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Mood Disorders and Gluten: It's Not All in Your Mind! A Systematic Review with Meta-Analysis.
Busby, E, Bold, J, Fellows, L, Rostami, K
Nutrients. 2018;10(11)
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Gluten is a protein found in grains such as wheat, barley and rye. For some people, gluten can cause serious health issues such as coeliac disease (CD). A growing body of research suggests that mood symptoms are associated with gluten-related disorders. The objective of this systematic review and meta-analysis was to establish whether a relationship exists between mood and gluten consumption. 13 studies were included in the meta-analysis. A gluten-free diet (GFD) significantly reduced depressive symptoms in 953 participants overall. Subgroup analyses revealed no difference in effect on mood between those with and without diagnosed CD or between those with a genetic predisposition to CD. In patients diagnosed with classical CD, a GFD resulted in a statistically significant reduction in mood symptoms, whereas the effect for silent CD patients was not significant. The authors concluded that gluten elimination may represent an effective treatment strategy for mood disorders in individuals with gluten-related disorders. Future studies should focus on gluten and mood in participants without a gut-related disorder, for example, in a population sample with depression. Finally, the level of support available to help a patient in maintaining a GFD diet over time should be carefully considered when recommending a GFD in practice.
Abstract
Gluten elimination may represent an effective treatment strategy for mood disorders in individuals with gluten-related disorders. However, the directionality of the relationship remains unclear. We performed a systematic review of prospective studies for effects of gluten on mood symptoms in patients with or without gluten-related disorders. Six electronic databases (CINAHL, PsycINFO, Medline, Web of Science, Scopus and Cochrane Library) were searched, from inception to 8 August 2018, for prospective studies published in English. Meta-analyses with random-effects were performed. Three randomised-controlled trials and 10 longitudinal studies comprising 1139 participants fit the inclusion criteria. A gluten-free diet (GFD) significantly improved pooled depressive symptom scores in GFD-treated patients (Standardised Mean Difference (SMD) -0.37, 95% confidence interval (CI) -0.55 to -0.20; p < 0.0001), with no difference in mean scores between patients and healthy controls after one year (SMD 0.01, 95% CI -0.18 to 0.20, p = 0.94). There was a tendency towards worsening symptoms for non-coeliac gluten sensitive patients during a blinded gluten challenge vs. placebo (SMD 0.21, 95% CI -0.58 to 0.15; p = 0.25). Our review supports the association between mood disorders and gluten intake in susceptible individuals. The effects of a GFD on mood in subjects without gluten-related disorders should be considered in future research.
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Cardiometabolic risk factors in vegans; A meta-analysis of observational studies.
Benatar, JR, Stewart, RAH
PloS one. 2018;13(12):e0209086
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Healthy, balanced, plant-based diets have been associated with better health outcomes, however the role of dairy and meat products on heart disease and death due to heart disease is not fully understood. Vegan diets are strictly plant-based and could provide an opportunity to investigate the effect of eliminating animal products on heart disease risk. This meta-analysis of 40 observational studies aimed to evaluate the effect of a vegan diet on heart disease risk factors. The results showed that vegans in most countries had improved heart disease risk factors such as a small waist circumference, lower body mass index (BMI) and balanced blood sugars compared to omnivores, however studies from Taiwan failed to show this trend. It was concluded that a vegan diet in most countries is associated with better health outcomes compared to an omnivorous diet. This study could be use by healthcare practitioners to recommend a vegan diet to those at a higher risk of heart disease.
Abstract
BACKGROUND There is increasing evidence that plant based diets are associated with lower cardiovascular risk. OBJECTIVE To evaluate effects of a vegan compared to an omnivorous diet on cardio-metabolic risk factors. METHODS Meta-analysis of observational studies published between 1960 and June 2018 that reported one or more cardio-metabolic risk factors in vegans and controls eating an omnivorous diet were undertaken. Macro-nutrient intake and cardio-metabolic risk factors were compared by dietary pattern. The Newcastle Ottawa Scale (NOS) was used to assess the quality of each study. The inverse-variance method was used to pool mean differences. Statistical analyses were performed using RevMan software version 5•2 (The Nordic Cochrane Centre, The Cochrane Collaboration, Copenhagen. RESULTS 40 studies with 12 619 vegans and 179 630 omnivores were included. From food frequency questionnaires in 28 studies, vegans compared to omnivores consumed less energy (-11%, 95% confidence interval -14 to -8) and less saturated fat (- 51%, CI -57 to -45). Compared to controls vegans had a lower body mass index (-1.72 kg/m2, CI -2.30 to -1.16), waist circumference (-2.35 cm, CI -3.93 to -0.76), low density lipoprotein cholesterol (-0.49 mmol/L CI -0.62 to -0.36), triglycerides (-0.14 mmol/L, CI -0.24 to -0.05), fasting blood glucose (-0.23 mmol/, CI -0.35 to -0.10), and systolic (-2.56 mmHg, CI -4.66 to -0.45) and diastolic blood pressure (-1.33 mmHg, CI -2.67 to -0.02), p<0.0001 for all. Results were consistent for studies with < and ≥ 50 vegans, and published before and after 2010. However in several large studies from Taiwan a vegan diet was not associated with favourable cardio-metabolic risk factors compared to the control diets. CONCLUSION In most countries a vegan diet is associated with a more favourable cardio- metabolic profile compared to an omnivorous diet.
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Headache Associated with Coeliac Disease: A Systematic Review and Meta-Analysis.
Zis, P, Julian, T, Hadjivassiliou, M
Nutrients. 2018;10(10)
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Coeliac disease (CD) is the best-recognised gluten-related disorder (GRD), and it is characterized by a small bowel enteropathy occurring in genetically susceptible individuals whilst exposed to the protein gliadin. The aim of this study was to systematically review the current literature in order to establish the relationship between headache and CD. This study is a systematic review of 40 articles, studying a total of 42,388 individuals with either headache or GRD. Results show that: - There is an increased prevalence of headache amongst patients with CD. - There is an increased prevalence of CD amongst patients with idiopathic headache. - Headaches associated with CD are mainly migraines. - Gluten-free diet is a very effective treatment for headaches associated with CD. Authors conclude that further studies on the prevalence of gluten sensitivity in patients with idiopathic headache are needed, including further research on the pathogenetic mechanisms.
Abstract
OBJECTIVE The aim of this systematic review was to explore the relationship between coeliac disease (CD) and headache. The objectives were to establish the prevalence of each entity amongst the other, to explore the role of gluten free diet (GFD), and to describe the imaging findings in those affected by headaches associated with CD. METHODOLOGY A systematic computer-based literature search was conducted on the PubMed database. Information regarding study type, population size, the age group included, prevalence of CD amongst those with headache and vice versa, imaging results, the nature of headache, and response to GFD. RESULTS In total, 40 articles published between 1987 and 2017 qualified for inclusion in this review. The mean pooled prevalence of headache amongst those with CD was 26% (95% CI 19.5⁻33.9%) in adult populations and 18.3% (95% CI 10.4⁻30.2%) in paediatric populations. The headaches are most often migraine-like. In children with idiopathic headache, the prevalence of CD is 2.4% (95% CI 1.5⁻3.7%), whereas data for adult populations is presently unavailable. Brain imaging can be normal, although, cerebral calcifications on CT, white matter abnormalities on MRI and deranged regional cerebral blood flow on SPECT can be present. GFD appears to be an effective management for headache in the context of CD, leading to total resolution of headaches in up to 75% of patients. CONCLUSIONS There is an increased prevalence of CD amongst idiopathic headache and vice versa. Therefore, patients with headache of unknown origin should be screened for CD, as such patients may symptomatically benefit from a GFD.
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Body mass index, abdominal fatness, weight gain and the risk of psoriasis: a systematic review and dose-response meta-analysis of prospective studies.
Aune, D, Snekvik, I, Schlesinger, S, Norat, T, Riboli, E, Vatten, LJ
European journal of epidemiology. 2018;33(12):1163-1178
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Psoriasis is an immune-mediated inflammatory skin disease characterised by red, itchy, scaly and flaky skin. Research has shown an association between adiposity and inflammation cytokine release triggered by adipose tissue and increased body mass index and psoriasis. In this meta-analysis, seven prospective studies were included, and the association between BMI, abdominal fat, and psoriasis was examined. According to this meta-analysis, the relative risk of psoriasis increases by 19% for every 5-unit increase in BMI, 24% for a 10 cm increase in waist circumference, 37% for a 0.1-unit increase in waist-to-hip ratio, and 11% for a 5 kg weight gain. The risk of psoriasis was lower for people with a BMI below 20, and it was significantly higher for those with a BMI between 22.5-24. Psoriasis risk was positively associated with waist circumference, waist-to-hip ratio, and weight gain. Psoriasis risk escalates by 2-4 times with an increase in each measure of adiposity. Several potential strategies to reduce the risk of psoriasis are identified in this meta-analysis, including weight loss, dietary factors, and physical activity. To evaluate their effectiveness and develop appropriate strategies, further robust studies are needed. Healthcare professionals can use the results of this study to develop potential therapeutic strategies to reduce the risk of psoriasis by understanding the mechanisms and factors associated with the disease.
Abstract
Greater body mass index (BMI) has been associated with increased risk of psoriasis in case-control and cross-sectional studies, however, the evidence from prospective studies has been limited. We conducted a systematic review and dose-response meta-analysis of different adiposity measures and the risk of psoriasis to provide a more robust summary of the evidence based on data from prospective studies. PubMed and Embase databases were searched for relevant studies up to August 8th 2017. Summary relative risks (RRs) and 95% confidence intervals (CIs) were calculated using a random effects model. The summary relative risk (RR) for a 5 unit increment in BMI was 1.19 (95% CI 1.10-1.28, I2 = 83%, n = 7). The association appeared to be stronger at higher compared to lower levels of BMI, pnonlinearity < 0.0001, and the lowest risk was observed at a BMI around 20. The summary RR was 1.24 (95% CI 1.17-1.31, I2 = 0%, pheterogeneity = 0.72, n = 3) per 10 cm increase in waist circumference, 1.37 (95% CI 1.23-1.53, I2 = 0%, pheterogeneity = 0.93, n = 3) per 0.1 unit increase in waist-to-hip ratio, and 1.11 (95% CI 1.07-1.16, I2 = 47%, pheterogeneity = 0.15, n = 3) per 5 kg of weight gain. Adiposity as measured by BMI, waist circumference, waist-to-hip ratio, and weight gain is associated with increased risk of psoriasis.
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Effect of ω-3 polyunsaturated fatty acid-supplemented parenteral nutrition on inflammatory and immune function in postoperative patients with gastrointestinal malignancy: A meta-analysis of randomized control trials in China.
Zhao, Y, Wang, C
Medicine. 2018;97(16):e0472
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Omega-3 polyunsaturated fatty acids (PUFAs) can have a beneficial effect on inflammation and immune function. This meta-analysis looked at the effectiveness of omega-3 PUFAs on inflammatory and immune function in patients with stomach or colorectal cancers, following surgery. 16 Chinese randomised controlled trials with over 1000 patients carried out between 2000 and 2017 were included in the analysis. The researchers found that the numbers of immune cells in the omega-3 group were significantly higher than those in the control group. The levels of antibodies in people given omega-3 were significantly higher than those in the control group. Inflammatory markers in the omega-3 group were significantly lower. Those given omega-3 were 64% less likely to experience post-surgical infections. The result of this meta-analysis confirmed that supplementing gastrointestinal cancer patients with omega-3 improves post-surgery indicators of immune function, reduces inflammation, and reduces infections related to surgery. The authors recommend that omega-3 should be added to the nutrition formula given to gastrointestinal cancer patients following surgery.
Abstract
BACKGROUND There are no consensus regarding the efficacy of omega-3polyunsaturated fatty acids (PUFAs) on inflammatory and immune function in postoperative patients with gastrointestinal malignancy. METHODS The literatures published randomized control trials (RCT) were searched in PubMed, Embase, Scopus, Cochrane Library, CNKI, Weipu, and Wanfang Databases. The immune efficacy outcomes of ω-3 polyunsaturated fatty acid-supplemented parenteral nutrition in patients with gastrointestinal malignancy were compared. RESULTS Sixteen RCTs involving 1008 patients (506 in the omega-3 group, 502 in the control group) were enrolled into the analysis. The results of meta-analysis: the cell immunity: The proportions of CD3, CD4, CD4/CD8 in the omega-3 group were significantly higher than those in the control group (CD3: WMD = 4.48; 95% CI, 3.34-5.62; P < .00001; I = 0%; CD4: WMD = 5.55; 95% CI, 4.75-6.34; P < .00001; I = 0%; CD4/CD8: WMD = .28; 95% CI, 0.13-0.44; P = .0004; I = 81%). In the humoral immunity: The levels of IgA, IgM and IgG in the omega-3 group were significantly higher than those in the control group (IgA: WMD = 0.31; 95% CI, 0.25-0.37; P < .00001; I = 0%; IgM: WMD = 0.12; 95% CI, 0.06-1.81; P < .00001; I = 0%; IgG: WMD = 1.19; 95% CI, 0.80-1.58; P < .00001; I = 0%). The count of lymphocyte in the omega-3 group was significantly higher than that in the control group (WMD = 0.22; 95% CI, 0.12-0.33; P < .0001; I = 40%). In the postoperative inflammatory cytokine: The levels of interleukin-6, tumor necrosis factor (TNF)-α and C-reactive protein in the omega-3 group were significantly lower than those in the control group (IL-6: WMD = -3.09; 95% CI, -3.91 to 2.27; P < .00001; I = 45%; TNF-α: WMD = -1.65; 95% CI, -2.05 to 1.25; P < .00001; I = 28%; CRP: WMD = -4.28; 95% CI, -5.26 to 3.30; P < .00001; I = 37%). The rate of postoperative infective complications in the omega-3 group was significantly lower than that in the control group (OR = 0.36; 95% CI, 0.20-0.66; P = .0008; I = 0%). CONCLUSION This meta-kanalysis confirmed that early intervention with Omega -3 fatty acid emulsion in gastrointestinal cancer can not only improve the postoperative indicators of immune function, reduce inflammatory reaction, and improve the postoperative curative effect but also improve the immune suppression induced by conventional PN or tumor. Therefore, postoperative patients with gastrointestinal cancer should add omega-3 unsaturated fatty acids in their PN formula. Further high-quality RCTs are needed to verify its efficacy.
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Dairy product consumption and risk of hip fracture: a systematic review and meta-analysis.
Bian, S, Hu, J, Zhang, K, Wang, Y, Yu, M, Ma, J
BMC public health. 2018;18(1):165
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Dairy products contain calcium and Vitamin D, two elements that are known to support bone health. The consumption of dairy products therefore, may affect the risk of bone fracture, however the research remains inconclusive. This meta-analysis examined and quantified the potential association between dairy consumption and the risk of hip fracture. The final analysis included 10 cohort studies and 8 case-control studies. After pooling the data from these studies, the researchers concluded that: • Consumption of yoghurt and cheese was associated with a lower risk of hip fracture • Consumption of total dairy products and cream was not significantly associated with the risk of hip fracture • There was insufficient evidence to deduce an association between milk consumption and the risk of hip fracture. 200g of milk per day may be beneficial however the effects of higher volumes were unclear.
Abstract
BACKGROUND Dairy product consumption may affect the risk of hip fracture, but previous studies have reported inconsistent findings. The primary aim of our meta-analysis was to examine and quantify the potential association of dairy product consumption with risk of hip fracture. METHODS We searched the databases of PubMed and EMBASE for relevant articles from their inception through April 17, 2017. The final analysis included 10 cohort studies and 8 case-control studies. Random-effects models were used to estimate the pooled risk. Subgroup and dose-response analyses were conducted to explore the relationships between the consumption of milk and the risk of hip fracture. RESULTS After pooling the data from the included studies, the summary relative risk (RR) for hip fracture for highest versus lowest consumption were 0.91 (95% CI: 0.74-1.12), 0.75 (95% CI: 0.66-0.86), 0.68 (95% CI: 0.61-0. 77), 1.02 (95% CI: 0.93-1.12) for milk, yogurt, cheese, and total dairy products in cohort studies, respectively. Higher milk consumption [Odds ratio (OR), 0.71, 95% CI: 0.55-0. 91] was associated with lower risk of hip fracture for highest versus lowest consumption in case-control studies. After quantifying the specific dose of milk, the summary RR/OR for an increased milk consumption of 200 g/day was 1.00 (95% CI: 0.94-1.07), and 0.89 (95%CI: 0.64-1.24) with significant heterogeneity for cohort and case-control studies, respectively; There was a nonlinear association between milk consumption and hip fracture risk in cohort, and case-control studies. CONCLUSIONS Our findings indicate that consumption of yogurt and cheese was associated with lower risk of hip fracture in cohort studies. However, the consumption of total dairy products and cream was not significantly associated with the risk of hip fracture. There was insufficient evidence to deduce the association between milk consumption and risk of hip fracture. A lower threshold of 200 g/day milk intake may have beneficial effects, whereas the effects of a higher threshold of milk intake are unclear.
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Effects of caffeine intake on muscle strength and power: a systematic review and meta-analysis.
Grgic, J, Trexler, ET, Lazinica, B, Pedisic, Z
Journal of the International Society of Sports Nutrition. 2018;15:11
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The possible physical performance enhancing (or 'ergogenic) effects of caffeine have been extensively studied since the early 1900s. Recent focus has shifted to its impact on anaerobic physical performance outcomes such as muscular strength, endurance and jumping tasks that require power. Although it has been found to enhance muscle endurance, less is known about its impact on strength and power. This is the first meta-analysis on caffeine and muscle power, and includes 20 studies - ten on muscle strength outcomes and ten on muscle power. The analysis found that caffeine significantly improves muscle strength (SMD = 0.20; 95% confidence interval [CI]: 0.03, 0.36; p = 0.023) but only for upper and not lower body strength. These results were found for men but more robust studies are needed to examine the impact for women (although the limited research suggests there may be a positive impact). This is in contrast to a previous meta-analysis that found no impact of caffeine on muscle strength (Polito, Souza, Casonatto & Farinatti, 2016). It was also found to significantly improve muscle power (SMD = 0.17; 95% CI: 0.00, 0.34; p = 0.047). Although the pooled effect of caffeine on performance outcomes was small to medium, even small improvements can make a big difference competitively. Future research is needed to identify the best dosage and form of caffeine to maximise its performance enhancing effects. Additionally, more robust research is needed to reduce bias, and studies including women. It is important to recognise that individual physical performance changes as a result of caffeine are variable, so these findings must be applied on a case-by-case basis. * Polito MD, Souza DB, Casonatto J, Farinatti P. Acute effect of caffeine consumption on isotonic muscular strength and endurance: a systematic review and meta-analysis. Sci Sports. 2016;31:119–28.
Abstract
BACKGROUND Caffeine is commonly used as an ergogenic aid. Literature about the effects of caffeine ingestion on muscle strength and power is equivocal. The aim of this systematic review and meta-analysis was to summarize results from individual studies on the effects of caffeine intake on muscle strength and power. METHODS A search through eight databases was performed to find studies on the effects of caffeine on: (i) maximal muscle strength measured using 1 repetition maximum tests; and (ii) muscle power assessed by tests of vertical jump. Meta-analyses of standardized mean differences (SMD) between placebo and caffeine trials from individual studies were conducted using the random effects model. RESULTS Ten studies on the strength outcome and ten studies on the power outcome met the inclusion criteria for the meta-analyses. Caffeine ingestion improved both strength (SMD = 0.20; 95% confidence interval [CI]: 0.03, 0.36; p = 0.023) and power (SMD = 0.17; 95% CI: 0.00, 0.34; p = 0.047). A subgroup analysis indicated that caffeine significantly improves upper (SMD = 0.21; 95% CI: 0.02, 0.39; p = 0.026) but not lower body strength (SMD = 0.15; 95% CI: -0.05, 0.34; p = 0.147). CONCLUSION The meta-analyses showed significant ergogenic effects of caffeine ingestion on maximal muscle strength of upper body and muscle power. Future studies should more rigorously control the effectiveness of blinding. Due to the paucity of evidence, additional findings are needed in the female population and using different forms of caffeine, such as gum and gel.
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Nutritional labelling for healthier food or non-alcoholic drink purchasing and consumption.
Crockett, RA, King, SE, Marteau, TM, Prevost, AT, Bignardi, G, Roberts, NW, Stubbs, B, Hollands, GJ, Jebb, SA
The Cochrane database of systematic reviews. 2018;2:CD009315
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Poor quality diets are a threat to health internationally and a challenge to health services. Implementing methods to change people's choices is difficult; even those who start making healthier choices often find it hard to maintain long-term. There is recognition that our environment has a powerful influence over our food choices and altering this may stimulate behavioural change. Nutritional labels provide information about the nutritional content of a food or drink. The type of information provided varies e.g. what nutrients they describe (e.g. macronutrients like fat or energy content) and the form also varies e.g. as a single number, as a proportion of a guideline for daily consumption, or with colours indicative of relative healthiness. Nutritional labelling has been rolled-out in many forms, across many countries but there is currently no consensus as to the best way of applying this information to products to stimulate healthier food choices. This review explored whether nutritional labels persuade consumers to buy alternative types of food and included 28 articles. Findings from these 28 articles suggest that nutritional labelling specially indicating energy content may cause people to opt to buy foods with a lower energy content in restaurants. This result (only based on 3 studies) suggests that nutritional labelling could be rolled-out on menus in restaurants, but high-quality research is required. Higher-quality research is also needed to explore the impact of nutritional labelling in shops and vending machines.
Abstract
BACKGROUND Nutritional labelling is advocated as a means to promote healthier food purchasing and consumption, including lower energy intake. Internationally, many different nutritional labelling schemes have been introduced. There is no consensus on whether such labelling is effective in promoting healthier behaviour. OBJECTIVES To assess the impact of nutritional labelling for food and non-alcoholic drinks on purchasing and consumption of healthier items. Our secondary objective was to explore possible effect moderators of nutritional labelling on purchasing and consumption. SEARCH METHODS We searched 13 electronic databases including CENTRAL, MEDLINE and Embase to 26 April 2017. We also handsearched references and citations and sought unpublished studies through websites and trials registries. SELECTION CRITERIA Eligible studies: were randomised or quasi-randomised controlled trials (RCTs/Q-RCTs), controlled before-and-after studies, or interrupted time series (ITS) studies; compared a labelled product (with information on nutrients or energy) with the same product without a nutritional label; assessed objectively measured purchasing or consumption of foods or non-alcoholic drinks in real-world or laboratory settings. DATA COLLECTION AND ANALYSIS Two authors independently selected studies for inclusion and extracted study data. We applied the Cochrane 'Risk of bias' tool and GRADE to assess the quality of evidence. We pooled studies that evaluated similar interventions and outcomes using a random-effects meta-analysis, and we synthesised data from other studies in a narrative summary. MAIN RESULTS We included 28 studies, comprising 17 RCTs, 5 Q-RCTs and 6 ITS studies. Most (21/28) took place in the USA, and 19 took place in university settings, 14 of which mainly involved university students or staff. Most (20/28) studies assessed the impact of labelling on menus or menu boards, or nutritional labelling placed on, or adjacent to, a range of foods or drinks from which participants could choose. Eight studies provided participants with only one labelled food or drink option (in which labelling was present on a container or packaging, adjacent to the food or on a display board) and measured the amount consumed. The most frequently assessed labelling type was energy (i.e. calorie) information (12/28).Eleven studies assessed the impact of nutritional labelling on purchasing food or drink options in real-world settings, including purchases from vending machines (one cluster-RCT), grocery stores (one ITS), or restaurants, cafeterias or coffee shops (three RCTs, one Q-RCT and five ITS). Findings on vending machines and grocery stores were not interpretable, and were rated as very low quality. A meta-analysis of the three RCTs, all of which assessed energy labelling on menus in restaurants, demonstrated a statistically significant reduction of 47 kcal in energy purchased (MD -46.72 kcal, 95% CI -78.35, -15.10, N = 1877). Assuming an average meal of 600 kcal, energy labelling on menus would reduce energy purchased per meal by 7.8% (95% CI 2.5% to 13.1%). The quality of the evidence for these three studies was rated as low, so our confidence in the effect estimate is limited and may change with further studies. Of the remaining six studies, only two (both ITS studies involving energy labels on menus or menus boards in a coffee shop or cafeteria) were at low risk of bias, and their results support the meta-analysis. The results of the other four studies which were conducted in a restaurant, cafeterias (2 studies) or a coffee shop, were not clearly reported and were at high risk of bias.Seventeen studies assessed the impact of nutritional labels on consumption in artificial settings or scenarios (henceforth referred to as laboratory studies or settings). Of these, eight (all RCTs) assessed the effect of labels on menus or placed on a range of food options. A meta-analysis of these studies did not conclusively demonstrate a reduction in energy consumed during a meal (MD -50 kcal, 95% CI -104.41, 3.88, N = 1705). We rated the quality of the evidence as low, so our confidence in the effect estimate is limited and may change with further studies.Six laboratory studies (four RCTs and two Q-RCTs) assessed the impact of labelling a single food or drink option (such as chocolate, pasta or soft drinks) on energy consumed during a snack or meal. A meta-analysis of these studies did not demonstrate a statistically significant difference in energy (kcal) consumed (SMD 0.05, 95% CI -0.17 to 0.27, N = 732). However, the confidence intervals were wide, suggesting uncertainty in the true effect size. We rated the quality of the evidence as low, so our confidence in the effect estimate is limited and may change with further studies.There was no evidence that nutritional labelling had the unintended harm of increasing energy purchased or consumed. Indirect evidence came from five laboratory studies that involved mislabelling single nutrient content (i.e. placing low energy or low fat labels on high-energy foods) during a snack or meal. A meta-analysis of these studies did not demonstrate a statistically significant increase in energy (kcal) consumed (SMD 0.19, 95% CI -0.14to 0.51, N = 718). The effect was small and the confidence intervals wide, suggesting uncertainty in the true effect size. We rated the quality of the evidence from these studies as very low, providing very little confidence in the effect estimate. AUTHORS' CONCLUSIONS Findings from a small body of low-quality evidence suggest that nutritional labelling comprising energy information on menus may reduce energy purchased in restaurants. The evidence assessing the impact on consumption of energy information on menus or on a range of food options in laboratory settings suggests a similar effect to that observed for purchasing, although the evidence is less definite and also of low quality.Accordingly, and in the absence of observed harms, we tentatively suggest that nutritional labelling on menus in restaurants could be used as part of a wider set of measures to tackle obesity. Additional high-quality research in real-world settings is needed to enable more certain conclusions.Further high-quality research is also needed to address the dearth of evidence from grocery stores and vending machines and to assess potential moderators of the intervention effect, including socioeconomic status.
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Omega-3 fatty acids for the primary and secondary prevention of cardiovascular disease.
Abdelhamid, AS, Brown, TJ, Brainard, JS, Biswas, P, Thorpe, GC, Moore, HJ, Deane, KH, AlAbdulghafoor, FK, Summerbell, CD, Worthington, HV, et al
The Cochrane database of systematic reviews. 2018;7:CD003177
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Dietary intake or supplementation with omega-3 fats from fish and some plant foods such as flaxseed, are commonly believed to reduce the risk of cardiovascular disease. This systematic review of 79 trials, including 112,000 individuals, aimed to assess the impacts of greater omega-3 intake versus lower or no omega-3 intake for heart and circulatory disease. The results of this systematic review showed that increasing EPA and DHA (omega-3 oils from fish) had little or no effect on all cause death or cardiovascular events and probably little or no effect on cardiovascular deaths (evidence mainly from supplement trials). EPA and DHA were found to reduce blood fat levels (triglycerides) and raise HDL (good cholesterol). Eating more ALA (omega-3 fats from walnuts for example) probably makes little or no difference to all-cause or cardiovascular death but probably slightly reduce cardiovascular events.
Abstract
BACKGROUND Researchers have suggested that omega-3 polyunsaturated fatty acids from oily fish (long-chain omega-3 (LCn3), including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)), as well as from plants (alpha-linolenic acid (ALA)) benefit cardiovascular health. Guidelines recommend increasing omega-3-rich foods, and sometimes supplementation, but recent trials have not confirmed this. OBJECTIVES To assess effects of increased intake of fish- and plant-based omega-3 for all-cause mortality, cardiovascular (CVD) events, adiposity and lipids. SEARCH METHODS We searched CENTRAL, MEDLINE and Embase to April 2017, plus ClinicalTrials.gov and World Health Organization International Clinical Trials Registry to September 2016, with no language restrictions. We handsearched systematic review references and bibliographies and contacted authors. SELECTION CRITERIA We included randomised controlled trials (RCTs) that lasted at least 12 months and compared supplementation and/or advice to increase LCn3 or ALA intake versus usual or lower intake. DATA COLLECTION AND ANALYSIS Two review authors independently assessed studies for inclusion, extracted data and assessed validity. We performed separate random-effects meta-analysis for ALA and LCn3 interventions, and assessed dose-response relationships through meta-regression. MAIN RESULTS We included 79 RCTs (112,059 participants) in this review update and found that 25 were at low summary risk of bias. Trials were of 12 to 72 months' duration and included adults at varying cardiovascular risk, mainly in high-income countries. Most studies assessed LCn3 supplementation with capsules, but some used LCn3- or ALA-rich or enriched foods or dietary advice compared to placebo or usual diet.Meta-analysis and sensitivity analyses suggested little or no effect of increasing LCn3 on all-cause mortality (RR 0.98, 95% CI 0.90 to 1.03, 92,653 participants; 8189 deaths in 39 trials, high-quality evidence), cardiovascular mortality (RR 0.95, 95% CI 0.87 to 1.03, 67,772 participants; 4544 CVD deaths in 25 RCTs), cardiovascular events (RR 0.99, 95% CI 0.94 to 1.04, 90,378 participants; 14,737 people experienced events in 38 trials, high-quality evidence), coronary heart disease (CHD) mortality (RR 0.93, 95% CI 0.79 to 1.09, 73,491 participants; 1596 CHD deaths in 21 RCTs), stroke (RR 1.06, 95% CI 0.96 to 1.16, 89,358 participants; 1822 strokes in 28 trials) or arrhythmia (RR 0.97, 95% CI 0.90 to 1.05, 53,796 participants; 3788 people experienced arrhythmia in 28 RCTs). There was a suggestion that LCn3 reduced CHD events (RR 0.93, 95% CI 0.88 to 0.97, 84,301 participants; 5469 people experienced CHD events in 28 RCTs); however, this was not maintained in sensitivity analyses - LCn3 probably makes little or no difference to CHD event risk. All evidence was of moderate GRADE quality, except as noted.Increasing ALA intake probably makes little or no difference to all-cause mortality (RR 1.01, 95% CI 0.84 to 1.20, 19,327 participants; 459 deaths, 5 RCTs),cardiovascular mortality (RR 0.96, 95% CI 0.74 to 1.25, 18,619 participants; 219 cardiovascular deaths, 4 RCTs), and it may make little or no difference to CHD events (RR 1.00, 95% CI 0.80 to 1.22, 19,061 participants, 397 CHD events, 4 RCTs, low-quality evidence). However, increased ALA may slightly reduce risk of cardiovascular events (from 4.8% to 4.7%, RR 0.95, 95% CI 0.83 to 1.07, 19,327 participants; 884 CVD events, 5 RCTs, low-quality evidence), and probably reduces risk of CHD mortality (1.1% to 1.0%, RR 0.95, 95% CI 0.72 to 1.26, 18,353 participants; 193 CHD deaths, 3 RCTs), and arrhythmia (3.3% to 2.6%, RR 0.79, 95% CI 0.57 to 1.10, 4,837 participants; 141 events, 1 RCT). Effects on stroke are unclear.Sensitivity analysis retaining only trials at low summary risk of bias moved effect sizes towards the null (RR 1.0) for all LCn3 primary outcomes except arrhythmias, but for most ALA outcomes, effect sizes moved to suggest protection. LCn3 funnel plots suggested that adding in missing studies/results would move effect sizes towards null for most primary outcomes. There were no dose or duration effects in subgrouping or meta-regression.There was no evidence that increasing LCn3 or ALA altered serious adverse events, adiposity or lipids, although LCn3 slightly reduced triglycerides and increased HDL. ALA probably reduces HDL (high- or moderate-quality evidence). AUTHORS' CONCLUSIONS This is the most extensive systematic assessment of effects of omega-3 fats on cardiovascular health to date. Moderate- and high-quality evidence suggests that increasing EPA and DHA has little or no effect on mortality or cardiovascular health (evidence mainly from supplement trials). Previous suggestions of benefits from EPA and DHA supplements appear to spring from trials with higher risk of bias. Low-quality evidence suggests ALA may slightly reduce CVD event risk, CHD mortality and arrhythmia.
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Pregnancy outcomes in women taking probiotics or prebiotics: a systematic review and meta-analysis.
Jarde, A, Lewis-Mikhael, AM, Moayyedi, P, Stearns, JC, Collins, SM, Beyene, J, McDonald, SD
BMC pregnancy and childbirth. 2018;18(1):14
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It has been suggested that probiotics might help prevent premature birth, but two previous systematic reviews found possible increases in risk. The objective of this meta-analysis was to perform an up-to-date review of the risk of premature birth and other pregnancy outcomes in pregnant women taking probiotics or prebiotics. The authors pooled data from 27 studies, one using prebiotics and the rest probiotics. Taking probiotics or prebiotics during pregnancy did not change the risk of premature birth, or other pregnancy outcomes. The authors concluded that more studies are required to assess the safety and effects of taking probiotics and prebiotics during pregnancy.
Abstract
BACKGROUND Probiotics are living microorganisms that, when administered in adequate amounts, confer a health benefit. It has been speculated that probiotics might help prevent preterm birth, but in two previous systematic reviews possible major increases in this risk have been suggested. Our objective was to perform a systematic review and meta-analysis of the risk of preterm birth and other adverse pregnancy outcomes in pregnant women taking probiotics, prebiotics or synbiotics. METHODS We searched six electronic databases (MEDLINE, EMBASE, CINAHL, Cochrane Central Register of Controlled Trials, Web of Science's Core collection and BIOSIS Preview) up to September 2016 and contacted authors for additional data. We included randomized controlled trials in which women with a singleton pregnancy received a probiotic, prebiotic or synbiotic intervention. Two independent reviewers extracted data using a piloted form and assessed the risk of bias using the Cochrane risk of bias tool. We used random-effects meta-analyses to pool the results. RESULTS We identified 2574 publications, screened 1449 non-duplicate titles and abstracts and read 160 full text articles. The 49 publications that met our inclusion criteria represented 27 studies. No study used synbiotics, one used prebiotics and the rest used probiotics. Being randomized to take probiotics during pregnancy neither increased nor decreased the risk of preterm birth < 34 weeks (RR 1.03, 95% CI 0.29-3.64, I2 0%, 1017 women in 5 studies), preterm birth < 37 weeks (RR 1.08, 95% CI 0.71-1.63, I2 0%, 2484 women in 11 studies), or most of our secondary outcomes, including gestational diabetes mellitus. CONCLUSIONS We found no evidence that taking probiotics or prebiotics during pregnancy either increases or decreases the risk of preterm birth or other infant and maternal adverse pregnancy outcomes. TRIAL REGISTRATION We prospectively published the protocol for this study in the PROSPERO database ( CRD42016048129 ).