Using Genetics to Inform Interventions Related to Sodium and Potassium in Hypertension.

BACKGROUND: Hypertension is a key risk factor for major adverse cardiovascular events but remains difficult to treat in many individuals. Dietary interventions are an effective approach to lower blood pressure (BP) but are not equally effective across all individuals. BP is heritable, and genetics may be a useful tool to overcome treatment response heterogeneity. We investigated whether the genetics of BP could be used to identify individuals with hypertension who may receive a particular benefit from lowering sodium intake and boosting potassium levels. METHODS: In this observational genetic study, we leveraged cross-sectional data from up to 296 475 genotyped individuals drawn from the UK Biobank cohort for whom BP and urinary electrolytes (sodium and potassium), biomarkers of sodium and potassium intake, were measured. Biologically directed genetic scores for BP were constructed specifically among pathways related to sodium and potassium biology (pharmagenic enrichment scores), as well as unannotated genome-wide scores (conventional polygenic scores). We then tested whether there was a gene-by-environment interaction between urinary electrolytes and these genetic scores on BP. RESULTS: Genetic risk and urinary electrolytes both independently correlated with BP. However, urinary sodium was associated with a larger BP increase among individuals with higher genetic risk in sodium- and potassium-related pathways than in those with comparatively lower genetic risk. For example, each SD in urinary sodium was associated with a 1.47-mm Hg increase in systolic BP for those in the top 10% of the distribution of genetic risk in sodium and potassium transport pathways versus a 0.97-mm Hg systolic BP increase in the lowest 10% (P=1.95×10-3). This interaction with urinary sodium remained when considering estimated glomerular filtration rate and indexing sodium to urinary creatinine. There was no strong evidence of an interaction between urinary sodium and a standard genome-wide polygenic score of BP. CONCLUSIONS: The data suggest that genetic risk in sodium and potassium pathways could be used in a precision medicine model to direct interventions more specifically in the management of hypertension. Intervention studies are warranted.

Happy Little Vegemites™! An analysis of the contribution of yeast extract spreads and tomato-based sauces to nutrient intake adequacy in Australia.

BACKGROUND: Yeast extract spreads and tomato-based sauces (i.e., ketchup) are consumed regularly by the Australian population. Therefore, there is a need to explore the contribution of these condiments to nutrient intakes among Australians. METHODS: The present study comprises a secondary analysis of data from the 2011-2012 Australian National Nutrition and Physical Activity Survey. Dietary intake data were undertaken for 12,153 Australians aged ≥ 2 years, using 24-h recalls. Yeast extract spreads and tomato-based sauces were categorised based on how they were defined in the Australian Food and Nutrient (AUSNUT) 2011-2013 database. Kruskal-Wallis H tests and the post-hoc Dunn's test with Bonferroni correction were applied to test whether a significant difference existed in the percentage contribution of yeast extract spreads and tomato-based sauces to intakes of select nutrients. RESULTS: In total, 19.6% (n = 2384) of the population sample consumed yeast extract spreads and/or tomato-based sauces during the 24-h recall. The percentage contribution of yeast extract spreads to daily intakes of sodium, potassium, thiamine, riboflavin, niacin, folate, magnesium, iron, zinc and iodine were significantly higher in line with a greater quantity of yeast extract spread consumed (p < 0.05). The percentage contribution of tomato-based sauces to daily intakes of sodium, potassium, riboflavin, niacin, folate, beta-carotene, magnesium, iron, zinc and iodine was increased significantly with a greater quantity of tomato-based sauces consumed (p < 0.05). CONCLUSIONS: Consumption of yeast extracts and tomato-based sauces contribute to greater intake of key nutrients, such as B-vitamins and beta-carotene, and may assist in meeting key nutrient reference values. However, consumption of these sauces and condiments also resulted in greater intakes of sodium, contributing to population intakes exceeding recommendations. Reducing sodium content of frequently consumed condiments may potentially assist in lowering population intakes, at the same time as preserving intakes of other important nutrients.

'Nutrition has everything to do with wound healing'-health professionals' perceptions of assessment and management of nutrition in individuals with diabetes-related foot ulceration.

Determine how healthcare professionals perceive their role in nutrition assessment and management, and explore barriers and enablers to assessment and management of nutrition in individuals with DFU. Mixed methods including a cross-sectional online survey derived from current international guidelines and theoretical domains framework, and semi-structured interviews with conventional content analysis was performed. One hundred and ninety-one participants completed the survey, with 19 participating in interviews. Many health professionals are not confident in their ability in this area of practice, are uncertain their nutrition advice or management will be effective in assisting wound healing outcomes and are uncertain their intervention would result in adequate behaviour change by the individual with DFU. Major barriers to implementation of nutrition assessment and management were: inadequate time, lack of knowledge and lack of clinical guidance and enablers were as follows: professional development, a standardised clinical pathway and screening tool and a resource addressing wound healing and diabetes management. Nutrition assessment and management in individuals with DFU is not consistently applied. Whilst health professionals believed nutrition was important for wound healing, they lacked confidence in implementing into their practice. Further dissemination of existing guidance and implementation of education programs and resources would help overcome cited barriers.

Delivery of telehealth nutrition and physical activity interventions to adults living in rural areas: a scoping review.

BACKGROUND: Lifestyle behaviours related to smoking, alcohol, nutrition, and physical activity are leading risk factors for the development of chronic disease. For people in rural areas, access to individualised lifestyle services targeting behaviour change may be improved by using telehealth. However, the scope of literature investigating telehealth lifestyle behaviour change interventions for rural populations is unknown, making it difficult to ascertain whether telehealth interventions require adaptation for rural context via a systematic review. This scoping review aimed to address this gap, by mapping existing literature describing telehealth lifestyle interventions delivered to rural populations to determine if there is scope for systematic review of intervention effectiveness in this research topic. METHODS: The PRISMA extension for scoping review checklist guided the processes of this scoping review. A search of eight electronic databases reported in English language until June 2023 was conducted. Eligible studies included adults (18 years and over), who lived in rural areas of high-income countries and undertook at least one synchronous (video or phone consultation) telehealth intervention that addressed either addictive (smoking or alcohol), or non-addictive lifestyle behaviours (nutrition or physical activity). Studies targeting addictive and non-addictive behaviours were separated after full text screening to account for the involvement of addictive substances in smoking and alcohol studies that may impact behaviour change interventions described. Studies targeting nutrition and/or physical activity interventions are presented here. RESULTS: The search strategy identified 17179 citations across eight databases, with 7440 unique citations once duplicates were removed. Full texts for 492 citations were retrieved and screened for inclusion with 85 publications reporting on 73 studies eligible for data extraction and analysis. Of this, addictive behaviours were comprised of 15 publications from 13 studies. Non-addictive behaviours included 70 publications from 58 studies and are reported here. Most interventions were delivered within the United States of America (n = 43, 74.1%). The most common study design reported was Randomised Control Trial (n = 27, 46.6%). Included studies involved synchronous telehealth interventions targeting nutrition (11, 18.9%), physical activity (5, 8.6%) or nutrition and physical activity (41, 70.7%) and were delivered predominately via videoconference (n = 17, 29.3%). CONCLUSIONS: Despite differences in intervention characteristics, the number of randomised control trials published suggests sufficient scope for future systematic reviews to determine intervention effectiveness related to nutrition and physical activity telehealth interventions for rural populations. TRIAL REGISTRATION: The scoping review protocol was not pre-registered.

Impact and evaluation of an online culinary nutrition course for health, education and industry professionals to promote vegetable knowledge and consumption.

BACKGROUND: Poor diet, including inadequate vegetable intake, is a leading risk factor for noncommunicable disease. Culinary and nutrition education provided to trainee and practising health and education professionals is an emerging strategy to promote improved dietary intake, including vegetable consumption. We evaluated the impact and feasibility of an online culinary medicine and nutrition (CM/CN) short course for health, education and vegetable industry professionals. The course aimed to improve participants' skills and confidence to prepare vegetables, knowledge of evidence-based nutrition information and recommendations for improving vegetable consumption and diet quality. METHODS: A pre-post study consisting of two separate groups participating in two course rounds recruited practising professionals (n = 30) working in health; community, adult and/or culinary education; and the vegetable industry. Evaluation assessed diet quality, vegetable consumption barriers, cooking and food skill confidence, nutrition knowledge and process measures. RESULTS: Seventeen participants (68%) completed the programme. Pre- to postintervention statistically significant increases in vegetables (M 1.3, SD 2.2), fruit (M 1.6, SD 3.1), and breads and cereal (M 1.1, SD 1.7) intakes were observed. Statistically significant increases and large effect sizes for mean food skill confidence scores (M 8.9, SD 15.4, Cohen's d 0.56) and nutrition knowledge scores (M 6.2, SD 15.4, Cohen's d 0.83) were also observed pre- to postintervention. CONCLUSIONS: The short online course was feasible and improved diet quality, food skill confidence and nutrition knowledge. Online CM/CN education for practising professionals represents a promising area of research. Future research involving a larger study sample and a more rigorous study design such as a randomised control trial is warranted.

Facilitators and barriers to providing culinary nutrition, culinary medicine and behaviour change support: An online cross-sectional survey of Australian health and education professionals.

BACKGROUND: An Australia wide cross-sectional online survey examined facilitators and barriers of health and education professionals to providing culinary nutrition (CN) and culinary medicine (CM) education and behaviour change support in usual practice, in addition to identifying continuing professional development (CPD) needs in this domain. METHODS: Survey items included socio-demographic characteristics, cooking and food skills confidence, nutrition knowledge (PKB-7), fruit and vegetable intake (FAVVA) and CPD needs. Data were summarised descriptively. RESULTS: Of 277 participants, 65% were likely/somewhat likely to participate in CN CPD. Mean (SD) cooking and food skill confidence scores were 73 (17.5) and 107.2 (24), out of 98 and 147, respectively. Mean PKB-7 score was 3.7 (1.4), out of 7. Mean FAVVA score was 98 (29), out of 190. CONCLUSIONS: Gaps in knowledge and limited time were the greatest modifiable barriers to providing CM/CN education and behaviour change support in practice. Health and education professionals are interested in CPD conducted by dietitians and culinary professionals to enhance their knowledge of CM/CN and behaviour change support.

Do sauces, condiments and seasonings contribute important amounts of nutrients to Australian dietary intakes?

BACKGROUND: Dietary assessment commonly focuses on particular foods/food groups as indicators of overall dietary intake. Accompaniments such as sauces are not often a focus. The present study describes daily intakes of sauces, condiments and seasonings (SCS) using the most recent Australian National Nutrition and Physical Activity Survey (NNPAS), as well as the contribution to total energy and selected nutrient intakes. METHODS: NNPAS dietary data were collected by one 24-h recall for 12,153 individuals aged ≥ 2 years (53% female, 29% aged 31-50 years). SCS (i.e., any food items not normally consumed as a food itself, consumed as an addition to a dish after cooking/preparation to enhance flavour) were identified/coded within the dietary data and reported in terms of how they were consumed, primary composition, and contribution to total daily energy and selected macro- and micronutrient intakes. RESULTS: Most participants (85.1%) reported consuming at least one SCS on the day of the recall (median [interquartile range], 2 [1-4]). SCS were predominantly consumed within main meals (breakfast, lunch, dinner) (73.9%), and were predominantly sugar/sugar products (e.g., white sugar) (35.0%), or fats and oils (e.g., butter) (25.9%). SCS contributed a median (interquartile range) of 3.8% (1.1-7.9) of total energy, 5.3% (0.0-15.5) of fat, 2.3% (0.1-6.6) of carbohydrate and 0.2% (0.01-1.2) of protein intake. SCS made the largest contribution towards vitamin E (females median 3.6%; males median 3.4%) and sodium intakes (females median 3.0%; males median 2.9%). CONCLUSIONS: Although SCS contribute a small proportion of total energy and nutrient intakes in the Australian population, the contribution is more substantial for some nutrients and population groups.

Most individuals with diabetes-related foot ulceration do not meet dietary consensus guidelines for wound healing.

The inaugural expert consensus and guidance for Nutrition Interventions in Adults with Diabetic Foot Ulcers (DFU) have been welcomed by clinicians internationally. This short report aimed to determine how the macronutrient and micronutrient status of individuals living with DFU compared to the American Limb Preservation Society Nutrition Interventions in Adults with DFU expert consensus and guidance. Descriptive analysis was conducted as a secondary analysis of an existing dataset. Mean (SD) dietary intake, the proportion meeting the nutrition recommendations and the proportion exceeding the upper limit (UL) for specific vitamins and minerals were reported. Most individuals with DFU do not meet current consensus guidelines for optimal dietary intake for wound healing, with inadequacies evident for fibre, zinc, protein, vitamin E and vitamin A. Future iterations of the consensus guideline should consider using evidence-informed recommendations for clinical practice, with the inclusion of all nutrients that are essential for wound healing in DFU.

The relationship between urinary polyphenol metabolites and dietary polyphenol intakes in young adults.

Spot urinary polyphenols have potential as a biomarker of polyphenol-rich food intakes. The aim of this study is to explore the relationship between spot urinary polyphenols and polyphenol intakes from polyphenol-rich food sources. Young adults (18-24 years old) were recruited into a sub-study of an online intervention aimed at improving diet quality. Participants' intake of polyphenols and polyphenol-rich foods was assessed at baseline and 3 months using repeated 24-h recalls. A spot urine sample was collected at each session, with samples analysed for polyphenol metabolites using LC-MS. To assess the strength of the relationship between urinary polyphenols and dietary polyphenols, Spearman correlations were used. Linear mixed models further evaluated the relationship between polyphenol intakes and urinary excretion. Total urinary polyphenols and hippuric acid (HA) demonstrated moderate correlation with total polyphenol intakes (rs = 0·29-0·47). HA and caffeic acid were moderately correlated with polyphenols from tea/coffee (rs = 0·26-0·46). Using linear mixed models, increases in intakes of total polyphenols or polyphenols from tea/coffee or oil resulted in a greater excretion of HA, whereas a negative relationship was observed between soya polyphenols and HA, suggesting that participants with higher intakes of soya polyphenols had a lower excretion of HA. Findings suggest that total urinary polyphenols may be a promising biomarker of total polyphenol intakes foods and drinks and that HA may be a biomarker of total polyphenol intakes and polyphenols from tea/coffee. Caffeic acid warrants further investigation as a potential biomarker of polyphenols from tea/coffee.

Ultra-processed food intakes associated with 'food addiction' in young adults.

Exploring potentially addictive foods and food components is a recent research focus. Few studies have evaluated this based on level of food processing using the NOVA classification system. This study compared intakes of ultra-processed foods in young adults with and without food addiction. Secondary analysis of online cross-sectional survey data was conducted. The sample included 735 young Australian adults (18-35 years). Dietary intake was assessed by food frequency questionnaire and coded using NOVA to determine percentage energy (%E) from each of the four NOVA categories (unprocessed; processed culinary ingredients; processed; ultra-processed). Food addiction was assessed using the Yale Food Addiction Scale (YFAS). Linear regression models, adjusted for age, gender and body mass index (BMI), were developed to examine the association between %E from NOVA categories with food addiction status and number of symptoms. Sample mean age was 24.7 ± 4.2 years, 85% were female, 67% within healthy weight BMI range, and 20% classified as food addicted. Participants consumed 34.3 ± 13.4 %E from ultra-processed foods. Young adults classified as food addicted consumed a higher %E from ultra-processed foods (ß = 3.954, p = 0.002) and a lower %E from unprocessed foods (ß = -2.743, p = 0.010) than those classified as not food addicted. For each additional food addiction symptom reported, the %E from ultra-processed foods was higher (ß = 1.693, p < 0.001) and %E from unprocessed foods was lower (ß = -1.238, p < 0.001). Results demonstrate an association between YFAS assessed food addiction and higher intakes of ultra-processed foods, providing an important new perspective on the relationship between self-reported diet and food addiction in young adults. Future research should evaluate the relationship between food addiction, ultra-processed food intakes and health in longitudinal studies in order to inform potential treatment approaches.

Variation in cardiovascular disease risk factors among older adults in the Hunter Community Study cohort: A comparison of diet quality versus polygenic risk score.

BACKGROUND: The interplay between cardiovascular disease (CVD) genetic risk indexed by a polygenic risk score (PRS) and diet quality still requires further investigation amongst older adults or those with established or treated CVD. The present study aimed to evaluate the relative contribution of diet quality, measured using the Australian Recommended Food Score (ARFS) and PRS, with respect to explaining variation in plasma lipids CVD outcomes in the Hunter Cohort. METHODS: The study comprised a secondary analysis of cross-sectional data from the Hunter Cohort study. Single-nucleotide polymorphisms from previously derived polygenic scores (PGSs) for three lipid classes were obtained: low-density lipoprotein, high-density lipoprotein and triglycerides, as well as PRS for coronary artery disease (CAD) from the PGS catalogue. Regression modelling and odds ratios were used to determine associations between PRS, ARFS and CVD risk. RESULTS: In total, 1703 participants were included: mean ± SD age 66 ± 7.4 years, 51% female, mean ± SD total ARFS 28.1 ± 8 (out of 74). Total diet quality and vegetable subscale were not significantly associated with measured lipids. By contrast, PGS for each lipid demonstrated a markedly strong, statistically significant correlation with its respective measured lipid. There was a significant association between CAD PRS and 5/6 CVD phenotypes (all except atrial fibrillation), with the largest effect size shown with coronary bypass. Adding dietary intake as a covariate did not change this relationship. CONCLUSIONS: Lipid PGS explained more variance in measured lipids than diet quality. However, the poor diet quality observed in the current cohort may have limited the ability to observe any beneficial effects. Future research should investigate whether the diet quality of older adults can be improved and also the effect of these improvements on changes in polygenic risk.

Workplace Health Promotion Programs Targeting Smoking, Nutrition, Physical Activity, and Obesity in Men: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

The workplace has been highlighted as a potential setting to deliver health promotion programs to target modifiable health behaviors that contribute to chronic disease. This review evaluated the effectiveness of interventions implemented within the workplace that targeted either smoking, nutrition, alcohol, physical activity, and/or overweight and obesity in men. A review protocol was prospectively registered through PROSPERO (CRD42021293398). Five electronic bibliographic databases were searched for randomized controlled trials conducted in the workplace assessing chronic disease risk factors in men from January 2010 to August 2021. Eleven studies were included, reporting on overweight and obesity n = 8, physical activity n = 7, nutrition n = 4, alcohol n = 3, smoking n = 3, with eight studies assessing multiple outcomes. Results were mixed. Narrative synthesis highlighted studies reporting improvements to snacking frequency, sugar sweetened beverage consumption, and physical activity (METs and Vo2 max). Meta-analysis highlighted pooled mean decrease in body weight of -0.28 kg up to 3 months; -1.38 kg for >3 months, and pooled mean decrease in body mass index 0.06 kg/m2 up to 3 months; -0.27 kg/m2 for >3 months. Despite the encouraging direction of the relationship, results were not statistically significant (p > .05). Findings underscore the potential of workplace health promotion programs targeting certain chronic disease risk factors in men; however, future research should consider long-term study designs to assess the efficacy of workplace health programs as a solution to the growing burden of global disease.

Revisiting the impact of Health at Every Size® interventions on health and cardiometabolic related outcomes: An updated systematic review with meta-analysis.

AIMS: To (1) synthesise evidence from Health at Every Size® interventions on physical and psychological health in people with overweight and obesity and (2) report between-group differences within interventions evaluating the impact of Health at Every Size® interventions on health and health-related outcomes. METHODS: Six databases (Medline, Embase, Cochrane, PsychInfo, CINAHL, and Scopus) were searched from inception until November 2022. Included studies were conducted in adults with overweight or obesity, used Health at Every Size®-based interventions compared with control interventions and reported dietary, physical and/or psychological outcomes, including diet quality, anthropometry, or quality of life. Data on between-group differences were extracted. Risk of bias was assessed using ROB2. Random-effects meta-analyses were undertaken for outcomes with at least three studies reporting the same or comparable data. RESULTS: From 128 studies identified, 19 full-text articles (10 unique studies, 6 published since 2017), were included. Meta-analysis found a significant reduction for susceptibility to hunger in Health at Every Size® intervention groups relative to controls (p = 0.005), with no significant difference (p > 0.05) between Health at Every Size® interventions and control groups for anthropometric, psychological or cardiometabolic outcomes (total cholesterol, HDL cholesterol, triglycerides, systolic or diastolic blood pressure). CONCLUSION: Health at Every Size® interventions had similar results compared with weight-based interventions on anthropometric outcomes and cardiometabolic outcomes. Health at Every Size® interventions had a significant benefit for reducing susceptibility to hunger. The decision to use a Health at Every Size®-based intervention should be personalised to individual needs. Further research in more diverse populations is required using standardised outcome measures to facilitate future meta-analyses.

Healthy rural hearts: The feasibility of a telehealth nutrition randomised controlled trial for rural people at risk of cardiovascular disease.

INTRODUCTION: Improving dietary patterns using medical nutrition therapy delivered via telehealth could make an effective contribution to reducing cardiovascular disease burden in rural Australia. However, it is important that medical nutrition therapy programmes are developed in collaboration with rural stakeholders, to increase feasibility for the rural context and the likelihood of successful implementation. The aim of this study was to evaluate the preliminary feasibility outcomes of integration (implementation), practicality, acceptability, demand, and preliminary effectiveness at the 3-month timepoint of the Healthy Rural Hearts randomised control trial. METHODS: Feasibility measures were collected from participants in the Healthy Rural Hearts medical nutrition therapy trial. Study participants were patients from eligible primary care practices who had been assessed by their general practitioner as being at moderate to high risk of developing cardiovascular disease in the next five years. The sample in this analysis includes those who had completed the first 3-months of the study. Feasibility outcomes were measured over the first 3-months of the trial intervention. A process evaluation survey was used to collect measures relating to intervention implementation, practicality, acceptability, and demand. Completion rates of the Australian Eating Survey Heart version, Personalised Nutrition Questionnaire, pathology tests and telehealth medical nutrition therapy consultations delivered by Accredited Practising Dietitians were also used to measure intervention practicality. Preliminary effectiveness was evaluated by comparing the intervention group's dietary change, measured using Australian Eating Survey Heart with data from the control group. RESULTS: A total of 105 participants (75 intervention, 30 control participants) were eligible for inclusion in analysis. Attendance rates at the first 3-months of dietitian consultations ranged from 94.7% to 89.3% between the first and 3-month consultations, and most participants were able to complete the Australian Eating Survey Heart and Personalised Nutrition Questionnaire prior to their initial consultation [Australian Eating Survey Heart (n = 57, 76%) and Personalised Nutrition Questionnaire (n = 61, 81.3%)] and the Australian Eating Survey Heart prior to their 3-month consultation (n = 52, 69.3%). Of the participants who completed a pathology test at the 3-month time-point (n = 54, 72%), less than half were able to do so prior to their dietitian consultation (n = 35, 46.7%). Of the 75 intervention participants, 28 (37.3%) completed the process evaluation survey. Intervention participants ranked acceptability of the Healthy Rural Hearts intervention highly (mean rank out of 10 = 9.5, SD 1.9), but provided mixed responses on whether they would access the intervention outside of the study (mean rank out of 10 = 6.0, SD 3.5). There were statistically significant increases in percentage total energy intake derived from nutrient-dense core foods compared to the control group (p ≤ 0.05). DISCUSSION: The positive findings related to acceptability and implementation outcomes suggest that the Healthy Rural Hearts intervention was acceptable, practical, and able to be implemented within this population living in rural NSW. This, combined with the small to medium effect size in the proportion of total energy derived from nutrient-dense core foods compared to the control group indicates that long-term intervention effectiveness on other cardiovascular disease outcomes is important to evaluate in the future.

Do Precision and Personalised Nutrition Interventions Improve Risk Factors in Adults with Prediabetes or Metabolic Syndrome? A Systematic Review of Randomised Controlled Trials.

This review aimed to synthesise existing literature on the efficacy of personalised or precision nutrition (PPN) interventions, including medical nutrition therapy (MNT), in improving outcomes related to glycaemic control (HbA1c, post-prandial glucose [PPG], and fasting blood glucose), anthropometry (weight, BMI, and waist circumference [WC]), blood lipids, blood pressure (BP), and dietary intake among adults with prediabetes or metabolic syndrome (MetS). Six databases were systematically searched (Scopus, Medline, Embase, CINAHL, PsycINFO, and Cochrane) for randomised controlled trials (RCTs) published from January 2000 to 16 April 2023. The Academy of Nutrition and Dietetics Quality Criteria were used to assess the risk of bias. Seven RCTs (n = 873), comprising five PPN and two MNT interventions, lasting 3-24 months were included. Consistent and significant improvements favouring PPN and MNT interventions were reported across studies that examined outcomes like HbA1c, PPG, and waist circumference. Results for other measures, including fasting blood glucose, HOMA-IR, blood lipids, BP, and diet, were inconsistent. Longer, more frequent interventions yielded greater improvements, especially for HbA1c and WC. However, more research in studies with larger sample sizes and standardised PPN definitions is needed. Future studies should also investigate combining MNT with contemporary PPN factors, including genetic, epigenetic, metabolomic, and metagenomic data.

Genetic influences on circulating retinol and its relationship to human health.

Retinol is a fat-soluble vitamin that plays an essential role in many biological processes throughout the human lifespan. Here, we perform the largest genome-wide association study (GWAS) of retinol to date in up to 22,274 participants. We identify eight common variant loci associated with retinol, as well as a rare-variant signal. An integrative gene prioritisation pipeline supports novel retinol-associated genes outside of the main retinol transport complex (RBP4:TTR) related to lipid biology, energy homoeostasis, and endocrine signalling. Genetic proxies of circulating retinol were then used to estimate causal relationships with almost 20,000 clinical phenotypes via a phenome-wide Mendelian randomisation study (MR-pheWAS). The MR-pheWAS suggests that retinol may exert causal effects on inflammation, adiposity, ocular measures, the microbiome, and MRI-derived brain phenotypes, amongst several others. Conversely, circulating retinol may be causally influenced by factors including lipids and serum creatinine. Finally, we demonstrate how a retinol polygenic score could identify individuals more likely to fall outside of the normative range of circulating retinol for a given age. In summary, this study provides a comprehensive evaluation of the genetics of circulating retinol, as well as revealing traits which should be prioritised for further investigation with respect to retinol related therapies or nutritional intervention.

Diet quality and cardiovascular outcomes: A systematic review and meta-analysis of cohort studies.

AIMS: To evaluate relationships between diet quality and cardiovascular outcomes. METHODS: Six databases were searched for studies published between January 2007 and October 2021. Eligible studies included cohort studies that assessed the relationship between a priori diet quality and cardiovascular disease mortality and morbidity in adults. The Academy of Nutrition and Dietetics Checklist was used to assess the risk of bias. Study characteristics and outcomes were extracted from eligible studies using standardised processes. Data were summarised using risk ratios for cardiovascular disease incidence and mortality with difference compared for highest versus lowest diet quality synthesised in meta-analyses using a random effects model. RESULTS: Of the 4780 studies identified, 159 studies (n = 6 272 676 adults) were included. Meta-analyses identified a significantly lower cardiovascular disease incidence (n = 42 studies, relative risk 0.83, 95% CI 0.82-0.84, p < 0.001) and mortality risk (n = 49 studies, relative risk 0.83, 95% CI 0.82-0.84, p < 0.001) among those with highest versus lowest diet quality. In sensitivity analyses of a high number of pooled studies (≥13 studies) the Mediterranean style diet patterns and adherence to the heart healthy diet guidelines were significantly associated with a risk reduction of 15% and 14% for cardiovascular disease incidence and 17% and 20% for cardiovascular disease mortality respectively (p < 0.05). CONCLUSIONS: Higher diet quality is associated with lower incidence and risk of mortality for cardiovascular disease however, significant study heterogeneity was identified for these relationships.

Dietary Assessment and Metabolomic Methodologies in Human Feeding Studies: A Scoping Review.

Dietary metabolomics is a relatively objective approach to identifying new biomarkers of dietary intake and for use alongside traditional methods. However, methods used across dietary feeding studies vary, thus making it challenging to compare results. The objective of this study was to synthesize methodological components of controlled human feeding studies designed to quantify the diet-related metabolome in biospecimens, including plasma, serum, and urine after dietary interventions. Six electronic databases were searched. Included studies were as follows: 1) conducted in healthy adults; 2) intervention studies; 3) feeding studies focusing on dietary patterns; and 4) measured the dietary metabolome. From 12,425 texts, 50 met all inclusion criteria. Interventions were primarily crossover (n = 25) and parallel randomized controlled trials (n = 22), with between 8 and 395 participants. Seventeen different dietary patterns were tested, with the most common being the "High versus Low-Glycemic Index/Load" pattern (n = 11) and "Typical Country Intake" (n = 11); with 32 providing all or the majority (90%) of food, 16 providing some food, and 2 providing no food. Metabolites were identified in urine (n = 31) and plasma/serum (n = 30). Metabolites were quantified using liquid chromatography, mass spectroscopy (n = 31) and used untargeted metabolomics (n = 37). There was extensive variability in the methods used in controlled human feeding studies examining the metabolome, including dietary patterns tested, biospecimen sample collection, and metabolomic analysis techniques. To improve the comparability and reproducibility of controlled human feeding studies examining the metabolome, it is important to provide detailed information about the dietary interventions being tested, including information about included or restricted foods, food groups, and meal plans provided. Strategies to control for individual variability, such as a crossover study design, statistical adjustment methods, dietary-controlled run-in periods, or providing standardized meals or test foods throughout the study should also be considered. The protocol for this review has been registered at Open Science Framework (https://doi.org/10.17605/OSF.IO/DAHGS).

Dietary metabolome profiles of a Healthy Australian Diet and a Typical Australian Diet: protocol for a randomised cross-over feeding study in Australian adults.

INTRODUCTION: Traditional dietary assessment methods such as 24-hour recalls and food frequency questionnaires rely on self-reported data and are prone to error, bias and inaccuracy. Identification of dietary metabolites associated with different dietary patterns can provide objective markers of whole diet patterns that account for metabolism and individual responses to dietary interventions. Additionally, few studies have investigated country-specific healthy and unhealthy dietary patterns using metabolomics. Therefore, the current study aims to identify urinary and plasma metabolites that characterise a 'healthy' (aligned with current national dietary guidelines) and an 'unhealthy' dietary pattern (Typical Australian Diet) in Australian adults. METHODS AND ANALYSIS: The Diet Quality Feeding Study (DQFS) is an 8-week cross-over feeding study that will recruit 40 healthy adults from the Hunter region (NSW, Australia). Data collected includes biospecimens (whole blood, urine, stool) for quantification of dietary metabolite biomarkers; questionnaires (medical history/demographic, physical activity, quality of life); physical measures (anthropometry, body composition, waist circumference, blood pressure, arterial pressure); skin carotenoids and dietary intake (24-hour recalls, food frequency questionnaire). Participants will attend the research facility every 2 weeks (end of the run-in, each diet intervention and washout period) for collection of physical measures. All food will be provided to participants for each dietary intervention period, and participants will return to their usual diet during the run-in and washout periods. Targeted and untargeted metabolomics using liquid chromatography-mass spectrometry and/or proton nuclear magnetic resonance (1H-NMR) spectroscopy will be used to identify metabolites in biospecimens associated with dietary intake. ETHICS AND DISSEMINATION: This study is approved by the Hunter New England Human Research Ethics Committee (HNEHREC; 2022/ETH01649) and the University of Newcastle's Human Research Ethics Committee (HREC; H-2022-0330). Findings will be disseminated to study participants, funding bodies supporting the DQFS, peer-review publications and presented at scientific conferences within the field of research. TRIAL REGISTRATION NUMBER: Australian New Zealand Clinical Trials Registry (ACTRN12622001321730).

Red Blood Cell Membrane Fatty Acid Composition, Dietary Fatty Acid Intake and Diet Quality as Predictors of Inflammation in a Group of Australian Adults.

Evidence suggests that diet can play a role in modulating systemic inflammation. This study aims to examine the relationship between fatty acids (FAs) (self-reported dietary intake and red blood cell (RBC) membrane fatty acid concentrations), three diet quality scores, and the plasma concentrations of inflammatory markers (interleukin-6, IL-6; tumour necrosis factor alpha, TNF-α; and C-reactive protein, CRP) in a group of Australian adults (n = 92). Data were collected on their demographic characteristics, health status, supplement intake, dietary intake, RBC-FAs and plasma inflammatory markers over a nine-month period. Mixed-effects models were used to determine the relationship between RBC-FAs, dietary intake of FAs, diet quality scores and inflammatory markers to determine which variable most strongly predicted systemic inflammation. A significant association was identified between dietary saturated fat intake and TNF-α (ß = 0.01, p < 0.05). An association was also identified between RBC membrane saturated fatty acids (SFA) and CRP (ß = 0.55, p < 0.05). Inverse associations were identified between RBC membrane monounsaturated fatty acids (MUFAs) (ß = -0.88, p < 0.01), dietary polyunsaturated fatty acids (PUFAs) (ß = -0.21, p < 0.05) and CRP, and the Australian Eating Survey Modified Mediterranean Diet (AES-MED) score and IL-6 (ß = -0.21, p < 0.05). In summary, using both objective and subjective measures of fat intake and diet quality, our study has confirmed a positive association between saturated fat and inflammation, while inverse associations were observed between MUFAs, PUFAs, the Mediterranean diet, and inflammation. Our results provide further evidence that manipulating diet quality, in particular fatty acid intake, may be useful for reducing chronic systemic inflammation.