Real world evidence on the characteristics of regular and intermittent users of a very-low calorie diet program and associations with measures of program success, health, and quality of life.

Background: Very low-calorie diet (VLCD) programs are readily available in Australia. However, there is a lack of real-world evidence describing the characteristics related to positive outcomes. Aims: To examine the demographic, eating, self-efficacy and program engagement characteristics of VLCD users in Australia, and the associations between user characteristics and program success, weight loss, quality of life (QOL) and health. Method: Cross-sectional data from Australian adults: regular users (n = 189: VLCD user ≥4 days/week for >4 weeks) and intermittent users (n = 111, VLCD user <4 weeks and/or <4 days/week). Self-reported data on demographics, VLCD program use, support, eating behavior, weight-related QOL, mental health, physical health, self-efficacy, and physical activity. Descriptive and inferential statistics were performed in R. Results: Compared to regular users, intermittent users reported lower percentage weight loss (15.1% ± SD 9.8 vs. 9.9% ± SD 6.8, relative to starting weight), fewer reported their VLCD program as very successful (44% vs. 35%), higher depressive symptom scores (8.7 ± SD 2.8 vs. 6.7 ± SD 5.1), and lower general self-efficacy (23.9 ± SD 4.7 vs. 29.4 ± SD 5.7), nutrition self-efficacy (11.9 ± SD 2.0 vs. 14.5 ± SD 3.1) and weight-related QOL scores (60.9 ± SD 22.2 vs. 65.0 ± SD 11.8; p < 0.001 for all). In regular users, older age and longer program duration were associated with greater total weight loss, support, and program success (p < 0.001 for all). In intermittent users, program success was greater when dietitian support was used (odds ratio [OR] 6.50) and for those with higher BMIs (OR 1.08, p < 0.001 for all). In both groups, more frequent support was associated with better weight-related QOL (p < 0.001). Conclusion: This study provides real-world evidence that regular VLCD users had greater success and weight loss than intermittent program users. These findings may be used to tailor and improve the delivery of VLCD programs in Australia and other countries with retail access to VLCDs.

Should We 'Eat a Rainbow'? An Umbrella Review of the Health Effects of Colorful Bioactive Pigments in Fruits and Vegetables.

Health promotion campaigns have advocated for individuals to 'eat a rainbow' of fruits and vegetables (FV). However, the literature has only focused on individual color pigments or individual health outcomes. This umbrella review synthesized the evidence on the health effects of a variety of color-associated bioactive pigments found in FV (carotenoids, flavonoids, betalains and chlorophylls), compared to placebo or low intakes. A systematic search of PubMed, EMBASE, CINAHL and CENTRAL was conducted on 20 October 2021, without date limits. Meta-analyzed outcomes were evaluated for certainty via the GRADE system. Risk of bias was assessed using the Centre for Evidence-Based Medicine critical appraisal tools. A total of 86 studies were included, 449 meta-analyzed health outcomes, and data from over 37 million participants were identified. A total of 42% of health outcomes were improved by color-associated pigments (91% GRADE rating very low to low). Unique health effects were identified: n = 6 red, n = 10 orange, n = 3 yellow, n = 6 pale yellow, n = 3 white, n = 8 purple/blue and n = 1 green. Health outcomes associated with multiple color pigments were body weight, lipid profile, inflammation, cardiovascular disease, mortality, type 2 diabetes and cancer. Findings show that color-associated FV variety may confer additional benefits to population health beyond total FV intake.

Methodology for the Review and Update of Nutrient Criteria Underpinning Front-of-Pack Labeling: Application to the Glycemic Index Symbol.

Background: Nutrient criteria underlying front-of-pack food labeling programs can play an important role in improving dietary intakes. Currently, no methodology for the development or update of nutrient criteria has been published, nor the methods used by food regulatory bodies. The scientific publication of methodology outlining the development and update of nutrient criteria underpinning front-of-pack food labeling programs highlighting healthier food choices is needed. Objective: To develop and provide a globally applicable and transparent methodology for researchers to follow when reviewing existing or developing new nutrient criteria for front-of-pack labeling. Methods: The Nutrient Criteria Methodology involved five phases: Phase I, the development of guiding principles; Phase II, collection of information for subsequent phases, including a pre-scope of the literature and selection of food composition database(s) for modeling; Phase III, literature review of all possible nutrients relevant to the nutrient criteria; Phase IV, database modeling to set quantitative limits for each selected nutrient; Phase V, assessment of the criteria against an established nutritional quality assessment tool. As an example, the methodology was applied to the update of the GI Symbol Product Eligibility and Nutrient Criteria (PENC). Results: A comprehensive and replicable methodology, based on best practice protocols and ensuring both scientific credibility and practicality of use by industry, was developed. Application of the five phases of the methodology to the GI Symbol PENC highlighted the ability of the methodology to uncover nutritional measures currently missing in many nutrient criteria for front-of-pack food labeling programs and other national food labeling systems, such as glycemic load and the unsaturated to saturated fat ratio. Foods achieving the PENC had a higher Health Star Rating than foods not achieving the PENC. Conclusion: Our Nutrient Criteria Methodology can be applied to the development and update of global nutrient criteria underpinning front-of-pack food labeling programs. Further research into the implementation of additional nutritional measures found to be important for human health is recommended, with the goal of the prevention of diet-related disease.

How should we judge edible oils and fats? An umbrella review of the health effects of nutrient and bioactive components found in edible oils and fats.

Dietary guidelines for many Western countries base their edible oil and fat recommendations solely on saturated fatty acid content. This study aims to demonstrate which nutritional and bioactive components make up commonly consumed edible oils and fats; and explore the health effects and strength of evidence for key nutritional and bioactive components of edible oils. An umbrella review was conducted in several stages. Food composition databases of Australia and the United States of America, and studies were examined to profile nutrient and bioactive content of edible oils and fats. PUBMED and Cochrane databases were searched for umbrella reviews, systematic literature reviews of randomized controlled trials or cohort studies, individual randomized controlled trials, and individual cohort studies to examine the effect of the nutrient or bioactive on high-burden chronic diseases (cardiovascular disease, type 2 diabetes mellitus, obesity, cancer, mental illness, cognitive impairment). Substantial systematic literature review evidence was identified for fatty acid categories, tocopherols, biophenols, and phytosterols. Insufficient evidence was identified for squalene. The evidence supports high mono- and polyunsaturated fatty acid compositions, total biophenol content, phytosterols, and possibly high α-tocopherol content as having beneficial effects on high-burden health comes. Future dietary guidelines should use a more sophisticated approach to judge edible oils beyond saturated fatty acid content.

Nutrient Dense, Low-Cost Foods Can Improve the Affordability and Quality of the New Zealand Diet-A Substitution Modeling Study.

The high prevalence of non-communicable disease in New Zealand (NZ) is driven in part by unhealthy diet selections, with food costs contributing to an increased risk for vulnerable population groups. This study aimed to: (i) identify the nutrient density-to-cost ratio of NZ foods; (ii) model the impact of substituting foods with a lower nutrient density-to-cost ratio with those with a higher nutrient density-to-cost ratio on diet quality and affordability in representative NZ population samples for low and medium socioeconomic status (SES) households by ethnicity; and (iii) evaluate food processing level. Foods were categorized, coded for processing level and discretionary status, analyzed for nutrient density and cost, and ranked by nutrient density-to-cost ratio. The top quartile of nutrient dense, low-cost foods were 56% unprocessed (vegetables, fruit, porridge, pasta, rice, nuts/seeds), 31% ultra-processed (vegetable dishes, fortified bread, breakfast cereals unfortified <15 g sugars/100 g and fortified 15-30 g sugars/100 g), 6% processed (fruit juice), and 6% culinary processed (oils). Using substitution modeling, diet quality improved by 59% and 71% for adults and children, respectively, and affordability increased by 20-24%, depending on ethnicity and SES. The NZ diet can be made healthier and more affordable when nutritious, low-cost foods are selected. Processing levels in the healthier, modeled diet suggest that some non-discretionary ultra-processed foods may provide a valuable source of low-cost nutrition for food insecure populations.

Anti-inflammatory effects of oral supplementation with curcumin: a systematic review and meta-analysis of randomized controlled trials.

CONTEXT: Chronic inflammation is a major contributor to the development of noncommunicable diseases. Curcumin, a bioactive polyphenol from turmeric, is a well-known anti-inflammatory agent in preclinical research. Clinical evidence remains inconclusive because of discrepancies regarding optimal dosage, duration, and formulation of curcumin. OBJECTIVE: The aim of this systematic review, conducted and reported in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and checklist, was to evaluate the efficacy of curcumin supplementation on systemic inflammatory mediators, comparing dose, duration, and bioavailability status of interventions. DATA SOURCES: The Medline, CINAHL, EMBASE, Scopus, and Cochrane literature databases were searched from 1980 to May-end 2019. Randomized controlled trials investigating effects of dietary curcumin on inflammatory mediators in humans not receiving anti-inflammatory treatment were eligible for inclusion. Two authors independently assessed titles and abstracts of identified articles for potential eligibility and respective, retrieved, full-text articles; disagreements were resolved by a third author. Evidence quality was critically appraised using the Quality Criteria Checklist for Primary Research. DATA EXTRACTION: Thirty-two trials (N = 2,038 participants) were included and 28 were meta-analyzed using a random-effects model; effect sizes were expressed as Hedges' g (95%CI). DATA ANALYSIS: Pooled data (reported here as weighted mean difference [WMD]; 95%CI) showed a reduction in C-reactive protein (-1.55 mg/L; -1.81 to -1.30), interleukin-6 (-1.69 pg/mL, -2.56 to -0.82), tumor necrosis factor α (-3.13 pg/mL; -4.62 to -1.64), IL-8 (-0.54 pg/mL; -0.82 to -0.28), monocyte chemoattractant protein-1 (-2.48 pg/mL; -3.96 to -1.00), and an increase in IL-10 (0.49 pg/mL; 0.10 to 0.88), with no effect on intracellular adhesion molecule-1. CONCLUSION: These findings provide evidence for the anti-inflammatory effects of curcumin and support further investigation to confirm dose, duration, and formulation to optimize anti-inflammatory effects in humans with chronic inflammation. SYSTEMATIC REVIEW REGISTRATION: PROSPERO registration no. CRD42019148682.

Diet and Economic Modelling to Improve the Quality and Affordability of the Australian Diet for Low and Medium Socioeconomic Households.

Food costs are a barrier to healthier diet selections, particularly for low socioeconomic households who regularly choose processed foods containing refined grains, added sugars, and added fats. In this study, the objectives were to: (i) identify the nutrient density-to-cost ratio of Australian foods; (ii) model the impact of substituting foods with lower nutrient density-to-cost ratio with those with the highest nutrient density-to-cost ratio for diet quality and affordability in low and medium socioeconomic households; and (iii) evaluate food processing levels. Foods were categorized, coded for processing level, analysed for nutrient density and cost, and ranked by nutrient density-to-cost ratio. The top quartile of nutrient dense, low-cost foods included 54% unprocessed (vegetables and reduced fat dairy), 33% ultra-processed (fortified wholegrain bread and breakfast cereals <20 g sugars/100 g), and 13% processed (fruit juice and canned legumes). Using substitution modelling, diet quality improved by 52% for adults and 71% for children across all households, while diet affordability improved by 25% and 27% for low and medium socioeconomic households, respectively. The results indicate that the quality and affordability of the Australian diet can be improved when nutritious, low-cost foods are selected. Processing levels in the healthier modelled diets suggest that some ultra-processed foods may provide a beneficial source of nutrition when consumed within national food group recommendations.

Choosing and following a very low calorie diet program in Australia: A quasi-mixed methods study to understand experiences, barriers, and facilitators in a self-initiated environment.

AIM: In Australian adults, this study seeks to describe the experiences and factors associated with the perceived outcomes of using a very low calorie diet (VLCD) program for ≥4 weeks. METHODS: A mixed method study using the method perspective was conducted to analyse individual semi-structured interviews conducted via videoconference and cross-sectional survey data. Australians 18 to 65 years were eligible if they were currently consuming at least one VLCD product daily for ≥4 weeks or had ceased consumption within 4 weeks. Interviews were thematically analysed. RESULTS: Weight loss (19 kg [SD: 18 kg]) and duration (5 months [SD: 5 months]) of VLCD product use of the 31 participants (female: 97%, 44 [SD: 11] years, body mass index >30 kg/m2 : 84%) were strongly correlated (r = 0.73, P < .001). Participants' experiences were influenced by a journey of learning from their previous weight loss attempts, discerned the VLCD program as credible, and chose to commence the VLCD due to a convergence of internal motivators. Early health-related outcomes were a reinforcing stimulus and participants developed new health behaviours but felt dependent on the VLCD long term. Throughout these experiences the participants identified various individual, program structure, and environment related factors which either facilitated their VLCD program use or created barriers to achieving their goals. Health care professionals were minimally engaged. CONCLUSIONS: A model of care to support facilitators and overcome barriers would mean more meaningful engagement of health care professionals to ultimately improve the experience and adherence of the VLCD program users in Australia.

Dietary supplementation with docosahexaenoic acid rich fish oil increases circulating levels of testosterone in overweight and obese men.

Pre-clinical evidence suggests that omega-3 (n-3) polyunsaturated fatty acids (PUFAs), in particular, docosahexaenoic acid (DHA) have been shown to affect testosterone synthesis in males. This study is a secondary analysis of a randomized controlled trial which determined the effect of a DHA-enriched fish oil supplement on insulin resistance. The aim of the current study was to determine whether testosterone levels change in response to a DHA-enriched fish oil intervention. Overweight and obese men and women without diabetes were recruited to the study. Participants were stratified by sex and randomly allocated to intervention (860 mg DHA + 120 g EPA/day; FO) or an isocaloric control (corn oil; CO) for 12 weeks. A fasted blood sample was collected pre- and post-intervention. Fatty acid composition of erythrocyte membranes was measured using gas chromatography. Total testosterone and metabolic parameters were measured by an accredited commercial pathology laboratory. Sixty-one participants (CO/FO: n = 29/32) were included in the current analysis (male: n = 22, 36.07%).  DHA-enriched fish oil supplementation increased total testosterone levels in males after adjusting for baseline levels, age and BMI. There was no treatment effect in females. Changes in testosterone levels in males were positively associated with changes to omega-3 PUFAs EPA and DHA and inversely correlated with omega-6 PUFA, arachidonic acid and dihomo-gamma-linolenic acid content in erythrocyte membranes, and was associated with beneficial changes to fasting insulin and HOMA-IR across the course of the study. DHA-enriched fish oil supplementation increases testosterone levels in overweight and obese men. Further research is warranted to substantiate these findings with a larger sample size and a longer follow-up period.

The Effect of Replacing Refined Grains with Whole Grains on Cardiovascular Risk Factors: A Systematic Review and Meta-Analysis of Randomized Controlled Trials with GRADE Clinical Recommendation.

BACKGROUND: Observational data have established a link between the consumption of whole grains and reduced risk of cardiovascular disease (CVD); however, there is a need to review interventional research. OBJECTIVE: Our aim was to determine whether interventions providing whole grain or whole pseudo-grain for dietary consumption improved CVD-related outcomes compared with refined grain or placebo in adults with or without chronic disease and/or associated risk factors. METHODS: A systematic review and meta-analysis of randomized controlled trials that compared whole-grain vs refined-grain or placebo consumption by human adults was conducted. PubMed, CINAHL, Embase, Web of Science, and Cochrane CENTRAL were searched for studies of 12 weeks (or 2 weeks for inflammatory outcomes) duration until 21 February 2020. Data were extracted for 14 types of CVD risk factors (40 outcomes in total). Risk of bias was assessed using the Cochrane Risk-of-Bias tool. Meta-analysis was performed using Comprehensive Meta-Analysis software. The Grading of Recommendations Assessment, Development and Evaluation method was used to determine confidence in the pooled effects and to inform a clinical recommendation. RESULTS: Twenty-five randomized controlled trials were included and 22 were meta-analyzed. Interventions ranged from 2 to 16 weeks; most samples were healthy (n = 13 studies) and used mixed whole grains (n = 11 studies). Meta-analysis found that whole-grain oats improved total cholesterol (standardized mean difference [SMD] = -0.54, 95% CI -0.95 to -0.12) and low-density lipoprotein cholesterol (SMD = -0.57, 95% CI -0.84 to -0.31), whole-grain rice improved triglycerides (SMD = 0.22, 95% CI -0.44 to -0.01), and whole grains (all types) improved hemoglobin A1c (SMD = -0.33, 95% CI -0.61 to -0.04) and C-reactive protein (SMD = -0.22, 95% CI -0.44 to -0.00). CONCLUSIONS: For adults with or without CVD risk factors, consuming whole grains as opposed to refined grains can improve total cholesterol, low-density lipoprotein cholesterol, hemoglobin A1c, and C-reactive protein. There is insufficient evidence to recommend the whole grains as opposed to refined grains for the prevention and treatment of CVD. Further interventional research is needed to better understand the preventive and treatment potential of whole-grain and whole pseudo-grain dietary intake for cardiovascular disease, particularly among those with existing CVD risk factors.

Examining the health effects and bioactive components in Agaricus bisporus mushrooms: a scoping review.

There is evidence from both in vitro and animal models that the consumption of edible mushrooms has beneficial effects on health. It is unclear whether similar effects exist in humans and which bioactive compounds are present. This review synthesises the evidence on the world's most commonly consumed mushroom, Agaricus bisporus to (i) examine its effect on human health outcomes; and (ii) determine the nutrient density of its bioactive compounds, which may explain their health effects. A systematic literature search was conducted on the consumption of A. bisporus, without date and study design limits. Bioactive compounds included ergosterol, ergothioneine, flavonoids, glucans and chitin. Two authors independently identified studies for inclusion and assessed methodological quality. Beneficial effects of A. bisporus on metabolic syndrome, immune function, gastrointestinal health and cancer, with the strongest evidence for the improvement in Vitamin D status in humans, were found. Ultraviolet B (UVB) exposed mushrooms may increase and maintain serum 25(OH)D levels to a similar degree as vitamin D supplements. A. bisporus contain beta-glucans, ergosterol, ergothioneine, vitamin D and an antioxidant compound usually reported as flavonoids; with varying concentrations depending on the type of mushroom, cooking method and duration, and UVB exposure. Further research is required to fully elucidate the bioactive compounds in mushrooms using vigorous analytical methods and expand the immunological markers being tested. To enable findings to be adopted into clinical practice and public health initiatives, replication of existing studies in different population groups is required to confirm the impact of A. bisporus on human health.

Docosahexaenoic Acid-Rich Fish Oil Supplementation Reduces Kinase Associated with Insulin Resistance in Overweight and Obese Midlife Adults.

Targeting kinases linked to insulin resistance (IR) and inflammation may help in reducing the risk of type 2 diabetes (T2D) and Alzheimer's disease (AD) in its early stages. This study aimed to determine whether DHA-rich fish oil supplementation reduces glycogen synthase kinase (GSK-3), which is linked to both IR and AD. Baseline and post-intervention plasma samples from 58 adults with abdominal obesity (Age: 51.7 ± 1.7 years, BMI: 31.9 ± 0.8 kg/m2) were analysed for outcome measures. Participants were allocated to 2 g DHA-rich fish oil capsules (860 mg DHA + 120 mg EPA) (n = 31) or placebo capsules (n = 27) per day for 12 weeks. Compared to placebo, DHA-rich fish oil significantly reduced GSK-3ß by -2.3 ± 0.3 ng/mL. An inverse correlation (p < 0.05) was found between baseline insulin and IR and their changes following intervention only in participants with C-reactive protein levels higher than 2.4 mg/L. DHA-rich fish oil reduces GSK-3 and IR, suggesting a potential role of long-chain omega-3 polyunsaturated fatty acids (LCn-3PUFA) in ameliorating AD risk.

Association between plasma phospholipid omega-3 polyunsaturated fatty acids and type 2 diabetes is sex dependent: The Hunter Community Study.

BACKGROUND & AIMS: Chronic inflammation drives the development of insulin resistance and type 2 diabetes. Long-chain omega-3 polyunsaturated fatty acids (LCn-3PUFA) eicosapentaenoic acid (EPA, c20:5n-3) and docosahexaenoic acid (DHA, c22:6n-3) may protect against type 2 diabetes development. The aim of this current study is to determine whether LCn-3PUFA status is associated with type 2 diabetes in the Hunter Community Study. METHODS: Men and women aged 55-85 years were randomly selected from the electoral roll and invited to participate. Participants were included in the current study if they had plasma phospholipid fatty acid composition data available and diabetes status could be determined. LCn-3PUFA status was determined by fatty acid composition of plasma phospholipids (EPA + DHA, %,w/w). Diabetes was determined according to World Health Organisation criteria. Insulin was measured in n = 251 participants and HOMA-IR calculated. RESULTS: In total, n = 2092 (diabetes: n = 249) participants were included. After adjusting for confounders of diabetes, LCn-3PUFA status was inversely associated with diabetes in overweight/obese females (OR [95%CI]: 0.90 [0.80, 1.00], p = 0.045) but not males (p-interactionsex = 0.041). Overweight/obese females with diabetes had significantly lower levels of DHA than those without diabetes (mean difference [95%CI]: -0.53 [-0.87, -0.20], p = 0.002), with no difference in EPA. LCn-3PUFA was inversely associated with HOMA-IR (r = -0.175, p = 0.005). CONCLUSIONS: This study provides further evidence of a sex-dependent association between LCn-3PUFA and type 2 diabetes. Causal pathways between LCn-3PUFA and type 2 diabetes merits delineation.

Long-chain omega-3 polyunsaturated fatty acids and cognitive decline in non-demented adults: a systematic review and meta-analysis.

CONTEXT: Long-chain omega-3 polyunsaturated fatty acids (LCn-3PUFAs) are widely considered as nootropic agents that may be beneficial in reversing cognitive impairment. OBJECTIVE: The present systematic review of randomized controlled trials was conducted to determine the changes in cognitive function after intervention with LCn-3PUFA supplementation in non-demented adults, including those with mild cognitive impairment. DATA SOURCES: Five databases (MEDLINE, CINAHL, Scopus, EMBASE, and the Cochrane Library) were searched systematically along with reference lists of selected articles. STUDY SELECTION: Studies were eligible for inclusion if they measured the effect of LCn-3PUFA supplementation on cognition in non-demented adults. DATA EXTRACTION: A total of 787 records were screened, of which 25 studies were eligible for inclusion. Treatment effects were summarized as global cognitive function for primary outcome and measured using the Mini-Mental State Examination and individual cognitive domains for secondary outcome. The pooled effect sizes were estimated using Hedge's g and random-effects modeling. DATA ANALYSIS: Results from randomized controlled trials indicate that LCn-3PUFAs have no effect on global cognitive function (Hedge's g = 0.02; 95% confidence interval, -0.12 to 0.154), and among the specific cognitive domains, only memory function showed a mild benefit (Hedge's g = 0.31; P = 0.003; z = 2.945). CONCLUSION: The existing literature suggests that LCn-3PUFA supplementation could provide a mild benefit in improving memory function in non-demented older adults. SYSTEMATIC REVIEW REGISTRATION: PROSPERO registration no. CRD42017078664.

Modulation of Circulating Trimethylamine N-Oxide Concentrations by Dietary Supplements and Pharmacological Agents: A Systematic Review.

Discovery of the association of plasma/serum trimethylamine N-oxide (TMAO) concentrations with atherosclerosis has sparked immense interest in exploring TMAO as a predictor of cardiovascular disease risk. A spectrum of antibiotics and other therapeutic strategies have been employed to test their potential to modulate TMAO concentrations, assuming the gut microbiome to be the key source of TMAO. The aim of this systematic review was to determine whether dietary supplements or pharmacological agents affect TMAO concentrations in adults. Six databases were searched (Medline, EMBASE, CINAHL, Scopus, ProQuest, and PubMed) for randomized and nonrandomized controlled trials. Searches were limited to the English language and to studies in adults. Thirteen eligible trials were identified, including 6 studies on dietary supplements and 7 on pharmacological agents. Whereas intervention studies involving dietary supplements were mostly randomized controlled trials, those involving pharmacological agents appeared opportunistic and varied greatly in study design and duration. Different interventional products were tested, and the studies lacked the consistency to reliably synthesize any evidence for the modifiability of TMAO concentrations by dietary supplements or pharmacological agents. Choline and l-carnitine are conditionally essential nutrients, and carefully designed placebo-controlled randomized trials specifically aimed at reducing the synthesis of microflora-dependent TMAO production from choline-containing precursors by pro- and/or prebiotics, antibiotics, or other pharmaceutical agents may be the way forward for future research.

Differential effects of medium- and long-chain saturated fatty acids on blood lipid profile: a systematic review and meta-analysis.

Background: Medium-chain saturated fatty acids (MCFAs) may affect circulating lipids and lipoproteins differently than long-chain saturated fatty acids (LCSFAs), but the results from human intervention trials have been equivocal. Objective: The aim of this study was to determine whether MCFAs and LCSFAs have differential impacts on blood lipids and lipoproteins. Design: Five databases were searched (EMBASE, MEDLINE, CINAHL, Cochrane, and Scopus) until April 2018, and published clinical trials investigating the differential effects of dietary MCFAs and LCSFAs on blood lipids were included. Searches were limited to the English language and to studies with adults aged >18 y. Where possible, studies were pooled for meta-analysis using RevMan 5.2. The principle summary measure was the mean difference between groups calculated using the random-effects model. Results: Eleven eligible crossover and 1 parallel trial were identified with a total of 299 participants [weighted mean ± SD age: 38 ± 3 y; weighted mean ± SD body mass index (kg/m2): 24 ± 2]. All studies were pooled for the meta-analysis. Diets enriched with MCFAs led to significantly higher high-density lipoprotein (HDL) cholesterol concentrations than diets enriched with LCSFAs (0.11 mmol/L; 95% CI: 0.07, 0.15 mmol/L) with no effect on triglyceride, low-density lipoprotein (LDL) cholesterol, and total cholesterol concentrations. Consumption of diets rich in MCFAs significantly increased apolipoprotein A-I (apoA-I) concentrations compared with diets rich in LCSFAs (0.08 g/L; 95% CI: 0.02, 0.14 g/L). There was no evidence of statistical heterogeneity for HDL cholesterol, apoA-I, and triglyceride concentrations; however, significant heterogeneity was observed for the total cholesterol (I2 = 49%) and LDL cholesterol analysis (I2 = 58%). Conclusion: The findings of this research demonstrate a differential effect of MCFAs and LCSFAs on HDL cholesterol concentrations. Further investigations are warranted to elucidate the mechanism by which the lipid profile is altered. This trial was registered at www.crd.york.ac.uk/PROSPERO as CRD42017078277.

Curcumin alleviates postprandial glycaemic response in healthy subjects: A cross-over, randomized controlled study.

In the current study, we aimed to evaluate the effects of a single dose of curcumin and/or fish oil on postprandial glycaemic parameters in healthy individuals. This was a randomised, placebo-controlled and crossover study. Sixteen (n = 16) volunteers were randomised to receive placebo, curcumin (180 mg) tablets, fish oil (1.2 g long chain omega-3 polyunsaturated fatty acids) capsules and curcumin + fish oil prior to a standard meal on 4 test days separated by a week. Blood glucose, serum insulin and triglycerides were measured at intervals between 0-120 min. Difference between the treatments was measured using two-way repeated measures analysis of variance and pair-wise comparisons using Wilcoxon signed-rank or paired t-test as appropriate. Postprandial glucose concentrations were significantly lower in the curcumin (60.6%, P = 0.0007) and curcumin + fishoil group (51%, P = 0.002) groups at 60 min from baseline. Compared with placebo, area under the curve (AUC) for change in blood glucose concentration was reduced by curcumin (36%, P = 0.003) and curcumin + fishoil (30%, 0.004), but not fish oil alone (p = 0.105). Both curcumin (P = 0.01) and curcumin + fishoil (P = 0.03) treatments significantly lowered postprandial insulin (AUC) by 26% in comparison with placebo. Curcumin, but not fish oil, reduces postprandial glycaemic response and insulin demand for glucose control.

Science behind the cardio-metabolic benefits of omega-3 polyunsaturated fatty acids: biochemical effects vs. clinical outcomes.

Lower incidence of cardiovascular disease (CVD) in the Greenland Inuit, Northern Canada and Japan has been attributed to their consumption of seafood rich in long chain omega-3 polyunsaturated fatty acids (LCn-3PUFA). While a large majority of pre-clinical and intervention trials have demonstrated heart health benefits of LCn-3PUFA, some studies have shown no effects or even negative effects. LCn-3PUFA have been shown to favourably modulate blood lipid levels, particularly a reduction in circulating levels of triglycerides. High density lipoprotein-cholesterol (HDL-C) levels are elevated following dietary supplementation with LCn-3PUFA. Although LCn-3PUFA have been shown to increase low-density lipoprotein-cholesterol (LDL-C) levels, the increase is primarily in the large-buoyant particles that are less atherogenic than small-dense LDL particles. The anti-inflammatory effects of LCn-3PUFA have been clearly outlined with inhibition of NFkB mediated cytokine production being the main mechanism. In addition, reduction in adhesion molecules (intercellular adhesion molecule, ICAM and vascular cell adhesion molecule 1, VCAM-1) and leukotriene production have also been demonstrated following LCn-3PUFA supplementation. Anti-aggregatory effects of LCn-3PUFA have been a subject of controversy, however, recent studies showing sex-specific effects on platelet aggregation have helped resolve the effects on hyperactive platelets. Improvements in endothelium function, blood flow and blood pressure after LCn-3PUFA supplementation add to the mechanistic explanation on their cardio-protective effects. Modulation of adipose tissue secretions including pro-inflammatory mediators and adipokines by LCn-3PUFA has re-ignited interest in their cardiovascular health benefits. The aim of this narrative review is to filter out the reasons for possible disparity between cohort, mechanistic, pre-clinical and clinical studies. The focus of the article is to provide possible explanation for the observed controversies surrounding heart health benefits of LCn-3PUFA.

InsuTAG: A novel physiologically relevant predictor for insulin resistance and metabolic syndrome.

The aim of this study was to investigate whether a novel physiologically relevant marker, InsuTAG (fasting insulin × fasting triglycerides) can predict insulin resistance (IR) and metabolic syndrome (MetS). Data of 618 participants from the Retirement Health and Lifestyle Study (RHLS) were evaluated for the current study. IR was defined by homeostatic model assessment (HOMA-IR) scores. Pearson correlations were used to examine the associations of InsuTAG with HOMA-IR and other markers. Predictions of IR from InsuTAG were evaluated using multiple regression models. Receiver operating characteristic curves (ROC) were constructed to measure the sensitivity and specificity of InsuTAG values and to determine the optimum cut-off point for prediction of IR. InsuTAG was positively correlated with HOMA-IR (r = 0.86; p < 0.0001). InsuTAG is a strong predictor of IR accounting for 65.0% of the variation in HOMA-IR values after adjusting for potential confounders. Areas under the ROC curve showed that InsuTAG (0.93) has higher value than other known lipid markers for predicting IR, with a sensitivity and specificity of 84.15% and 86.88%. Prevalence of MetS was significantly (p < 0.0001) higher in subjects with InsuTAG values greater than optimal cut-off value of 11.2. Thus, InsuTAG appears to be a potential feasible marker of IR and metabolic syndrome.

Curcumin and long-chain Omega-3 polyunsaturated fatty acids for Prevention of type 2 Diabetes (COP-D): study protocol for a randomised controlled trial.

BACKGROUND: Lifestyle interventions, including increase in physical activity and dietary counselling, have shown the ability to prevent type 2 diabetes (T2D) in high-risk state individuals, but the prevalence is still skyrocketing in Australia, in line with global prevalence. Currently, no medicines are approved by the Therapeutic Goods Administration in Australia for the management of prediabetes. Therefore, there is a need of developing a safer, biologically efficacious and cost-effective alternative for delaying the transition of individual health state from prediabetes into T2D. In the current trial we propose to evaluate the effects of curcumin and/or long-chain omega-3 polyunsaturated fatty acids on improving glycosylated haemoglobin as a primary outcome, along with secondary outcomes of glycaemic indices, lipid profile and inflammatory parameters. METHODS/DESIGN: Eighty individuals diagnosed with prediabetes, aged between 30 and 70 years, will be randomly assigned to double placebo, curcumin alone, fish oil alone or double active groups according to a computer-generated randomisation sequence for 12 weeks. At baseline and post-intervention visits participants will be asked to provide blood samples and undergo body composition measurements. A blood sample is used for estimating glycaemic profiles, lipid profiles and inflammatory parameters (C-reactive protein, whole blood cell count, adiponectin, leptin, interleukin-6). The interim visit includes review on compliance with supplements based on capsule log and capsule count, adverse events and anthropometric measurements. In addition to these procedures, participants provide self-reported questionnaires on dietary intake (using a 3-day food record), a physical activity questionnaire and medical history. DISCUSSION: This trial aims to determine whether curcumin and/or long-chain omega-3 polyunsaturated fatty acids affect surrogate markers of glycaemic control which is relevant to delaying T2D. To date 38 participants completed the trial. No changes have been made to the clinical protocol post recruitment. If successful, this trial will provide considerable evidence for performing a larger trial to investigate whether this combination can be administered for preventing or delaying the onset of T2D in high-risk individuals. TRIAL REGISTRATION: ACTRN12615000559516 , registered on 29 May 2015).