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Critical Reviews in Food Science and... 2021To investigate the effect of ALA intake on blood lipid profiles, including triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C),... (Meta-Analysis)
Meta-Analysis
To investigate the effect of ALA intake on blood lipid profiles, including triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), very-low-density lipoprotein (VLDL-C) and ratio of TC to HDL-C. We systematically searched randomized controlled trials of ALA intervention on PubMed, Embase, Cochrane library and related references up to March 2018. The final values were calculated as weighted mean difference (WMD) by using a random effects model. Subgroup analysis and meta-regression were used to explore the source of heterogeneity. Generalized least square was performed for dose-response analysis. Forty-seven studies with 1305 individuals in the ALA arm and 1325 individuals in the control arm were identified. Compared with control group, dietary intake of ALA significantly reduced the concentrations of TG (WMD -0.101 mmol/L; 95% CI: -0.158 to -0.044 mmol/L; 0.001), TC (WMD -0.140 mmol/L; 95% CI: -0.224 to -0.056 mmol/L; 0.001), LDL-C (WMD -0.131 mmol/L; 95% CI: -0.191 to -0.071 mmol/L; 0.001), VLDL-C (WMD -0.121 mmol/L; 95% CI: -0.170 to -0.073 mmol/L; 0.001), TC/HDL-C ratio (WMD -0.165 mmol/L; 95% CI: -0.317 to -0.013 mmol/L; 0.033) and LDL-C/HDL-C ratio (WMD -0.158 mmol/L; 95% CI: -0.291 to -0.025 mmol/L; 0.02). There is no effect of ALA intake on HDL-C (WMD 0.008 mmol/L; 95% CI: -0.018 to 0.034 mmol/L; 0.541). Dose-response analysis indicated that 1 g per day increment of ALA was associated with a 0.0016 mmol/L, 0.0071 mmol/L, 0.0015 and 0.0061 mmol/L reduction in TG (95% CI: -0.0029 to -0.0002 mmol/L), TC (95% CI: -0.0085 to -0.0058 mmol/L), HDL-C (95% CI: -0.0020 to -0.0011 mmol/L) and LDL-C (95% CI: -0.0073 to -0.0049 mmol/L) levels, respectively. The effects of ALA intake on TG, TC and LDL-C concentrations were more obvious among Asian participants, and also more obvious on patients with hyperlipidemia or hyperglycemia compared to healthy individuals. Dietary ALA intervention improves blood lipid profiles by decreasing levels of TG, TC, LDL and VLDL-C. Our findings add to the evidence that increasing ALA intake could potentially prevent risk of cardiovascular diseases.
Topics: Cholesterol, HDL; Cholesterol, LDL; Humans; Lipids; Randomized Controlled Trials as Topic; Triglycerides; alpha-Linolenic Acid
PubMed: 32643951
DOI: 10.1080/10408398.2020.1790496 -
The Cochrane Database of Systematic... Jul 2018Omega-6 fats are polyunsaturated fats vital for many physiological functions, but their effect on cardiovascular disease (CVD) risk is debated. (Review)
Review
BACKGROUND
Omega-6 fats are polyunsaturated fats vital for many physiological functions, but their effect on cardiovascular disease (CVD) risk is debated.
OBJECTIVES
To assess effects of increasing omega-6 fats (linoleic acid (LA), gamma-linolenic acid (GLA), dihomo-gamma-linolenic acid (DGLA) and arachidonic acid (AA)) on CVD and all-cause mortality.
SEARCH METHODS
We searched CENTRAL, MEDLINE and Embase to May 2017 and clinicaltrials.gov and the World Health Organization International Clinical Trials Registry Platform to September 2016, without language restrictions. We checked trials included in relevant systematic reviews.
SELECTION CRITERIA
We included randomised controlled trials (RCTs) comparing higher versus lower omega-6 fat intake in adults with or without CVD, assessing effects over at least 12 months. We included full texts, abstracts, trials registry entries and unpublished studies. Outcomes were all-cause mortality, CVD mortality, CVD events, risk factors (blood lipids, adiposity, blood pressure), and potential adverse events. We excluded trials where we could not separate omega-6 fat effects from those of other dietary, lifestyle or medication interventions.
DATA COLLECTION AND ANALYSIS
Two authors independently screened titles/abstracts, assessed trials for inclusion, extracted data, and assessed risk of bias of included trials. We wrote to authors of included studies. Meta-analyses used random-effects analysis, while sensitivity analyses used fixed-effects and limited analyses to trials at low summary risk of bias. We assessed GRADE quality of evidence for 'Summary of findings' tables.
MAIN RESULTS
We included 19 RCTs in 6461 participants who were followed for one to eight years. Seven trials assessed the effects of supplemental GLA and 12 of LA, none DGLA or AA; the omega-6 fats usually displaced dietary saturated or monounsaturated fats. We assessed three RCTs as being at low summary risk of bias.Primary outcomes: we found low-quality evidence that increased intake of omega-6 fats may make little or no difference to all-cause mortality (risk ratio (RR) 1.00, 95% confidence interval (CI) 0.88 to 1.12, 740 deaths, 4506 randomised, 10 trials) or CVD events (RR 0.97, 95% CI 0.81 to 1.15, 1404 people experienced events of 4962 randomised, 7 trials). We are uncertain whether increasing omega-6 fats affects CVD mortality (RR 1.09, 95% CI 0.76 to 1.55, 472 deaths, 4019 randomised, 7 trials), coronary heart disease events (RR 0.88, 95% CI 0.66 to 1.17, 1059 people with events of 3997 randomised, 7 trials), major adverse cardiac and cerebrovascular events (RR 0.84, 95% CI 0.59 to 1.20, 817 events, 2879 participants, 2 trials) or stroke (RR 1.36, 95% CI 0.45 to 4.11, 54 events, 3730 participants, 4 trials), as we assessed the evidence as being of very low quality. We found no evidence of dose-response or duration effects for any primary outcome, but there was a suggestion of greater protection in participants with lower baseline omega-6 intake across outcomes.Additional key outcomes: we found increased intake of omega-6 fats may reduce myocardial infarction (MI) risk (RR 0.88, 95% CI 0.76 to 1.02, 609 events, 4606 participants, 7 trials, low-quality evidence). High-quality evidence suggests increasing omega-6 fats reduces total serum cholesterol a little in the long term (mean difference (MD) -0.33 mmol/L, 95% CI -0.50 to -0.16, I = 81%; heterogeneity partially explained by dose, 4280 participants, 10 trials). Increasing omega-6 fats probably has little or no effect on adiposity (body mass index (BMI) MD -0.20 kg/m, 95% CI -0.56 to 0.16, 371 participants, 1 trial, moderate-quality evidence). It may make little or no difference to serum triglycerides (MD -0.01 mmol/L, 95% CI -0.23 to 0.21, 834 participants, 5 trials), HDL (MD -0.01 mmol/L, 95% CI -0.03 to 0.02, 1995 participants, 4 trials) or low-density lipoprotein (MD -0.04 mmol/L, 95% CI -0.21 to 0.14, 244 participants, 2 trials, low-quality evidence).
AUTHORS' CONCLUSIONS
This is the most extensive systematic assessment of effects of omega-6 fats on cardiovascular health, mortality, lipids and adiposity to date, using previously unpublished data. We found no evidence that increasing omega-6 fats reduces cardiovascular outcomes other than MI, where 53 people may need to increase omega-6 fat intake to prevent 1 person from experiencing MI. Although benefits of omega-6 fats remain to be proven, increasing omega-6 fats may be of benefit in people at high risk of MI. Increased omega-6 fats reduce serum total cholesterol but not other blood fat fractions or adiposity.
Topics: Adult; Aged; Blood Pressure; Cardiovascular Diseases; Cerebrovascular Disorders; Cholesterol; Cholesterol, HDL; Cholesterol, LDL; Fatty Acids, Omega-6; Female; Humans; Male; Middle Aged; Myocardial Infarction; Primary Prevention; Randomized Controlled Trials as Topic; Secondary Prevention; Triglycerides
PubMed: 30019765
DOI: 10.1002/14651858.CD011094.pub3 -
The Journal of Nutrition Apr 2015High blood pressure is a major health burden positively associated with the risk of cardiovascular disease and other chronic diseases. Flaxseed is a rich dietary source... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
High blood pressure is a major health burden positively associated with the risk of cardiovascular disease and other chronic diseases. Flaxseed is a rich dietary source of α-linolenic acid, lignans, and fiber, with a number of positive health benefits on blood pressure.
OBJECTIVE
The purpose of this study was to clarify the effect of flaxseed consumption on blood pressure. Further, the influence of baseline blood pressure, type of flaxseed supplementation, and duration of flaxseed supplementation on blood pressure was explored.
METHOD
PubMed (MEDLINE), Cumulative Index to Nursing and Allied Health Literature, and Cochrane Library (Central) were searched through July 2014 for studies in which humans supplemented their habitual diet with flaxseed or its extracts (i.e., oil, lignans, fiber) for ≥2 wk.
RESULTS
A total of 11 studies (14 trials) were included in the analysis. Random-effects meta-analyses were conducted for the mean difference in blood pressure. Results indicated that flaxseed supplementation reduced systolic blood pressure (-1.77 mm Hg; 95% CI: -3.45, -0.09 mm Hg; P = 0.04) and diastolic blood pressure (-1.58 mm Hg; 95% CI: -2.64, -0.52 mm Hg; P = 0.003). These results were not influenced by categorization of participants into higher baseline blood pressure (≥130 mm Hg). An improvement in diastolic blood pressure was observed in subgroup analysis for consuming whole flaxseed (-1.93 mm Hg; 95% CI: -3.65, -0.21 mm Hg; P < 0.05) and duration of consumption ≥12 wk (-2.17 mm Hg; 95% CI: -3.44, -0.89 mm Hg; P < 0.05).
CONCLUSION
The present meta-analysis suggests that consumption of flaxseed may lower blood pressure slightly. The beneficial potential of flaxseed to reduce blood pressure (especially diastolic blood pressure) may be greater when it is consumed as a whole seed and for a duration of >12 wk.
Topics: Blood Pressure; Databases, Factual; Diet; Flax; Humans; Hypertension; Phytotherapy; Plant Preparations; Randomized Controlled Trials as Topic; Seeds; Sensitivity and Specificity
PubMed: 25740909
DOI: 10.3945/jn.114.205302 -
Clinical Nutrition (Edinburgh, Scotland) Jun 2024The aim of this network meta-analysis (NMA) was to investigate the effects of different dietary supplements on the mortality and clinical status of adults with sepsis. (Meta-Analysis)
Meta-Analysis
AIM
The aim of this network meta-analysis (NMA) was to investigate the effects of different dietary supplements on the mortality and clinical status of adults with sepsis.
METHODS
We searched PubMed, EMBASE, and the Cochrane Library Central Register of Controlled Trials until February 2023. The inclusion criteria were: 1) randomized controlled trials (RCT)s; 2) adults suffering sepsis or septic shock; 3) evaluation of short- or long-mortality; and 4) publications between 1994 and 2023. The general information of studies and details of interventions were extracted. The primary outcome was short-term mortality (<90 days), and the secondary outcomes were long-term mortality (≥90 days), length of ICU and hospital stays, and duration of mechanical ventilation (MV). The risk of bias of RCTs was assessed using the Cochrane risk of bias tool 2 (ROB2). A random effect NMA was performed to rank the effect of each intervention using a frequentist approach.
RESULTS
Finally, 56 RCTs with 5957 participants met the criteria. Approximately, one-third of RCTs were low risk of bias. NMA analysis revealed that there was no treatment more effective in short- or long-term mortality than control or other interventions, except for magnesium (RR: 0.33, 95% CI: 0.14, 0.79; GRADE = low) and vitamin C (RR: 0.81, 95% CI: 0.67, 0.99; low certainty evidence), which had beneficial effects on short-term mortality. Moreover, eicosapentaenoic acid, gamma-linolenic acid, and antioxidants (EPA + GLA + AOs) combination was the most effective, and magnesium, vitamin D and vitamin C were the other effective approaches in terms of duration of MV, and ICU length of stay. There was no beneficial dietary supplement for hospital stay in these patients.
CONCLUSIONS
In septic patients, none of the dietary supplements had a substantial effect on mortality except for magnesium and vitamin C, which were linked to lower short-term mortality with low certainty of evidence. Further investigation into high-quality studies with the use of dietary supplements for sepsis should be highly discouraged.
Topics: Humans; Dietary Supplements; Sepsis; Network Meta-Analysis; Shock, Septic; Randomized Controlled Trials as Topic; Treatment Outcome; Length of Stay; Adult; Respiration, Artificial
PubMed: 38663051
DOI: 10.1016/j.clnu.2024.03.030 -
Evidence Report/technology Assessment Oct 2016To update a prior systematic review on the effects of omega-3 fatty acids (n-3 FA) on maternal and child health and to assess the evidence for their effects on, and...
OBJECTIVES
To update a prior systematic review on the effects of omega-3 fatty acids (n-3 FA) on maternal and child health and to assess the evidence for their effects on, and associations with, additional outcomes.
DATA SOURCES
MEDLINE®, Embase®, the Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Centre for Agriculture and Biosciences (CAB) Abstracts from 2000 to August 2015; eligible studies from the original report; and relevant systematic reviews.
REVIEW METHODS
We included randomized controlled trials (RCTs) of any defined dose of n-3 FA (or combination) compared to placebo, any other n-3 FA, or alternative dose with an outcome of interest conducted in pregnant or breastfeeding women or neonates (preterm or term). We also included prospective observational studies that analyzed the association between baseline n-3 FA intake or biomarker level and followup outcomes. Postnatal interventions began within a week of birth for term infants and within a week of beginning enteral or oral feeding for preterm infants. Standard methods were used for data abstraction and analysis, according to the Evidence-based Practice Center Methods Guide.
RESULTS
We identified 4,275 potentially relevant titles from our searches, of which 95 RCTs and 48 observational studies met the inclusion criteria. Risk of bias was a concern with both RCTs and observational studies. Outcomes for which evidence was sufficient to draw a conclusion are summarized here with the Strength of Evidence (SoE). (Outcomes for which the evidence was insufficient to draw a conclusion are summarized in Appendix G of the report.).
UNLABELLED
Maternal Exposures and Outcomes: Gestational length and risk for preterm birth: Prenatal algal docosahexaenoic acid (DHA) or DHA-enriched fish oil supplementation had a small positive effect on length of gestation (moderate SoE), but no effect on risk for preterm birth (low SoE). Prenatal EPA (eicosapentaenoic acid) plus DHA-containing fish oil supplementation has no effect on length of gestation (low SoE). Supplementation with DHA, or EPA plus DHA-, or DHA-enriched fish oil does not decreaserisk for preterm birth (low SoE).
UNLABELLED
Birth weight and risk for low birth weight: Changes in maternal n-3 FA biomarkers were significantly associated with birth weight. Prenatal algal DHA or DHA-enriched fish oil supplementation had a positive effect on birth weight among healthy term infants (moderate SoE), but prenatal DHA supplementation had no effect on risk for low birth weight (low SoE). Prenatal EPA plus DHA or alpha-linolenic acid (ALA) supplementation had no effect on birth weight (low SoE).
UNLABELLED
Risk for peripartum depression: Maternal n-3 FA biomarkers had no association with risk for peripartum depression. Maternal DHA, EPA, or DHA-enriched fish oil supplementation had no effect on risk for peripartum depression (low SoE).
UNLABELLED
Risk for gestational hypertension/preeclampsia: Prenatal DHA supplementation among high-risk pregnant women had no effect on the risk for gestational hypertension or preeclampsia (moderate SoE). Prenatal supplementation of any n-3 FA in normal-risk women also had no significant effect on risk for gestational hypertension or preeclampsia (low SoE).
UNLABELLED
Fetal, Infant, and Child Exposures and Outcomes: Postnatal growth patterns: Maternal fish oil or DHA plus EPA supplementation had no effect on postnatal growth patterns (attainment of weight, length, and head circumference) when administered prenatally (moderate SoE) or both pre- and postnatally (low SoE). Fortification of infant formulas with DHA plus arachidonic acid (AA, an n-6 FA) had no effect on growth patterns of preterm or term infants (low SoE).
UNLABELLED
Visual acuity: Prenatal supplementation with DHA had no effect on development of visual acuity (low SoE). Supplementing or fortifying preterm infant formula with any n-3 FA had no significant effect on visual acuity assessed by visual evoked potentials (VEP) at 4 or 6 months corrected age (low SoE). Data conflicted on the effectiveness of supplementing infant formula for term infants with n-3 FA depending on when and how visual acuity was assessed (i.e. by VEP or by behavioral methods) and the type of essential FA provided (low SoE).
UNLABELLED
Neurological development: Prenatal or postnatal n-3 FA supplementation had no consistent effect on neurological development (low SoE).
UNLABELLED
Cognitive development: Prenatal DHA supplementation with AA or EPA had no effect on cognitive development (moderate SoE). Supplementing breastfeeding women with DHA plus EPA also had no effect on cognitive development in infants and children (low SoE). Supplementing or fortifying preterm infants' formula with DHA plus AA had a positive effect on infant cognition at some short-term followup times (moderate SoE). Supplementing or fortifying infant formula for term infants with any n-3 FA had no effect on cognitive development (low SoE). Evidence is insufficient to support any effect of n-3 FA infant supplementation on long-term cognitive outcomes.
UNLABELLED
Autism spectrum disorder, attention deficit hyperactivity disorder (ADHD), and learning disorders: Maternal or infant n-3 FA supplementation had no effect on risk for autism spectrum disorders or ADHD (low SoE). No studies on other learning disorders were identified.
UNLABELLED
Atopic dermatitis (AD), allergies, and respiratory disorders: Pre- and postnatal (maternal and infant) n-3 FA supplementation had no consistent effect on the risk for AD/eczema, allergies, asthma, and other respiratory illnesses (moderate SoE). Biomarkers and intakes had no consistent association with the risk for AD, allergies, and respiratory disorders (low SoE).
UNLABELLED
Adverse events: Prenatal and infant supplementation with n-3 FA or fortification of foods with n-3 FA did not result in any serious or nonserious adverse events (moderate SoE); with the exception of an increased risk for mild gastrointestinal symptoms.
CONCLUSIONS
Most studies in this report examined the effects of fish oil (or other combinations of DHA and EPA) supplements on pregnant or breastfeeding women or the effects of infant formula fortified with DHA plus AA. As with the original report, with the exception of small increases in birth weight and length of gestation,n-3 FA supplementation or fortification has no consistent evidence of effects on peripartum maternal or infant health outcomes. No effects of n-3 FA were seen on gestational hypertension, peripartum depression, or postnatal growth. Apparent effects of n-3 FA supplementation were inconsistent across assessment methods and followup times for outcomes related to infant visual acuity, cognitive development and prevention of allergy and asthma. Future RCTs need to assess standardized preparations of n-3 and n-6 FA, using a select group of clinically important outcomes, on populations with baseline n-3 FA intakes typical of those of most western populations.
Topics: Birth Weight; Child Health; Dietary Supplements; Docosahexaenoic Acids; Eicosapentaenoic Acid; Fatty Acids, Omega-3; Fish Oils; Infant, Low Birth Weight; Maternal Health; Humans; Female; Infant, Newborn; Adult
PubMed: 30307735
DOI: 10.23970/AHRQEPCERTA224 -
Prostaglandins, Leukotrienes, and... Apr 2015This paper presents a systematic review of human studies investigating the effect of altering dietary omega-3 polyunsaturated fatty acid (n-3 PUFA) alpha-linolenic acid... (Review)
Review
The effect of modifying dietary LA and ALA intakes on omega-3 long chain polyunsaturated fatty acid (n-3 LCPUFA) status in human adults: a systematic review and commentary.
This paper presents a systematic review of human studies investigating the effect of altering dietary omega-3 polyunsaturated fatty acid (n-3 PUFA) alpha-linolenic acid (ALA) and omega-6 polyunsaturated fatty acid (n-6 PUFA) linoleic acid (LA) intakes on n-3 long-chain polyunsaturated fatty acid (LCPUFA) status in adult humans. The results suggest that it is possible to increase n-3 LCPUFA status by reducing LA and/or increasing ALA intake in humans, although decreasing LA intake to below 2.5%E may be required to specifically increase levels of the n-3 LCPUFA docosahexaenoic acid (DHA). The majority of studies in this area to date have been relatively poor in quality, which limits the ability to draw robust conclusions, and we present a series of recommendations to improve the quality of future studies in fatty acid nutrition in humans.
Topics: Adult; Clinical Trials as Topic; Dietary Fats, Unsaturated; Fatty Acids, Omega-3; Female; Humans; Linoleic Acid; MEDLINE; Male; alpha-Linolenic Acid
PubMed: 25687496
DOI: 10.1016/j.plefa.2015.01.001 -
International Journal of Environmental... Jun 2021Mastalgia, or breast pain, is common among women which can lead to significant impairment in daily living. Hence, finding an effective treatment that can alleviate the... (Meta-Analysis)
Meta-Analysis Review
Mastalgia, or breast pain, is common among women which can lead to significant impairment in daily living. Hence, finding an effective treatment that can alleviate the symptom is very important. Thus, we carry out this study to determine the efficacy of evening primrose oil (EPO) for mastalgia treatment in women. The review included published randomised clinical trials that evaluated EPO used for treating mastalgia against a placebo or other treatments, irrespective of the blinding procedure, publication status, or sample size. Two independent authors screened the titles and abstracts of the identified trials; full texts of relevant trials were evaluated for eligibility. Two reviewers independently extracted data on the methods, interventions, outcomes, and risk of bias. The random-effects model was used for estimating the risk ratios and mean differences with 95% confidence intervals. Thirteen trials with 1752 randomised patients were included. The results showed that EPO has no difference to reduce breast pain compared to topical NSAIDS, danazol, or vitamin E. The number of patients who achieved pain relief was no different compared to the placebo or other treatments. The EPO does not increase adverse events, such as nausea, abdominal bloating, headache or giddiness, increase weight gain, and altered taste compared to a placebo or other treatments. EPO is a safe medication with similar efficacy for pain control in women with mastalgia compared to a placebo, topical NSAIDS, danazol, or vitamin E.
Topics: Female; Humans; Linoleic Acids; Mastodynia; Oenothera biennis; Plant Oils; Randomized Controlled Trials as Topic; gamma-Linolenic Acid
PubMed: 34200727
DOI: 10.3390/ijerph18126295 -
The Cochrane Database of Systematic... Nov 2015Omega 6 plays a vital role in many physiological functions but there is controversy concerning its effect on cardiovascular disease (CVD) risk. There is conflicting... (Review)
Review
BACKGROUND
Omega 6 plays a vital role in many physiological functions but there is controversy concerning its effect on cardiovascular disease (CVD) risk. There is conflicting evidence whether increasing or decreasing omega 6 intake results in beneficial effects.
OBJECTIVES
The two primary objectives of this Cochrane review were to determine the effectiveness of:1. Increasing omega 6 (Linoleic acid (LA), Gamma-linolenic acid (GLA), Dihomo-gamma-linolenic acid (DGLA), Arachidonic acid (AA), or any combination) intake in place of saturated or monounsaturated fats or carbohydrates for the primary prevention of CVD.2. Decreasing omega 6 (LA, GLA, DGLA, AA, or any combination) intake in place of carbohydrates or protein (or both) for the primary prevention of CVD.
SEARCH METHODS
We searched the following electronic databases up to 23 September 2014: the Cochrane Central Register of Controlled Trials (CENTRAL) on the Cochrane Library (Issue 8 of 12, 2014); MEDLINE (Ovid) (1946 to September week 2, 2014); EMBASE Classic and EMBASE (Ovid) (1947 to September 2014); Web of Science Core Collection (Thomson Reuters) (1990 to September 2014); Database of Abstracts of Reviews of Effects (DARE) and Health Technology Assessment Database, and Health Economics Evaluations Database on the Cochrane Library (Issue 3 of 4, 2014). We searched trial registers and reference lists of reviews for further studies. We applied no language restrictions.
SELECTION CRITERIA
Randomised controlled trials (RCTs) of interventions stating an intention to increase or decrease omega 6 fatty acids, lasting at least six months, and including healthy adults or adults at high risk of CVD. The comparison group was given no advice, no supplementation, a placebo, a control diet, or continued with their usual diet. The outcomes of interest were CVD clinical events (all-cause mortality, cardiovascular mortality, non-fatal end points) and CVD risk factors (changes in blood pressure, changes in blood lipids, occurrence of type 2 diabetes). We excluded trials involving exercise or multifactorial interventions to avoid confounding.
DATA COLLECTION AND ANALYSIS
Two review authors independently selected trials for inclusion, extracted the data, and assessed the risk of bias in the included trials.
MAIN RESULTS
We included four RCTs (five papers) that randomised 660 participants. No ongoing trials were identified. All included trials had at least one domain with an unclear risk of bias. There were no RCTs of omega 6 intake reporting CVD clinical events. Three trials investigated the effect of increased omega 6 intake on lipid levels (total cholesterol, low density lipoprotein (LDL-cholesterol), and high density lipoprotein (HDL-cholesterol)), two trials reported triglycerides, and two trials reported blood pressure (diastolic and systolic blood pressure). Two trials, one with two relevant intervention arms, investigated the effect of decreased omega 6 intake on blood pressure parameters and lipid levels (total cholesterol, LDL-cholesterol, and HDL-cholesterol) and one trial reported triglycerides. Our analyses found no statistically significant effects of either increased or decreased omega 6 intake on CVD risk factors.Two studies were supported by funding from the UK Food Standards Agency and Medical Research Council. One study was supported by Lipid Nutrition, a commercial company in the Netherlands and the Dutch Ministry of Economic Affairs. The final study was supported by grants from the Finnish Food Research Foundation, Finnish Heart Research Foundation, Aarne and Aili Turnen Foundation, and the Research Council for Health, Academy of Finland.
AUTHORS' CONCLUSIONS
We found no studies examining the effects of either increased or decreased omega 6 on our primary outcome CVD clinical endpoints and insufficient evidence to show an effect of increased or decreased omega 6 intake on CVD risk factors such as blood lipids and blood pressure. Very few trials were identified with a relatively small number of participants randomised. There is a need for larger well conducted RCTs assessing cardiovascular events as well as cardiovascular risk factors.
Topics: Adult; Aged; Blood Pressure; Cardiovascular Diseases; Cholesterol; Cholesterol, HDL; Cholesterol, LDL; Fatty Acids, Omega-6; Female; Humans; Male; Middle Aged; Primary Prevention; Randomized Controlled Trials as Topic; Triglycerides
PubMed: 26571451
DOI: 10.1002/14651858.CD011094.pub2 -
Phytotherapy Research : PTR Oct 2021The evening primrose oil has prostaglandin effects and is applied to soften the cervix. This systematic review and meta-analysis aimed to establish the results of... (Meta-Analysis)
Meta-Analysis Review
The evening primrose oil has prostaglandin effects and is applied to soften the cervix. This systematic review and meta-analysis aimed to establish the results of clinical trials performed on the effect of evening primrose oil on labor induction and cervical ripening in pregnant women. Research studies were searched from 1990 to September 2019 in Pubmed, Science Direct, Embase, and Cochrane Library using the keywords: cervical ripening, Bishop score, labor induction, post-term pregnancy, evening primrose, and any possible combination of these keywords (Farsi, English). Data analysis was conducted using STATA (version 14.1), and I index and random effect forest plots to assess the heterogeneity between the studies and perform the meta-analysis, respectively. Six articles that met the inclusion criteria were extracted in which four were entered into quantitative meta-analysis. The results' high heterogeneity was 91.4% based on I index (p ≤ .001) and the random model was applied for meta-analysis. The result demonstrated no significant difference between the intervention and control groups in terms of mean difference of the Bishop score before and after intervention (SMD: 0.27, 95%CI: -0.41, 0.96, p = .43). Based on current meta-analysis on four studies, effectiveness of oral consumption of evening primrose on cervical ripening was not approved.
Topics: Cervical Ripening; Female; Humans; Labor, Induced; Linoleic Acids; Oenothera biennis; Plant Oils; Pregnancy; gamma-Linolenic Acid
PubMed: 33913585
DOI: 10.1002/ptr.7147 -
Canadian Journal of Diabetes Jun 2024Current medications for diabetic neuropathy (DN) recommended by the American Diabetes Association and American Academy of Neurology do not address the pathologic process... (Meta-Analysis)
Meta-Analysis
Ranking Alpha Lipoic Acid and Gamma Linolenic Acid in Terms of Efficacy and Safety in the Management of Adults With Diabetic Peripheral Neuropathy: A Systematic Review and Network Meta-analysis.
OBJECTIVES
Current medications for diabetic neuropathy (DN) recommended by the American Diabetes Association and American Academy of Neurology do not address the pathologic process of denervation among patients with DN, because ancillary treatments, such as reactive oxygen scavengers, may be needed. The purpose of this work was to summarize the available evidence about the efficacy and safety of alpha lipoic acid (ALA) and gamma linolenic acid (GLA) in the management of DN.
METHODS
Using the search terms [(alpha lipoic acid or ALA or thioctic acid or thioctacid) or (gamma linolenic acid or GLA)] AND [(diabetes or diabetes mellitus) AND (polyneuropathy or neuropathy or sensorimotor polyneuropathy or radiculopathy)], 11 studies were included in this review and combined meta-analysis.
RESULTS
Eight of the 11 articles (73%) reported significant benefit of ALA vs placebo. In the meta-analysis, the Total Symptom Score (TSS) for ALA 600 mg/day (ALA600) was 1.05 points lower (standard mean difference [SMD] -1.05, 95% confidence interval [CI] -2.07 to -0.04, p=0.04, I=98.18%) compared with control at the end of the study. In the network meta-analysis, ALA600 (SMD -1.68, 95% CI -2.8 to -0.6) and GLA (SMD -2.39, 95% CI -4.3 to -0.5) had significantly lower TSSs compared with placebo. Moreover, GLA had the highest probability of being the best (52.7%) for improving DN symptoms. In all studies, most adverse events include gastrointestinal disturbances. In terms of tolerability, no differences were detected between ALA and control groups.
CONCLUSION
ALA and GLA appear to be safe and efficacious biofactors for improvement of DN symptoms.
Topics: Humans; Thioctic Acid; Diabetic Neuropathies; gamma-Linolenic Acid; Network Meta-Analysis; Adult; Treatment Outcome; Antioxidants
PubMed: 38295879
DOI: 10.1016/j.jcjd.2024.01.007