietitians and nutritionists, to understand the nutritional risks, benefits and suitability of this contemporary mealtime option before recommending them to clients and members of the public as part of health promotion. LAY SUMMARY: Meal kit delivery services are growing in popularity in developed countries, complementing busy lifestyles with pre-measured ingredients and recipe instructions delivered to the home. These meal kits have the ability to influence consumer diets and population health, and may support health promoting diet behaviours, e.g. eating vegetables, and enable home cooking. In this study, we reviewed a years' worth of recipes from a popular meal kit service. We report that a typical recipe contained approximately nine different ingredients, comprising three vegetables and required three ingredients from the home pantry. Meals took ∼35 min to prepare and were found to be relatively high in energy from fat and protein, and relatively low in energy from carbohydrates. The level of sodium varied widely and some meals exceeded the Australian Suggested Dietary Target for sodium (<2000 mg). Meal kit recipes were found to have health promoting qualities, frequently including vegetable ingredients, however, improvements to recipes would make these meal kits more health promoting. Current diet intakes and the nutritional composition of meal kits recipes should be reviewed before being recommended by health professionals.

Cross-Sectional Analysis of Calories and Nutrients of Concern in Canadian Chain Restaurant Menu Items in 2016.

INTRODUCTION: The nutritional quality of restaurant foods in Canada is not monitored by government and limited research has evaluated the nutrient content of these foods. Given the increasing proportion of foods consumed outside the home, this study aims to assess levels of nutrients of public health concern in Canadian fast-food and sit-down restaurant menu items. METHODS: Levels of calories, saturated fat, sodium, and sugar of 10,285 menu items from 90 national chain restaurants in Canada were assessed. Data were collected in 2016, extracted and analyzed between 2018 and 2020, and presented overall and by category. Levels in fast-food and sit-down restaurant establishments were compared. RESULTS: Overall mean levels of saturated fat, sodium, and sugar were high. Entrées contained on average 52% of the total daily value for sodium (1,256 mg/serving) and 45% of the daily value for saturated fat (8.9 g/serving). Beverages and desserts had high levels of total sugar (mean=44 g and 32 g/serving, respectively) but tended to be low in sodium. Sit-down restaurant items had significantly (p≤0.0001) higher levels of calories, saturated fat, and sodium overall, although fast-food restaurant items had higher average sugar levels because of the higher number of beverage and dessert items. CONCLUSIONS: Levels of nutrients of concern in Canadian menu items are excessive among most food categories. As the frequency of eating out in restaurants rises, government policies to promote reformulation and increase transparency of the nutritional content of these items are required to reduce their negative impact on public health.

Orthorexia nervosa: examining the Eating Habits Questionnaire's reliability and validity, and its links to dietary adequacy among adult women.

OBJECTIVE: There has been increasing interest in identifying individuals with pathological healthy eating behaviours, or orthorexia nervosa (ON). This study aimed to investigate the validity (construct- and criterion-related) and reliability (internal consistency) of the Eating Habits Questionnaire (EHQ) as a measure of ON. A secondary aim was to examine how the EHQ would predict a distinct feature of ON, adequate dietary intake. DESIGN: Cross-sectional online questionnaire incorporating existing measures of ON and dietary intake. SETTING: Participants were recruited online via social media and a university's research webpage. PARTICIPANTS: Women (n 286) ranging in age from 17 to 73 years. RESULTS: Exploratory factor analysis established that the EHQ represented four ON dimensions (Healthy Eating Cognitions, Dietary Restriction, Diet Superiority and Social Impairment), inconsistent with the scale's original three dimensions (Problems, Knowledge and Feelings). Cronbach's α coefficients ranged from 0·72 to 0·80 for the four subscales and was 0·89 for the total EHQ scale. Criterion-related validity revealed a significant moderate to strong correlation (r = -0·54, P < 0·001) between the EHQ and ORTO-10 (a ten-item version of ORTO-15). The EHQ, particularly the EHQ-Diet superiority subscale, was found to be predictive of better, as opposed to, poorer dietary adequacy. CONCLUSIONS: Findings suggest that improvements still need to be made to the EHQ for it to be a valid and reliable measure of ON. Ideally, new assessment tools based on established diagnostic criteria are needed to advance our understanding of ON.

Are Clean Eating Blogs a Source of Healthy Recipes? A Comparative Study of the Nutrient Composition of Foods with and without Clean Eating Claims.

Food blogs are an increasingly popular source of information about food and nutrition. There is a perception that foods published on clean eating blogs, which promote unprocessed foods, are healthier than comparable foods without these claims. However, foods with these claims and their nutrient composition have not previously been evaluated. The purpose of the study was to describe the nutritional content of clean eating recipes compared to recipes without clean eating claims and the nutritional guidelines published by the World Health Organisation (WHO). Clean eating recipes were systematically selected from 13 popular clean eating blogs and were described and compared with control recipes without clean eating claims. The nutrient profiles from the included recipes were summarised and evaluated against criteria from WHO recommendations for chronic disease prevention and criteria from the U.K. Food Standards Agency. Data for 86 clean eating recipes were extracted that represented five food categories: breakfast, snacks, treats, desserts, and smoothies. These were matched with 86 control recipes without clean eating claims. The clean eating recipes, per portion, provide the equivalent of 15% of daily energy intake. The average serving sizes were not significantly different between clean eating and control recipes. Overall, the clean eating recipes contained significantly more protein (8.1 ± 7.3 g vs. 5.7 ± 4.1 g, p = 0.01), fat (15.8 ± 10.6 g vs. 12.4 ± 9.3 g, p = 0.03), and fibre (5.0 ± 4.3 g vs. 2.8 ± 2.9 g, p < 0.01) per serving than control recipes. There were no significant differences between clean eating and control recipes with respect to the energy (1280 ± 714 kJ vs. 1137 ± 600 kJ, p = 0.16), carbohydrate (31.5 ± 27.3 g vs. 33.9 ± 19.4 g, p = 0.51), sugar (21.1 ± 20.9 g vs. 23.2 ± 14.9 g, p = 0.46), and sodium content (196.7 ± 269 vs. 155.8 ± 160.8, p = 0.23). Less than 10% of clean eating and control recipes met the WHO constraints for proportions of energy from fat and sugar intake. A simulated nutrient profile of an average clean and control recipe shows that nutrients for both are similarly classified as moderate to high in fat, saturated fat, salt, and sugar. Foods with clean eating claims contained the same amount of energy, sugar, and sodium as foods without those claims. Clean eating claims are potentially misleading for consumers who may believe these foods are healthy alternatives, potentially undermining people's efforts to eat a healthy diet.

The Dirt on Clean Eating: A Cross Sectional Analysis of Dietary Intake, Restrained Eating and Opinions about Clean Eating among Women.

Clean eating is understood in broad terms to be an approach to eating which promotes the exclusion of processed foods. Social media and websites which promote clean eating are becoming increasingly popular as sources of nutrition information. Currently, there is a lack of knowledge regarding women's opinions about clean eating sites and their influence on eating behaviour. The aim of the present study was to investigate differences in dietary intake, dietary restraint and opinions about clean eating between women who had, and women who had never adhered to dietary advice from clean eating sites. Using a cross-sectional survey design, women (n = 762) ranging in age from 17⁻55 completed a self-report questionnaire on eating behaviour and beliefs about clean eating. Findings showed that 25.5% of the sample adhered to dietary advice from a clean eating site sometimes, often or very often. A significantly higher proportion of women who had adhered to dietary advice from clean eating sites met dietary guidelines for the consumption of fruit, meats and alternatives compared to women who had seldom or never adhered. Adherers also had significantly higher levels of restrained eating and were more positive about clean eating in general in comparison to those who seldom or never adhered. Results provide new information about exposure to clean eating sites and how they may influence women's eating practices. These preliminary findings suggest additional studies are required to better understand the influence of clean eating sites, particularly with regard to whether the information on such sites are from reputable sources and to what degree their recommendations may be problematic for individuals with eating concerns.

Comparison of nutrient profiling models for assessing the nutritional quality of foods: a validation study.

Nutrient profiling (NP) is a method for evaluating the healthfulness of foods. Although many NP models exist, most have not been validated. This study aimed to examine the content and construct/convergent validity of five models from different regions: Australia/New Zealand (FSANZ), France (Nutri-Score), Canada (HCST), Europe (EURO) and Americas (PAHO). Using data from the 2013 UofT Food Label Information Program (n15342 foods/beverages), construct/convergent validity was assessed by comparing the classifications of foods determined by each model to a previously validated model, which served as the reference (Ofcom). The parameters assessed included associations (Cochran-Armitage trend test), agreement (κ statistic) and discordant classifications (McNemar's test). Analyses were conducted across all foods and by food category. On the basis of the nutrients/components considered by each model, all models exhibited moderate content validity. Although positive associations were observed between each model and Ofcom (all P trend<0·001), agreement with Ofcom was 'near perfect' for FSANZ (κ=0·89) and Nutri-Score (κ=0·83), 'moderate' for EURO (κ=0·54) and 'fair' for PAHO (κ=0·28) and HCST (κ=0·26). There were discordant classifications with Ofcom for 5·3 % (FSANZ), 8·3 % (Nutri-Score), 22·0 % (EURO), 33·4 % (PAHO) and 37·0 % (HCST) of foods (all P<0·001). Construct/convergent validity was confirmed between FSANZ and Nutri-Score v. Ofcom, and to a lesser extent between EURO v. Ofcom. Numerous incongruencies with Ofcom were identified for HCST and PAHO, which highlights the importance of examining classifications across food categories, the level at which differences between models become apparent. These results may be informative for regulators seeking to adapt and validate existing models for use in country-specific applications.

Eating occasions and the contribution of foods to sodium and potassium intakes in adults.

OBJECTIVE: To examine dietary Na and K intake at eating occasions in Australian adults and identify the contribution of major food sources to Na and K at different eating occasions. DESIGN: Secondary analysis of 24 h recall diet data from the Australian Health Survey (2011-2013). SETTING: Nationally representative survey in Australia. SUBJECTS: Male and female Australians aged 18-84 years (n 7818). RESULTS: Dinner contributed the greatest proportion to total daily Na intake (33 %) and K intake (35 %). Na density was highest at lunch (380 mg/MJ) and K density highest at between-meal time eating occasions (401 mg/MJ). Between-meal time eating occasions provided 20 % of daily Na intake and 26 % of daily K intake. The major food group sources of Na were different at meal times (breads and mixed dishes) compared with between-meal times (cakes, muffins, scones, cake-type desserts). The top food group sources of K at meal times were potatoes and unprocessed meat products and dishes. CONCLUSIONS: Foods which contributed to Na and K intake differed according to eating occasion. Major food sources of Na were bread and processed foods. Major food sources of K were potatoes and meat products and dishes. Public health messages that emphasise meal-based advice and diet patterns high in vegetables, fruits and unprocessed foods may also aid reduction in dietary Na intake and increase in dietary K intake.

Dietary intake of working women with children does not appear to be influenced by hours of employment: A secondary analysis of the Australian Health Survey (2011-2013).

UNLABELLED: Women with children often fulfil multiple roles of running a household, raising a family and working outside the home. Good nutrition during this time is important to optimise their performance and prevent lifestyle diseases. Women also act as nutritional gatekeepers for their family. The dual burden of paid employment and unpaid family work may be associated with time scarcity in mothers which can impact food preparation and therefore nutritional adequacy. The aim of this study was to examine the diet of women who lived with children by comparison of hours worked. METHODS: This was a secondary analysis of the Australian National Nutrition and Physical Activity Survey 2011-12. Subjects were women aged 18-65 years who resided with ≥1 child (<18 years). Women were grouped according to hours of employment: not working; working <25 h a week; and working ≥25 hours a week. Data from two 24-h dietary recalls were used to compare differences between groups in nutrient intake and proportion of energy from discretionary foods. Covariates included were age, education, smoker status, Socio-Economic Indexes for Areas (SEIFA), number of persons in household, week or weekend day of the survey and the sequence of recalls. RESULTS: Analyses included 1869 women. Dietary intakes varied minimally between groups with intakes of fibre, vitamin C, and calcium lowest in the group not working. Overall diet quality was poor with >30% of energy coming from discretionary foods in all groups. CONCLUSIONS: Usual hours of employment per week have a minimal effect on diet quality in women with children. It is likely that different factors specific to each group contribute to the poor dietary intakes and should be further investigated.

Alcoholic beverage intake throughout the week and contribution to dietary energy intake in Australian adults.

OBJECTIVE: To assess alcoholic beverage intake among Australian adults and its contribution to dietary energy intake. DESIGN: Secondary analysis of a national dietary survey using 24 h dietary recall. SETTING: Australian National Nutrition and Physical Activity Survey (NNPAS) conducted from May 2011 to June 2012. SUBJECTS: Adults (n 9341) aged 19 years and over. RESULTS: On the day preceding the survey, 32·8% of Australian adults consumed one or more alcoholic drinks. The median contribution to total energy intake for consumers did not differ significantly between males and females (13·7% and 12·9%, respectively; P=0·10). The prevalence of consumption of alcoholic drinks on Friday, Saturday and Sunday was 38·8 (95% CI 37·1, 40·5)%, higher than the other days (28·6 (95% CI 27·5, 29·8)%). Consumers had a median daily intake of 4·0 standard drinks on the weekend compared with 3·0 standard drinks during the week (P<0·001). Beer was the most commonly consumed alcoholic beverage for men and white wine for women. The highest prevalence of alcoholic beverage intake occurred in the highest quintile of adjusted household income (42·7 (95% CI 40·4, 45·0)%) and the 'overweight' BMI category (40·3 (95% CI 38·5, 42·0)%). Alcoholic beverage intake among consumers was significantly different by household income quintile (median 3·84 (highest) v. 3·05 standard drinks (lowest); P<0·05) and by waist circumference category (median 4·09 standard drinks (highest)). CONCLUSIONS: Alcoholic drinks contribute substantially to the dietary energy intake of Australian adults. The type and pattern of consumption of alcoholic beverage intake should be considered in the development of strategies to improve dietary intake.

Validation of a Brief Dietary Assessment Tool for Estimating Dietary EPA and DHA Intake in Australian Adults at Risk of Cardiovascular Disease.

BACKGROUND: Short food frequency questionnaires (FFQs) are powerful screening instruments for estimating nutrient intakes and play an important role in risk stratification in vulnerable populations. Omega-3 fatty acids are of increasing importance in the prevention of chronic and degenerative disease, especially in older adults who are at higher risk of these chronic conditions. A short FFQ exists to rapidly assess omega-3 intake from marine sources, however it has not previously been validated for agreement with total omega-3 intake and ability to identify suboptimal omega-3 intakes in older adults or for use in Australia. OBJECTIVE: The aim of the study was to validate a 9-item marine omega-3 FFQ (MFQ) for assessment of omega-3 intake against a validated 74-item semiquantitative FFQ. METHODS: One hundred and eight participants (mean age 67 ± 10 years, 47% male) completed the MFQ designed to estimate omega-3 intake from marine sources and the 74-item FFQ designed to estimate usual omega-3 and total energy intake in addition to other nutrients. To test agreement between the two questionnaires for estimating total omega-3 intake, mean bias and 95% limits of agreement (LOA) were calculated. Sensitivity and specificity were assessed using 2 × 2 contingency tables based on whether participants did or did not meet National Heart Foundation (NHF) recommendations for omega-3 intake per day. RESULTS: Mean intake of omega-3 estimated from the MFQ was 210 ± 235 mg/day compared with 295 ± 260 mg/day as estimated by the FFQ. Mean bias (95% LOA) for omega-3 assessed by the two questionnaires was 89 mg/day (-475 mg to 653 mg). The MFQ achieved 98% sensitivity and 31% specificity for the omega-3 cut-off of 500 mg/day. When nutrient composition of the marine products were replaced with Australian data, mean intake of omega-3 was 230 ± 253 mg and the mean bias improved to 64 mg (-681 mg to 553 mg) and achieved 93% sensitivity and 40% specificity. CONCLUSIONS: The MFQ shows promise as a rapid screening tool for identifying older adults with intakes of omega-3 fatty acids likely to be below recommendations for chronic and degenerative disease risk reduction. Given the clinically meaningful mean bias and wide LOA, it cannot be recommended as an appropriate tool for the purpose of reporting average intake of individuals. Use of Australian nutrient data improved the mean bias of the tool in estimating total omega-3 intake. The values should be replaced and the MFQ could then be a useful tool for research purposes at the population level.

Change in dietary intake of adults with intermittent claudication undergoing a supervised exercise program and compared to matched controls.

BACKGROUND: Presence of numerous diet responsive comorbidities and high atherosclerotic burden among adults with intermittent claudication demands attention is given to diet in an effort to delay progression of peripheral artery disease. The aim of this study was to compare diet of adults with intermittent claudication: (a) against dietary recommendations; (b) following 12 weeks of supervised exercise training; and (c) against non-peripheral artery disease controls. METHODS: Diet was assessed using a food frequency questionnaire pre and post supervised exercise training. Pre-exercise diet was compared against Suggested Dietary Targets and against non-peripheral artery disease controls matched for gender, age and body weight. Pre-exercise diet was also compared against post-exercise diet. RESULTS: Pre-exercise 25/31 participants, 5/31 participants, 16/31 participants and 4/31 participants achieved recommendations for protein, carbohydrate, total fat and saturated fat respectively. Few achieved recommended intakes for fibre (3/31 participants), cholesterol (8/31 participants), folate (11/31 participants), potassium (1/31 participants), sodium (4/31 participants), retinol equivalents (1/31 participants) and vitamin C (3/31 participants). There were no differences observed between participants compared to controls in achievement of recommendations. Post-exercise, marginally more participants were able to achieve targets for cholesterol, sodium and vitamin C but not for any other nutrients. CONCLUSIONS: Despite evidence to support benefits of dietary modification in risk reduction of peripheral artery disease, adults with intermittent claudication continue to consume poor diets. Research is required to determine whether dietary changes can be achieved with greater attention to nutrition counselling and the impact assessed in terms of delayed disease progression and long term health outcomes. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01871779.

A reduction of 3 g/day from a usual 9 g/day salt diet improves endothelial function and decreases endothelin-1 in a randomised cross_over study in normotensive overweight and obese subjects.

BACKGROUND AND AIM: It is unclear if a modest reduction in dietary salt intake has beneficial effects on vascular function. The aim was to compare the effects of 9 g salt/day with 6 g salt/day intake on measures of vascular function and explore mechanisms of effect in overweight and obese adults. METHODS: Twenty-five overweight/obese subjects (BMI 27-40 kg/m(2)) completed a randomised cross-over study of 6 weeks each on a reduced salt (RS) (6 g/day) and usual salt diet (US) (9 g/day). Flow-mediated-dilatation (FMD), 24 h blood pressure (BP), augmentation index (AIx), pulse wave velocity (PWV), plasma and urinary nitrate/nitrite, asymmetric dimethylarginine (ADMA), renin, aldosterone and endothelin-1 and vascular adhesion molecules were measured after 2 days and 6 weeks. Adherence to the diets was determined from two 24 h urine collections. RESULTS: Urinary sodium excretion was 155 ± 58 mmol/24 h US vs 113 ± 45 mmol/24 h RS (p = 0.002). Following the RS diet there was a significant improvement in FMD from 3.5 ± 2.8% to 5.6 ± 2.8% (P < 0.001) and decrease in serum endothelin-1 from 1.45 ± 0.38 pg/ml to 1.25 ± 0.39 pg/ml (P < 0.05). Endothelium-independent vasodilatation was also significantly different between treatments (P < 0.05). AIx, PWV, serum ADMA and plasma and urinary nitrate/nitrite concentrations were not different between treatments. Change in FMD was related to the urinary sodium: creatinine ratio (r = -0.47, P < 0.05) and was independent of blood pressure. Aldosterone and renin were unchanged. CONCLUSIONS: A small reduction in dietary salt intake of 3 g/day improves endothelial function in normotensive overweight and obese subjects. This response may be mediated by serum endothelin-1. This small reduction in salt had no effect on aldosterone and renin concentrations. This trial was registered with the Australian and New Zealand Clinical Trials Registry Unique Identifier: ACTRN12609000321246 http://www.anzctr.org.au/ACTRN12609000321246.aspx.

Postprandial effects of a high salt meal on serum sodium, arterial stiffness, markers of nitric oxide production and markers of endothelial function.

AIM: The aim of the study was to determine if a high salt meal containing 65 mmol Na causes a rise in sodium concentrations and a reduction in plasma nitrate/nitrite concentrations (an index of nitric oxide production). Secondary aims were to determine the effects of a high salt meal on augmentation index (AIx) a measure of arterial stiffness and markers of endothelial function. METHODS AND RESULTS: In a randomised cross-over study 16 healthy normotensive adults consumed a low sodium soup containing 5 mmol Na and a high sodium soup containing 65 mmol Na. Sodium, plasma nitrate/nitrite, endothelin-1 (ET-1), C-reactive protein (CRP), vasopressin (AVP) and atrial natriuretic peptide (ANP) concentrations before and every 30 min after the soup for 2 h. Blood pressure (BP) and AI were also measured at these time points. There were significant increases in serum sodium, osmolality and chloride in response to the high sodium meal. However plasma nitrate/nitrite concentrations were not different between meals (meal p = 0.812; time p = 0.45; meal × time interaction p = 0.50). Plasma ANP, AVP and ET-1 were not different between meals. AI was significantly increased following the high sodium meal (p = 0.02) but there was no effect on BP. CONCLUSIONS: A meal containing 65 mmol Na increases serum sodium and arterial stiffness but does not alter postprandial nitrate/nitrite concentration in healthy normotensive individuals. Further research is needed to explore the mechanism by which salt affects vascular function in the postprandial period. This trial was registered with the Australian and New Zealand Clinical Trials Registry Unique Identifier: ACTRN12611000583943http://www.anzctr.org.au/trial_view.aspx?ID=343019.

Endothelial function is impaired after a high-salt meal in healthy subjects.

BACKGROUND: Dietary salt is related to blood pressure (BP), and cardiovascular disease and increased sodium intakes have been shown to impair vascular function. The effect of salt on endothelial function postprandially is unknown. OBJECTIVE: The aim was to investigate the postprandial effect of dietary salt on endothelial function as measured by flow-mediated dilatation (FMD) and peripheral arterial tonometry in healthy subjects. DESIGN: Sixteen healthy, normotensive subjects received a meal with added salt (HSM; 65 mmol Na) and a control low-salt meal (LSM; 5 mmol Na) on 2 separate occasions in a randomized order. Endothelial function was measured while fasting and postprandially at 30, 60, 90, and 120 min by using FMD and reactive hyperemia peripheral arterial tonometry. BP was also measured. RESULTS: Baseline FMD, reactive hyperemia index (RHI), and BP values were similar across interventions. Overall FMD was reduced 2 h postprandially. FMD was significantly more impaired after the HSM than after the LSM at 30 min [HSM (mean ± SD): 3.39 ± 2.44%; LSM: 6.05 ± 3.21%; P < 0.01] and at 60 min (HSM: 2.20 ± 2.77%; LSM: 4.64 ± 2.48%; P < 0.01). No significant differences in BP or RHI were observed between meals. CONCLUSIONS: An HSM, which reflects the typical amount of salt consumed in a commonly eaten meal, can significantly suppress brachial artery FMD within 30 min. These results suggest that high salt intakes have acute adverse effects on vascular dilatation in the postprandial state. This trial was registered at www.anzctr.org.au/trial_view.aspx?ID=335115 as ACTRN12610000124033.

Effects of a low-salt diet on flow-mediated dilatation in humans.

BACKGROUND: The effect of salt reduction on vascular function, assessed by brachial artery flow-mediated dilatation (FMD), is unknown. OBJECTIVE: Our aim was to compare the effects of a low-salt (LS; 50 mmol Na/d) diet with those of a usual-salt (US; 150 mmol Na/d) diet on FMD. DESIGN: This was a randomized crossover design in which 29 overweight and obese normotensive men and women followed an LS diet and a US diet for 2 wk. Both diets had similar potassium and saturated fat contents and were designed to ensure weight stability. After each intervention, FMD, pulse wave velocity, augmentation index, and blood pressure were measured. RESULTS: FMD was significantly greater (P = 0.001) with the LS diet (4.89 +/- 2.42%) than with the US diet (3.37 +/- 2.10%), systolic blood pressure was significantly (P = 0.02) lower with the LS diet (112 +/- 11 mm Hg) than with the US diet (117 +/- 13 mm Hg), and 24-h sodium excretion was significantly lower (P = 0.0001) with the LS diet (64.1 +/- 41.3 mmol) than with the US diet (156.3 +/- 56.7 mmol). There was no correlation between change in FMD and change in 24-h sodium excretion or change in blood pressure. No significant changes in augmentation index or pulse wave velocity were observed. CONCLUSIONS: Salt reduction improves endothelium-dependant vasodilation in normotensive subjects independently of the changes in measured resting clinic blood pressure. These findings suggest additional cardioprotective effects of salt reduction beyond blood pressure reduction. The trial is registered with the Australian and New Zealand Clinical Trials Registry (unique identifier: ANZCTR12607000381482; http://www.anzctr.org.au/trial_view.aspx?ID=82159).