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Taiwanese Journal of Obstetrics &... Jan 2020The efficacy of n-3 fatty acids supplementation on the prevention of pregnancy-induced hypertension or preeclampsia remains unclear. The aim of study was to examine the... (Meta-Analysis)
Meta-Analysis
The efficacy of n-3 fatty acids supplementation on the prevention of pregnancy-induced hypertension or preeclampsia remains unclear. The aim of study was to examine the effect of supplementation with EPA, and/or DHA, and/or ALA during pregnancy on the pregnancy-induced hypertension or preeclampsia. A systematic search was performed on Scopus, PubMed, Web of Science (WoS), Cochrane Library, and Google scholar, which covered the period between 1991 and 2018. The clinical trials with any control groups (i.e. placebo or other supplementation) were selected. The whole process of meta-analysis and data analysis was done using Comprehensive Meta-Analysis (Version 2.0, Biostat). The searched keywords were: "Fatty Acids, Omega-3", "n-3 Polyunsaturated Fatty Acid" "Eicosapentaenoic Acid", "Docosahexaenoic Acids", "n-3 Polyunsaturated Fatty Acid", "n-3 PUFAs", "alpha-Linolenic Acid", "fish oil", "Nuts", "nutrient", or their synonyms "pregnancy induced hypertension" and preeclampsia. In addition, some key journals, according to Scopus report and the references of the original and review articles, were manually searched for possible related studies. The meta-analysis of the 14 comparisons demonstrated that n-3 fatty acids supplementation played a protective role against the risk of preeclampsia (RR, 0.82; 95% CI, 0.70-0.97; p = 0.024; I2 = 19.0%). The analysis of the 10 comparisons revealed that n-3 fatty acid supplements for pregnant women did not mitigate the risk of pregnancy-induced hypertension (RR, 0.98; 95% CI, 0.90-1.07; p = 0.652; I2 = 0%). The n-3 fatty acid supplements are an effective strategy to prevent the incidence of preeclampsia in women with low-risk pregnancies.
Topics: Adult; Dietary Supplements; Fatty Acids, Omega-3; Female; Humans; Hypertension, Pregnancy-Induced; Maternal Nutritional Physiological Phenomena; Pre-Eclampsia; Pregnancy; Prenatal Care; Treatment Outcome
PubMed: 32039806
DOI: 10.1016/j.tjog.2019.11.002 -
BMJ Open May 2019To create a database of long-term randomised controlled trials (RCTs) comparing higher with lower omega-3, omega-6 or total polyunsaturated fatty acid (PUFA), regardless...
OBJECTIVE
To create a database of long-term randomised controlled trials (RCTs) comparing higher with lower omega-3, omega-6 or total polyunsaturated fatty acid (PUFA), regardless of reported outcomes, and to develop methods to assess effects of increasing omega-6, alpha-linolenic acid (ALA), long-chain omega-3 (LCn3) and total PUFA on health outcomes.
DESIGN
Systematic review search, methodology and meta-analyses.
DATA SOURCES
Medline, Embase, CENTRAL, WHO International Clinical Trials Registry Platform, Clinicaltrials.gov and trials in relevant systematic reviews.
ELIGIBILITY CRITERIA
RCTs of ≥24 weeks' duration assessing effects of increasing ALA, LCn3, omega-6 or total PUFAs, regardless of outcomes reported.
DATA SYNTHESIS
Methods included random-effects meta-analyses and sensitivity analyses. Funnel plots were examined, and subgrouping assessed effects of intervention type, replacement, baseline diabetes risk and use of diabetic medications, trial duration and dose. Quality of evidence was assessed using Grading of Recommendations Assessment, Development and Evaluation (GRADE).
RESULTS
Electronic searches generated 37 810 hits, de-duplicated to 19 772 titles and abstracts. We assessed 2155 full-text papers, conference abstracts and trials registry entries independently in duplicate. Included studies were grouped into 363 RCTs comparing higher with lower omega-3, omega-6 and/or total PUFA intake of at least 6 months' duration-the Database.Of these 363 included RCTs, 216 RCTs were included in at least one of our reviews of health outcomes, data extracted and risk of bias assessed in duplicate. Ninety five RCTs were included in the Database but not included in our current reviews. Of these 311 completed trials, 27 altered ALA intake, 221 altered LCn3 intake and 16 trials altered omega-3 intake without specifying whether ALA or LCn3. Forty one trials altered omega-6 and 59 total PUFA.The remaining 52 trials are ongoing though 13 (25%) appear to be outstanding, or constitute missing data.
CONCLUSIONS
This extensive database of trials is available to allow assessment of further health outcomes.
Topics: Chronic Disease; Databases, Factual; Fatty Acids, Omega-3; Fatty Acids, Omega-6; Fatty Acids, Unsaturated; Health Behavior; Humans; Randomized Controlled Trials as Topic
PubMed: 31129605
DOI: 10.1136/bmjopen-2019-029554 -
The Cochrane Database of Systematic... Nov 2018Researchers have suggested that omega-3 polyunsaturated fatty acids from oily fish (long-chain omega-3 (LCn3), including eicosapentaenoic acid (EPA) and docosahexaenoic... (Meta-Analysis)
Meta-Analysis
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. LCn3 doses ranged from 0.5g/d LCn3 to > 5 g/d (16 RCTs gave at least 3g/d LCn3).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 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 ALA 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 with greater effects in trials at low summary risk of bias), and probably reduces risk of 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, except LCn3 reduced triglycerides by ˜15% in a dose-dependant way (high-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 and arrhythmia risk.
Topics: Adult; Arrhythmias, Cardiac; Cardiovascular Diseases; Cause of Death; Coronary Disease; Dietary Supplements; Docosahexaenoic Acids; Eicosapentaenoic Acid; Fatty Acids, Omega-3; Humans; Primary Prevention; Randomized Controlled Trials as Topic; Secondary Prevention; Stroke; Treatment Outcome; alpha-Linolenic Acid
PubMed: 30521670
DOI: 10.1002/14651858.CD003177.pub4 -
Nutrition Reviews Apr 2018Chia seed is a popular dietary supplement, taken mainly for its high content of alpha-linolenic acid, vegetable protein, and dietary fiber, yet information about its... (Meta-Analysis)
Meta-Analysis
CONTEXT
Chia seed is a popular dietary supplement, taken mainly for its high content of alpha-linolenic acid, vegetable protein, and dietary fiber, yet information about its clinical effects is lacking.
OBJECTIVE
This review aims to summarize the clinical evidence regarding the use of chia seed for a wide variety of health conditions.
DATA SOURCES
A number of databases, including PubMed and Embase, were searched systematically.
STUDY SELECTION
Randomized controlled trials that assessed the clinical effects of chia seed consumption in human participants were included. The quality of trials was assessed using the Cochrane Risk of Bias Tool.
DATA EXTRACTION
Data on study design, blinding status, characteristics of participants, chia seed intervention, comparator, clinical assessment, duration of intake, interval of assessment, and study funding status were extracted. Meta-analysis was performed.
RESULTS
Twelve trials were included. Participants included healthy persons, athletes, diabetic patients, and individuals with metabolic syndrome. Pooling of results showed no significant differences except for the following findings of subgroup analysis at higher doses of chia seed: (1) lower postprandial blood glucose level (mean difference [MD] of -33.95 incremental area under the curve [iAUC] [mmol/L × 2 h] [95%CI, -61.85, -6.05] and -51.60 iAUC [mmol/L × 2 h] [95%CI, -79.64, -23.56] at medium doses and high doses, respectively); (2) lower high-density lipoprotein in serum (MD of -0.10 mmol/L [95%CI, -0.20, -0.01]); and (3) lower diastolic blood pressure (MD of -7.14 mmHg [95%CI, -11.08, -3.19]). The quality of all evidence assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach was low or very low. All trials employed only surrogate markers as outcomes.
CONCLUSIONS
Future trials with improved methodological quality, well-described clinical events, and validated surrogate markers as outcomes are needed to support the potential health benefits of chia seed consumption.
SYSTEMATIC REVIEW REGISTRATION
PROSPERO registration no. CRD42015029990.
Topics: Biomarkers; Blood Glucose; Blood Pressure; Dietary Supplements; Humans; Lipoproteins, HDL; Postprandial Period; Salvia; Seeds
PubMed: 29452425
DOI: 10.1093/nutrit/nux071 -
Pharmacological Research Feb 2020Raised plasma lipids are one the most important risk factors for cardiovascular disease. Flaxseed contains considerable amounts of α-linolenic acid, phenolic compounds,... (Meta-Analysis)
Meta-Analysis
Raised plasma lipids are one the most important risk factors for cardiovascular disease. Flaxseed contains considerable amounts of α-linolenic acid, phenolic compounds, and lignans, which each have the capacity to reduce circulating lipid concentrations. This study aimed to systematically review current evidence to identify the potential effects of flaxseed supplementation on blood lipid profiles using a meta-analysis of randomized controlled trials (RCTs). PubMed, Scopus, Web of Science, and Google Scholar databases were searched for publications between January 1900 and May 2019. Weighted mean differences (WMDs) were analyzed using a random-effects model. The Cochrane Collaboration tool was also used to assess the risk of bias of the studies included. Sixty-two RCTs with a total of 3772 participants met the eligibility criteria. Our analysis showed that flaxseed supplementation significantly reduced total cholesterol (TC) (WMD = -5.389 mg/dL; 95% CI: -9.483, -1.295, p = 0.010), triglyceride (TG) (WMD = -9.422 mg/dL; 95% CI: -15.514, -3.330, p = 0.002), and low-density lipoprotein cholesterol (LDL-C) (WMD = -4.206 mg/dl; 95% CI: -7.260, -1.151, p = 0.007) concentrations. However, it had no effects on high-density lipoprotein cholesterol (WMD = 0.047 mg/dl; 95% CI: -0.777, 0.872, p = 0.910). This meta-analysis suggested that flaxseed supplementation improves serum TC, TG, and LDL-C, which could delay the progression of heart disease. Further studies with large-scale and better design are now needed to confirm these results.
Topics: Animals; Dietary Supplements; Dose-Response Relationship, Drug; Flax; Humans; Lipid Metabolism; Randomized Controlled Trials as Topic
PubMed: 31899314
DOI: 10.1016/j.phrs.2019.104622 -
Journal of Psychiatric Research Mar 2019Omega-3 supplements are considered to have anti-inflammatory effects which may be beneficial as inflammation has been linked to ADHD. The aim of this review is to...
The effectiveness of omega-3 supplementation in reducing ADHD associated symptoms in children as measured by the Conners' rating scales: A systematic review of randomized controlled trials.
Omega-3 supplements are considered to have anti-inflammatory effects which may be beneficial as inflammation has been linked to ADHD. The aim of this review is to examine the effectiveness of omega-3 supplementation at reducing ADHD symptoms in children and adolescents. Medline, Cinahl+, PsycINFO, Cochrane and Embase were searched for trials investigating the effects of omega-3 supplementation in children and adolescents with ADHD. The primary outcome measure was a mean difference in Conners' rating scale (CRS) between the intervention and placebo group. Search terms used include ADHD, omega-3, fish oils, eicosapentaenoic acid, docosahexaenoic acids, alpha-linolenic acid and Conners' rating scale. Randomized controlled trials examining the efficacy of omega-3 supplementation in children and adolescents as measured by CRS were included. Studies using a combination of polyunsaturated fatty acids or any other rating scale were excluded. Seven trials were included in this review, totalling 926 participants. We found no evidence of publication bias or heterogeneity between trials. Overall, there was a slightly greater reduction in CRS score in favour of the experiment group. One study found a greater reduction in score in favour of the placebo group. Neither findings were statistically significant. There is little supportive evidence to validate the claim of omega-3 supplementation to reduce the degree of ADHD symptoms experienced by children and adolescents. Both experiment and control groups saw similar reductions in Conners rating scale score.
Topics: Adolescent; Attention Deficit Disorder with Hyperactivity; Child; Fatty Acids, Omega-3; Humans; Outcome Assessment, Health Care; Psychiatric Status Rating Scales; Randomized Controlled Trials as Topic
PubMed: 30594823
DOI: 10.1016/j.jpsychires.2018.12.002