Nutritional interventions for preventing and treating pressure ulcers.

BACKGROUND: Pressure ulcers are localized injuries to the skin or the underlying tissue, or both, and are common in older and immobile people, people with diabetes, vascular disease, or malnutrition, as well as those who require intensive or palliative care. People with pressure ulcers often suffer from severe pain and exhibit social avoidance behaviours. The prevention and treatment of pressure ulcers involves strategies to optimize hydration, circulation, and nutrition. Adequate nutrient intake can reduce the risk factor of malnutrition and promote wound healing in existing pressure ulcers. However, it is unclear which nutrients help prevent and treat pressure ulcers. This is an update of an earlier Cochrane Review. OBJECTIVES: To evaluate the benefits and harms of nutritional interventions (special diets, supplements) for preventing and treating pressure ulcers in people with or without existing pressure ulcers compared to standard diet or other nutritional interventions. SEARCH METHODS: We used extensive Cochrane search methods. The latest search was in May 2022. SELECTION CRITERIA: We included randomized controlled trials (RCTs) in people with or without existing pressure ulcers, that compared nutritional interventions aimed at preventing or treating pressure ulcers with standard diet or other types of nutritional interventions. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. Our primary outcome for prevention studies was the proportion of participants who developed new (incident) pressure ulcers. For treatment studies, our primary outcomes were time to complete pressure ulcer healing, number of people with healed pressure ulcers, size and depth of pressure ulcers, and rate of pressure ulcer healing. Secondary outcomes were side effects, costs, health-related quality of life and acceptability. We used GRADE to assess certainty of evidence for each outcome. MAIN RESULTS: We included 33 RCTs with 7920 participants. Data for meta-analysis were available from 6993 participants. Pressure ulcer prevention Eleven studies (with 12 arms) compared six types of nutritional interventions for the prevention of pressure ulcers. Compared to standard diet, energy, protein and micronutrient supplements may result in little to no difference in the proportion of participants developing a pressure ulcer (energy, protein and micronutrient supplements 248 per 1000, standard diet 269 per 1000; RR 0.92, 95% CI 0.71 to 1.19; 3 studies, 1634 participants; low-certainty evidence). Compared to standard diet, protein supplements may result in little to no difference in pressure ulcer incidence (protein 21 per 1000, standard diet 28 per 1000; RR 0.75, 95% CI 0.49 to 1.14; 4 studies, 4264 participants; low-certainty evidence). The evidence is very uncertain about the gastrointestinal side effects of these supplements (protein 109 per 1000, standard diet 155 per 1000; RR 0.70, 95% CI 0.06 to 7.96; 2 studies, 140 participants, very low-certainty evidence). The evidence is very uncertain about the effects of protein, arginine, zinc and antioxidants; L-carnitine, L-leucine, calcium, magnesium and vitamin D; EPA, GLA and antioxidants; disease-specific supplements on pressure ulcer incidence when compared to standard diet (1 study each; very low-certainty evidence for all comparisons). Pressure ulcer treatment Twenty-four studies (with 27 arms) compared 10 types of nutritional interventions or supplements for treatment of pressure ulcers. Compared to standard diet, energy, protein and micronutrient supplements may slightly increase the number of healed pressure ulcers (energy, protein and micronutrients 366 per 1000, standard diet 253 per 1000; RR 1.45, 95% CI 1.14 to 1.85; 3 studies, 577 participants, low-certainty evidence). The evidence is very uncertain about the effect of these supplements on gastrointestinal side effects. Compared to standard diet, the evidence is very uncertain about the effect of protein, arginine, zinc and antioxidant supplements on pressure ulcer healing (pressure ulcer area: mean difference (MD) 2 cm² smaller, 95% CI 4.54 smaller to 0.53 larger; 2 studies, 71 participants, very low-certainty evidence). The evidence on side effects of these supplements is very uncertain. Compared to standard diet, supplements with arginine and micronutrients may not increase the number of healed pressure ulcers, but the evidence suggests a slight reduction in pressure ulcer area (MD 15.8% lower, 95% CI 25.11 lower to 6.48 lower; 2 studies, 231 participants, low-certainty evidence). The evidence is very uncertain about changes in pressure ulcer scores, acceptability, and side effects of these supplements. Compared to placebo, collagen supplements probably improve the mean change in pressure ulcer area (MD 1.81 cm² smaller, 95% CI 3.36 smaller to 0.26 smaller; 1 study, 74 participants, moderate-certainty evidence). The evidence is very uncertain about the effect of these supplements on side effects. The evidence is very uncertain about the effects of vitamin C, different doses of arginine; EPA, GLA (special dietary fatty acids) and antioxidants; protein; a specialized amino acid mixture; ornithine alpha-ketoglutarate and zinc supplements on pressure ulcer healing (1 or 2 studies each; very low-certainty evidence). AUTHORS' CONCLUSIONS: The benefits of nutritional interventions with various compositions for pressure ulcer prevention and treatment are uncertain. There may be little or no difference compared to standard nutrition or placebo. Nutritional supplements may not increase gastrointestinal side effects, but the evidence is very uncertain. Larger studies with similar nutrient compositions would reduce these uncertainties. No study investigated the effects of special diets (e.g. protein-enriched diet, vegetarian diet) on pressure ulcer incidence and healing.

Current Guidelines on Fat Intake in Pregnant and Lactating Women, Infants, Children, and Adolescents: A Scoping Review.

INTRODUCTION: Dietary fat intake in pregnancy, lactation, and childhood determines child growth, neurodevelopment, and long-term health. METHODS: We performed a scoping review of dietary guidelines on fat intake for pregnant and lactating women, infants, children, and adolescents. We systematically searched several databases and websites for relevant documents published in English from 2015 to 2019. RESULTS: We included 14 documents. Of those, eight targeted pregnant and/or lactating women, mainly recommending daily intake of approx. 250 mg/d of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), while one advised supplementing 800 mg/d DHA and 100 mg/d EPA in women of low omega-3 fatty acid status. The number of guidelines for infants was low (n = 3). Recommended intakes of total fat were 30-40% and 20-35% of total energy intake (TEI) for infants and children, respectively. Intakes of saturated fatty acids (SFAs) <10% of TEI and avoidance of trans-fatty acids (TFAs) were recommended across childhood. The methodology applied to develop guidelines and to grade the strength of recommendations was heterogeneous. CONCLUSION: Quantitative recommendations on fat intake during pregnancy focused mainly on PUFA intake, and those targeting infants were limited. Consistent recommendations were provided for total fat, SFA, and TFA intake in childhood; however, strength of recommendation was mostly not reported.

Fat Intake and Fat Quality in Pregnant and Lactating Women, Infants, Children, and Adolescents and Related Health Outcomes: A Scoping Review of Systematic Reviews of Prospective Studies.

INTRODUCTION: Dietary fat intake during pregnancy and childhood is important for health. However, several health aspects are inconclusive. METHODS: We systematically searched Medline, Cochrane Library, and Epistemonikos for systematic reviews (SRs) of randomized controlled trials (RCTs) and/or prospective cohort studies published from January 01, 2015, to December 31, 2019, assessing the association of dietary fat intake (including dietary supplements) during pregnancy and across childhood with pregnancy, perinatal, and child health outcomes. RESULTS: Thirty-one SRs, mainly of RCTs, were included. Omega-3 fatty acids supplementation during pregnancy reduced the risk of early preterm birth, and in some SRs also any preterm birth, increased gestation length and birth weight, but mostly was not associated with other pregnancy/perinatal outcomes. Pre- and postnatal polyunsaturated fatty acids (PUFAs) intake was not consistently associated with growth, neurological, visual and cognitive outcomes, allergic diseases, cardiovascular, and metabolic health in childhood. Reduced saturated fatty acids (SFAs) intake and its replacement with PUFA/monounsaturated fatty acids had favourable effects on blood pressure and blood lipids in children. No apparent effects of total or trans fat on health outcomes across target groups were observed. CONCLUSION: Omega-3 PUFA supplementation during pregnancy and SFA intake reduction in childhood require further consideration in dietary recommendations targeting these populations.

Coconut Oil and Cardiovascular Disease Risk.

PURPOSE OF REVIEW: This narrative review summarizes the current peer-reviewed literature and mechanisms surrounding the cardiovascular health impact of coconut oil. RECENT FINDINGS: No randomized controlled trials (RCTs) and/or prospective cohort studies have investigated the effect or association of coconut oil with cardiovascular disease. Evidence from RCTs indicated that coconut oil seems to have less detrimental effects on total and LDL-cholesterol compared to butter, but not compared to cis-unsaturated vegetable oils, such as safflower, sunflower, or canola oil. The isocaloric replacement (by 1% of energy intake) of carbohydrates with lauric acid (the predominant fatty acid in coconut oil) increased total cholesterol by 0.029 mmol/L (95% CI: 0.014; 0.045), LDL-cholesterol by 0.017 mmol/L (0.003; 0.031), and HDL-cholesterol by 0.019 mmol/L (0.016; 0.023). The current evidence from shorter term RCTs suggests that replacement of coconut oil with cis-unsaturated oils lowers total and LDL-cholesterol, whereas for the association between coconut oil intake and cardiovascular disease, less evidence is available.

Dietary Factors and All-Cause Mortality in Individuals With Type 2 Diabetes: A Systematic Review and Meta-analysis of Prospective Observational Studies.

BACKGROUND: Type 2 diabetes is a major health concern associated with mortality. Diet may influence the progression of diabetes; however, systematic reviews are lacking. PURPOSE: This study systematically summarized the evidence on diet and all-cause mortality in individuals with type 2 diabetes. DATA SOURCES: PubMed and Web of Science were searched until June 2022. STUDY SELECTION: Prospective observational studies investigating dietary factors in association with all-cause mortality in individuals with type 2 diabetes were selected. DATA SYNTHESIS: We identified 107 studies. Moderate certainty of evidence was found for inverse associations of higher intakes of fish (summary risk ratios per serving/week: 0.95; 95% CI 0.92, 0.99; n = 6 studies), whole grain (per 20 g/day: 0.84; 95% CI 0.71, 0.99; n = 2), fiber (per 5 g/day: 0.86; 95% CI 0.81, 0.91; n = 3), and n-3 polyunsaturated fatty acids (per 0.1 g/day: 0.87; 95% CI 0.82, 0.92; n = 2) and mortality. There was low certainty of evidence for inverse associations of vegetable consumption (per 100 g/day: 0.88; 95% CI 0.82, 0.94; n = 2), plant protein (per 10 g/day: 0.91; 95% CI 0.87, 0.96; n = 3), and for positive associations of egg consumption (per 10 g/day: 1.05; 95% CI 1.03, 1.08; n = 7) and cholesterol intake (per 300 mg/day: 1.19; 95% CI 1.13, 1.26; n = 2). For other dietary factors, evidence was uncertain or no association was observed. CONCLUSIONS: Higher intake of fish, whole grain, fiber, and n-3 polyunsaturated fatty acids were inversely associated with all-cause mortality in individuals with type 2 diabetes. There is limited evidence for other dietary factors, and, thus, more research is needed.

Health outcomes associated with micronutrient-fortified complementary foods in infants and young children aged 6-23 months: a systematic review and meta-analysis.

BACKGROUND: Appropriate feeding of infants and young children is essential for healthy growth and the prevention of stunting, wasting, and overweight. We aimed to assess the beneficial versus harmful effects of providing fortified complementary foods to children in the complementary feeding period. METHODS: In this systematic review and meta-analysis, we searched the databases Cochrane Central Register of Controlled Trials, MEDLINE, Embase, Cumulative Index to Nursing and Allied Health Literature, Global Index Medicus, Web of Science, ClinicalTrials.gov, and WHO International Clinical Trials Registry Platform from inception to March 9, 2021. We included randomised controlled trials and controlled clinical trials done in infants and children aged 6-23 months with no identified health problems. Consumption of foods fortified centrally (ie, during industrial processing) with one micronutrient or a combination of vitamins, minerals, or both was compared with the same complementary foods, but without micronutrient fortification. Two review authors independently screened studies for eligibility, extracted data, assessed risk of bias, and rated the certainty of the evidence. The main outcomes were growth (measured by Z scores for weight for age, weight for height or length, and height or length for age, or other growth measures), stunting, wasting, nutrient adequacy or excess, anaemia, haemoglobin concentration, iron status, serum zinc concentration, and serum retinol concentration. We used a random-effects meta-analysis for combining data. This study is registered with PROSPERO, CRD42021245876. FINDINGS: We included 16 studies with 6423 participants, 13 of which were done in malaria-endemic areas. Overall, 12 studies were included in the quantitative syntheses. We identified five further ongoing studies. There was no difference between participants who received fortified complementary foods and those who received non-fortified complementary foods in weight-for-age Z scores (mean difference -0·01, 95% CI -0·07 to 0·06; five trials; 1206 participants; moderate-certainty evidence), weight-for-height or length Z scores (-0·05, -0·19 to 0·10; four trials; 1109 participants; moderate-certainty evidence), and height or length-for-age Z scores (-0·01, -0·21 to 0·20; four trials; 811 participants; low-certainty evidence); stunting and wasting were not assessed in any study as outcomes. Moderate-certainty evidence from six trials with 1209 patients showed that providing fortified complementary foods to children aged 6-23 months reduced the risk of anaemia (risk ratio 0·57, 95% CI 0·39 to 0·82). Those who received fortified complementary foods compared with those who did not had higher haemoglobin concentrations (mean difference 3·44 g/L, 95% CI 1·33 to 5·55; 11 trials; 2175 participants; moderate-certainty evidence) and ferritin concentration (0·43 µg/L on log scale, 0·14 to 0·72; six trials; 903 participants; low-certainty evidence). The intervention led to no effects on serum zinc concentration (-0·13 g/dL, -0·82 to 0·56; two trials; 333 participants; low-certainty evidence) and serum retinol concentration (0·03 µmol/L, -0·02 to 0·08; five trials; 475 participants; moderate-certainty evidence). INTERPRETATION: Fortified complementary foods are effective strategies to prevent anaemia in infants and young children aged 6-23 months in malaria-endemic regions. Effects of complementary food fortification should be further investigated in low-income and middle-income countries, but should also be assessed in high-income countries, and in regions where malaria is not endemic. FUNDING: WHO.

Total Dietary Fat Intake, Fat Quality, and Health Outcomes: A Scoping Review of Systematic Reviews of Prospective Studies.

INTRODUCTION: We conducted a scoping review of systematic reviews (SRs) on dietary fat intake and health outcomes in human adults within the context of a position paper by the "International Union of Nutritional Sciences Task force on Dietary Fat Quality" tasked to summarize the available evidence and provide dietary recommendations. METHODS: We systematically searched several databases for relevant SRs of randomized controlled trials (RCTs) and/or prospective cohort studies published between 2015 and 2019 assessing the association between dietary fat and health outcomes. RESULTS: Fifty-nine SRs were included. The findings from SRs of prospective cohort studies, which frequently compare the highest versus lowest intake categories, found mainly no association of total fat, monounsaturated fatty acid (MUFA), polyunsaturated fatty acid (PUFA), and saturated fatty acid (SFA) with risk of chronic diseases. SRs of RCTs applying substitution analyses indicate that SFA replacement with PUFA and/or MUFA improves blood lipids and glycemic control, with the effect of PUFA being more pronounced. A higher intake of total trans-fatty acid (TFA), but not ruminant TFA, was probably associated with an increased risk of mortality and cardiovascular disease based on existing SRs. CONCLUSION: Overall, the available published evidence deems it reasonable to recommend replacement of SFA with MUFA and PUFA and avoidance of consumption of industrial TFA.

Intake of dietary fats and fatty acids and the incidence of type 2 diabetes: A systematic review and dose-response meta-analysis of prospective observational studies.

BACKGROUND: The role of fat quantity and quality in type 2 diabetes (T2D) prevention is controversial. Thus, this systematic review and meta-analysis aimed to investigate the associations between intake of dietary fat and fatty acids and T2D, and to evaluate the certainty of evidence. METHODS AND FINDINGS: We systematically searched PubMed and Web of Science through 28 October 2019 for prospective observational studies in adults on the associations between intake of dietary fat and fatty acids and T2D incidence. The systematic literature search and data extraction were conducted independently by 2 researchers. We conducted linear and nonlinear random effects dose-response meta-analyses, calculated summary relative risks (SRRs) with their corresponding 95% confidence intervals (95% CIs), and assessed the certainty of evidence. In total, 15,070 publications were identified in the literature search after the removal of duplicates. Out of the 180 articles screened in full text, 23 studies (19 cohorts) met our inclusion criteria, with 11 studies (6 cohorts) conducted in the US, 7 studies (7 cohorts) in Europe, 4 studies (5 cohorts) in Asia, and 1 study (1 cohort) in Australia. We mainly observed no or weak linear associations between dietary fats and fatty acids and T2D incidence. In nonlinear dose-response meta-analyses, the protective association for vegetable fat and T2D was steeper at lower levels up to 13 g/d (SRR [95% CI]: 0.81 [0.76; 0.88], pnonlinearity = 0.012, n = 5 studies) than at higher levels. Saturated fatty acids showed an apparent protective association above intakes around 17 g/d with T2D (SRR [95% CI]: 0.95 [0.90; 1.00], pnonlinearity = 0.028, n = 11). There was a nonsignificant association of a decrease in T2D incidence for polyunsaturated fatty acid intakes up to 5 g/d (SRR [95% CI]: 0.96 [0.91; 1.01], pnonlinearity = 0.023, n = 8), and for alpha-linolenic acid consumption up to 560 mg/d (SRR [95% CI]: 0.95 [0.90; 1.00], pnonlinearity = 0.014, n = 11), after which the curve rose slightly, remaining close to no association. The association for long-chain omega-3 fatty acids and T2D was approximately linear for intakes up to 270 mg/d (SRR [95% CI]: 1.10 [1.06; 1.15], pnonlinearity < 0.001, n = 16), with a flattening curve thereafter. Certainty of evidence was very low to moderate. Limitations of the study are the high unexplained inconsistency between studies, the measurement of intake of dietary fats and fatty acids via self-report on a food group level, which is likely to lead to measurement errors, and the possible influence of unmeasured confounders on the findings. CONCLUSIONS: There was no association between total fat intake and the incidence of T2D. However, for specific fats and fatty acids, dose-response curves provided insights for significant associations with T2D. In particular, a high intake of vegetable fat was inversely associated with T2D incidence. Thus, a diet including vegetable fat rather than animal fat might be beneficial regarding T2D prevention.

Comparative effect of nutraceuticals on lipid profile: a protocol for systematic review and network meta-analysis.

INTRODUCTION: According to the common definition, nutraceuticals are components found in food that can act as therapeutic substances. Recently, the International Lipid Expert Panel published two position papers covering the topic of lipid-lowering nutraceuticals and their potential use as a complementary treatment in addition to statins or as an alternative treatment in statin-intolerant patients. The aim of this study was to compare the effect of different nutraceuticals on lipid profiles in a systematic review with pairwise and network meta-analyses. METHODS AND ANALYSIS: Three databases, including PubMed, Embase and the Cochrane Central Register of Controlled Trials, will be searched without time or publication language restrictions. The estimated end date for the searches will be 29 March 2020. Each stage of the review, including the study section, data extraction, and risk of bias and quality of evidence assessments, will be performed in duplicate. Randomised controlled trials meeting the following criteria will be eligible for inclusion: (1) participants aged ≥18 years, (2) intervention with a selected nutraceutical (artichoke, berberine, bergamot, soluble fibres, green tea, garlic, lupin, plant sterols and stanols, red yeast rice, soybean, spirulina or a combination of the aforementioned nutraceuticals), (3) administration of the treatment in the form of capsules, pills, powders, solutions, tablets or enriched food items, (4) comparison with another nutraceutical or placebo, (5) intervention period ≥3 weeks and (6) lipid profile (low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, total cholesterol, triglycerides) as an outcome. Random-effect pairwise and network meta-analyses will be used to summarise the relative effect of each nutraceutical in comparison to the effect of every other nutraceutical. Subgroup analyses will be stratified by age, sex, ethnicity, sample size, length of trial follow-up, baseline cholesterol level and presence of other comorbidities. ETHICS AND DISSEMINATION: This review will summarise findings from primary studies, and therefore no ethics approval is required. The results will be presented at conferences as well as published in a peer-reviewed journal. PROSPERO REGISTRATION NUMBER: CRD42019132877.

Potatoes and risk of chronic disease: a systematic review and dose-response meta-analysis.

PURPOSE: We aimed to synthesize the evidence on the relation between different types of potato consumption with risk of all-cause mortality, coronary heart disease (CHD), stroke, type 2 diabetes (T2D), colorectal cancer (CRC), and hypertension. METHODS: Systematic searches until May 2018 were conducted in PubMed, Scopus, and Web of Science. Random effects meta-analyses comparing extreme categories, linear and non-linear dose-response analyses were conducted. RESULTS: Twenty-eight reports were identified. Only total potato consumption was available for some endpoints which showed no associations with all-cause mortality (RR: 0.88, 95% CI 0.69-1.12), CHD (RR: 1.03, 95% CI 0.96-1.09), stroke (RR: 0.98, 95% CI 0.93-1.03), and CRC (RR: 1.05, 95% CI 0.92-1.20) per one daily/serving (150 g/day) increase. Consumption of one daily serving of boiled/baked/mashed-potatoes was not associated with risk of hypertension (RR: 1.08, 95% CI 0.96-1.21), but slightly with the risk of T2D (RR: 1.09, 95% 1.01-1.18). Positive associations for the risk of T2D (RR: 1.66, 95% CI 1.43-1.94) and hypertension (RR: 1.37, 95% CI 1.15-1.63) were observed for each 150 g/day increase in French-fries consumption. The quality of evidence was rated mostly low (moderate quality of evidence for the risk-associations of French-fries). CONCLUSION: Total potato consumption is not related to risk for many chronic diseases but could pose a small increase in risk for T2D if consumed boiled. A clear risk relation was found between French-fries consumption and risk of T2D and hypertension. For several outcomes, the impact of different preparation procedures could not be assessed.

Dietary Supplements and Risk of Cause-Specific Death, Cardiovascular Disease, and Cancer: A Systematic Review and Meta-Analysis of Primary Prevention Trials.

Our aim was to assess the efficacy of dietary supplements in the primary prevention of cause-specific death, cardiovascular disease (CVD), and cancer by using meta-analytical approaches. Electronic and hand searches were performed until August 2016. Inclusion criteria were as follows: 1) minimum intervention period of 12 mo; 2) primary prevention trials; 3) mean age ≥18 y; 4) interventions included vitamins, fatty acids, minerals, supplements containing combinations of vitamins and minerals, protein, fiber, prebiotics, and probiotics; and 5) primary outcome of all-cause mortality and secondary outcomes of mortality or incidence from CVD or cancer. Pooled effects across studies were estimated by using random-effects meta-analysis. Overall, 49 trials (69 reports) including 287,304 participants met the inclusion criteria. Thirty-two trials were judged as low risk-, 15 trials as moderate risk-, and 2 trials as high risk-of-bias studies. Supplements containing vitamin E (RR: 0.88; 95% CI: 0.80, 0.96) significantly reduced cardiovascular mortality risk, whereas supplements with folic acid reduced the risk of CVD (RR: 0.81; 95% CI: 0.70, 0.94). Vitamins D, C, and K; selenium; zinc; magnesium; and eicosapentaenoic acid showed no significant risk reduction for any of the outcomes. On the contrary, vitamin A was linked to an increased cancer risk (RR: 1.16; 95% CI: 1.00, 1.35). Supplements with ß-carotene showed no significant effect; however, in the subgroup with ß-carotene given singly, an increased risk of all-cause mortality by 6% (RR: 1.06; 95% CI: 1.02, 1.10) was observed. Taken together, we found insufficient evidence to support the use of dietary supplements in the primary prevention of cause-specific death, incidence of CVD, and incidence of cancer. The application of some supplements generated small beneficial effects; however, the heterogeneous types and doses of supplements limit the generalizability to the overall population.

An Umbrella Review of Nuts Intake and Risk of Cardiovascular Disease.

BACKGROUND: Nuts have been an indispensable component of the human diet for hundreds because of their unique nutrient composition and are thought to play a beneficial part in the prevention of cardiovascular diseases. OBJECTIVE: To evaluate the extent, validity and presence of evidence for studies investigating the impact of nuts intake on biomarkers of cardiovascular disease and cardiovascular events, we performed an umbrella review of all published meta-analyses synthesizing data from both observational studies and randomized controlled trials. METHOD: PubMed (between 1966 and April 2016) was searched for systematic reviews and meta-analyses. Methodological quality was assessed by applying the AMSTAR score (0-11 points), and the meta-evidence by applying NutriGrade, our recently developed scoring system (0-10 points). RESULTS: In total, 14 meta-analyses were included in the umbrella review. Only 4 out of 14 reported an AMSTAR score ≥8 (high methodological quality), whereas NutriGrade meta-evidence score varied between 2 (very low meta-evidence) and 7.9 (moderate meta-evidence). There is consistent evidence from intervention trials, reporting significant reductions for total cholesterol, and from observational studies that higher intakes of nuts were associated with reduced risk of cardiovascular disease and hypertension. On the other side no effect could be observed for stroke, HDL-cholesterol, and blood pressure in the normal range. CONCLUSION: In summary, the present umbrella review showed that nuts intake was associated with reduced risk of cardiovascular disease and hypertension, and lower levels of total cholesterol. The observed evidence is limited by the moderate methodological quality and very low to moderate quality of evidence.

A systematic review and meta-analysis of carbohydrate benefits associated with randomized controlled competition-based performance trials.

BACKGROUND: Carbohydrate supplements are widely used by athletes as an ergogenic aid before and during sports events. The present systematic review and meta-analysis aimed at synthesizing all available data from randomized controlled trials performed under real-life conditions. METHODS: MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials were searched systematically up to February 2015. Study groups were categorized according to test mode and type of performance measurement. Subgroup analyses were done with reference to exercise duration and range of carbohydrate concentration. Random effects and fixed effect meta-analyses were performed using the Software package by the Cochrane Collaboration Review Manager 5.3. RESULTS: Twenty-four randomized controlled trials met the objectives and were included in the present systematic review, 16 of which provided data for meta-analyses. Carbohydrate supplementations were associated with a significantly shorter exercise time in groups performing submaximal exercise followed by a time trial [mean difference -0.9 min (95 % confidence interval -1.7, -0.2), p = 0.02] as compared to controls. Subgroup analysis showed that improvements were specific for studies administering a concentration of carbohydrates between 6 and 8 % [mean difference -1.0 min (95 % confidence interval -1.9, -0.0), p = 0.04]. Concerning groups with submaximal exercise followed by a time trial measuring power accomplished within a fixed time or distance, mean power output was significantly higher following carbohydrate load (mean difference 20.2 W (95 % confidence interval 9.0, 31.5), p = 0.0004]. Likewise, mean power output was significantly increased following carbohydrate intervention in groups with time trial measuring power within a fixed time or distance (mean difference 8.1 W (95 % confidence interval 0.5, 15.7) p = 0.04]. CONCLUSION: Due to the limitations of this systematic review, results can only be applied to a subset of athletes (trained male cyclists). For those, we could observe a potential ergogenic benefit of carbohydrate supplementation especially in a concentration range between 6 and 8 % when exercising longer than 90 min.

An umbrella review of garlic intake and risk of cardiovascular disease.

PURPOSE: To gain further insight into the strength of evidence and extent of possible biases in the scope of studies investigating the impact of garlic and garlic supplement intake on biomarkers of cardiovascular disease, we performed an umbrella review of all published meta-analyses synthesizing data from both observational studies and randomized controlled trials. METHODS: Electronic database PubMed (between 1966 and June 2015) was searched for systematic reviews and meta-analyses using following search terms: ("garlic" OR "allium sativum" OR "allicin" OR "organosulfur") AND ("cardiovascular" OR "coronary" OR "cholesterol" OR "triglyceride" OR "atherosclerosis" OR "blood pressure" OR "hypertension" OR "blood glucose") AND ("systematic review" OR "meta-analysis"), with no restriction to calendar data and language. Hand-search of reference lists and relevant clinical guidelines was performed as well. RESULTS: Nine systematic reviews investigated the effects of garlic on lipid parameters and eight systematic reviews analyzed the effects on blood pressure parameters were identified. Eight of nine meta-analyses synthesizing the effect of garlic on blood lipids reported significantly decreased total cholesterol levels. Inconsistent results could be detected for HDL-cholestrol, LDL-cholesterol, and triacylglycerols. The effect of garlic on systolic blood pressure showed consistent results across publications with 7 out of 8 meta-analyses demonstrating a substantial decrease in systolic blood pressure. Similar results could be reported regarding the effect of garlic on diastolic blood pressure, i.e. 6 out of 8 meta-analyses detected significant reductions in diastolic blood pressure levels following interventions with garlic. CONCLUSION: According to the data summarized in the present umbrella review, garlic preparations as well as garlic exerted some positive effects on indicators and biomarkers of cardiovascular disease, typically without causing any serious side effects. However, with regard to the substantial heterogeneities between the different trials enrolled in the various meta-analyses of this review, a conservative interpretation of the outcome seems to be appropriate.

Dietary supplements and risk of cause-specific death, cardiovascular disease, and cancer: a protocol for a systematic review and network meta-analysis of primary prevention trials.

BACKGROUND: In the Western world, dietary supplements are commonly used to prevent chronic diseases, mainly cardiovascular disease and cancer. However, there is inconsistent evidence on which dietary supplements actually lower risk of chronic disease, and some may even increase risk. We aim to evaluate the comparative safety and/or effectiveness of dietary supplements for the prevention of mortality (all-cause, cardiovascular, and cancer) and cardiovascular and cancer incidence in primary prevention trials. METHODS/DESIGN: We will search PubMed, EMBASE, Cochrane Database of Systematic Reviews, the Database of Abstracts of Reviews of Effects, the Cochrane Central Register of Controlled Trials, clinical trials.gov, and the World Health Organization International Trial Registry Platform. Randomized controlled trials will be included if they meet the following criteria: (1) minimum intervention period of 12 months; (2) primary prevention of chronic disease (is concerned with preventing the onset of diseases and conditions); (3) minimum mean age ≥18 years (maximum mean age 70 years); (4) intervention(s) include vitamins (beta-carotene, vitamin A, B vitamins, Vitamin C, Vitamin D, Vitamin E, and multivitamin supplements); fatty acids (omega-3 fatty acids, omega-6 fatty acids, monounsaturated fat); minerals (magnesium, calcium, selenium, potassium, iron, zinc, copper, iodine; multiminerals); supplements containing combinations of both vitamins and minerals; protein (amino acids); fiber; prebiotics; probiotics; synbiotics; (5) supplements are orally administered as liquids, pills, capsules, tablets, drops, ampoules, or powder; (6) report results on all-cause mortality (primary outcome) and/or mortality from cardiovascular disease or cancer, cardiovascular and/or cancer incidence (secondary outcomes). Pooled effects across studies will be calculated using Bayesian random effects network meta-analysis. Sensitivity analysis will be performed for trials lasting ≥5 years, trials with low risk of bias, trials in elderly people (≥65 years), ethnicity, geographical region, and trials in men and women. The results of the corresponding fixed effects models will also be compared in sensitivity analyses. DISCUSSION: This is a presentation of the study protocol only. Results and conclusions are pending completion of this study. Our systematic review will be of great value to consumers of supplements, healthcare providers, and policy-makers, regarding the use of dietary supplements. PROSPERO: CRD42014014801 .

Monounsaturated fatty acids, olive oil and health status: a systematic review and meta-analysis of cohort studies.

BACKGROUND: The aim of the present meta-analysis of cohort studies was to focus on monounsaturated fat (MUFA) and cardiovascular disease, cardiovascular mortality as well as all-cause mortality, and to distinguish between the different dietary sources of MUFA. METHODS: Literature search was performed using the electronic databases PUBMED, and EMBASE until June 2nd, 2014. Study specific risk ratios and hazard ratios were pooled using a inverse variance random effect model. RESULTS: Thirty-two cohort studies (42 reports) including 841,211 subjects met the objectives and were included. The comparison of the top versus bottom third of the distribution of a combination of MUFA (of both plant and animal origin), olive oil, oleic acid, and MUFA:SFA ratio in each study resulted in a significant risk reduction for: all-cause mortality (RR: 0.89, 95% CI 0.83, 0.96, p = 0.001; I2 = 64%), cardiovascular mortality (RR: 0.88, 95% CI 0.80, 0.96, p = 0.004; I2 = 50%), cardiovascular events (RR: 0.91, 95% CI 0.86, 0.96, p = 0.001; I2 = 58%), and stroke (RR: 0.83, 95% CI 0.71, 0.97, p = 0.02; I2 = 70%). Following subgroup analyses, significant associations could only be found between higher intakes of olive oil and reduced risk of all-cause mortality, cardiovascular events, and stroke, respectively. The MUFA subgroup analyses did not reveal any significant risk reduction. CONCLUSION: The results indicate an overall risk reduction of all-cause mortality (11%), cardiovascular mortality (12%), cardiovascular events (9%), and stroke (17%) when comparing the top versus bottom third of MUFA, olive oil, oleic acid, and MUFA:SFA ratio. MUFA of mixed animal and vegetable sources per se did not yield any significant effects on these outcome parameters. However, only olive oil seems to be associated with reduced risk. Further research is necessary to evaluate specific sources of MUFA (i.e. plant vs. animal) and cardiovascular risk.