scholarly journals Protective effects of dietary PUFA against chronic disease: evidence from epidemiological studies and intervention trials

2013 ◽  
Vol 73 (1) ◽  
pp. 73-79 ◽  
Author(s):  
Thomas A. B. Sanders

This review considers evidence for a protective effect of PUFA on chronic disease. Estimates of PUFA intakes in prospective cohort studies are usually based on FFQ or biomarkers of intake. Cohort studies suggest that both linoleic and linolenic acid intake are associated with a lower risk of CHD. The intake of fish, the major source of long-chainn-3 PUFA is associated with a lower risk of both stroke and CHD, particularly sudden cardiac death. No relationship with common sites of cancer (breast and colon) and PUFA has been found. However, some recent studies suggest an association of high intakes ofn-3 PUFA with risk of prostate cancer. An updated Cochrane review of dietary fat modification (replacing SFA with PUFA) randomised controlled trials to prevent CHD found a 14 % lower incidence and a non-significant 7 % lower mortality from CHD. The effects of an increased intake ofn-3 PUFA on CHD incidence mortality have been tested in patients with pre-existing CHD in randomised controlled trials. Meta-analysis of these trials showed no overall benefit on total mortality or CVD incidence but a trend for lower risk of cardiac death was 0·91 (95 % CI 0·85, 0·98). At present, there is little evidence from other trials demonstrating the clear benefits or harm from increased intakes of PUFA. In conclusion, present evidence intakes benefit from partial replacement of SFA with a balanced mixture ofn-6 andn-3 PUFA which may contribute to CVD prevention.

2020 ◽  
Vol 30 (Supplement_5) ◽  
Author(s):  
T O'Dowd

Abstract Background Worldwide smoking remains the leading cause of preventable morbidity and mortality. Electronic cigarettes (ECs) are increasingly used by tobacco smokers as an aid to smoking cessation; however, their efficacy remains uncertain. Methods Electronic databases, clinical trial registries and grey literature sources were searched. The aim was to examine randomised controlled trials or prospective cohort studies, published since the 2016 Cochrane review on this topic, that assessed the efficacy of ECs in achieving smoking cessation among current smokers. Results Two RCTs and five cohort studies, including a total of 16,460 participants, were eligible for inclusion. One RCT found sustained 1-year abstinence of 18.0% in the EC group versus 9.9% in the nicotine replacement therapy group (RR: 1.83; 95% CI 1.30 to 2.58; P < 0.001). The second RCT did not find a statistically significant difference in abstinence rates between EC users and non-users (RR 0.71). Of the five included cohort studies, four reported statistically significant RRs. Two found a positive association (RRs of 1.45 and 1.84) between EC use and smoking cessation but two studies showed EC use was associated with reduced smoking cessation (RRs of 0.25 and 0.35). Due to significant heterogeneity between the studies the data were deemed unsuitable for pooling into a meta-analysis. All trials assessing smoking reduction reported higher rates of reduction among EC users. No serious adverse events were reported with EC use. Follow-up periods of included trials ranged from one to four years, with an average of 1.6 years. Conclusions There is limited, low-quality evidence that ECs are an effective intervention for smoking cessation and smoking reduction. The overall quality of evidence is low as it is based on a small number of studies with inconsistent and imprecise results. Due to the short follow-up periods of the included trials, the long-term safety of ECs is unclear from this review. Key messages Limited evidence that electronic cigarettes are an effective smoking cessation intervention. Further well-designed randomised controlled trials are required to investigate the efficacy of ECs for smoking cessation.


BMJ Open ◽  
2018 ◽  
Vol 8 (3) ◽  
pp. e020623 ◽  
Author(s):  
Kirthi Menon ◽  
Aya Mousa ◽  
Barbora de Courten

IntroductionAgeing of populations globally, coupled with the obesity epidemic, has resulted in the rising prevalence of chronic diseases including diabetes, cardiovascular diseases, cancers and neurodegenerative disorders. Prevention of risk factors that contribute to these diseases is key in managing the global burden of chronic diseases. Recent studies suggest that carnosine, a dipeptide with anti-inflammatory, antioxidative and antiglycating properties may have a role in the prevention of chronic diseases; however, no previous reviews have examined the effects of carnosine and other histidine-containing peptides (HCDs) on chronic disease risk factors and outcomes. We aim to conduct a comprehensive systematic review to examine the effects of supplementation with carnosine and other HCDs on chronic disease risk factors and outcomes and to identify relevant knowledge gaps.Methods and analysisElectronic databases including Medline, Cumulative Index of Nursing and Allied Health, Embase and all Evidence-Based Medicine will be systematically searched to identify randomised controlled trials (RCTs) and systematic reviews of RCTs, comparing supplementation with carnosine and/or other HCDs versus placebo, usual care or other pharmacological or non-pharmacological interventions. One reviewer will screen titles and abstracts for eligibility according to prespecified inclusion criteria, after which two independent reviewers will perform data extraction and quality appraisal. Meta-analyses, metaregression and subgroup analyses will be conducted where appropriate.Ethics and disseminationEthics approval is not required as this review does not involve primary data collection. This review will generate level-one evidence regarding the effects of carnosine supplementation on chronic disease risk factors and outcomes and will be disseminated through peer-reviewed publications and at conference meetings to inform future research on the efficacy of carnosine supplementation for the prevention of chronic diseases.PROSPERO registration numberCRD42017075354.


BMJ ◽  
2019 ◽  
pp. l352 ◽  
Author(s):  
Hannah A Wilson ◽  
Rob Middleton ◽  
Simon G F Abram ◽  
Stephanie Smith ◽  
Abtin Alvand ◽  
...  

AbstractObjectiveTo present a clear and comprehensive summary of the published data on unicompartmental knee replacement (UKA) or total knee replacement (TKA), comparing domains of outcome that have been shown to be important to patients and clinicians to allow informed decision making.DesignSystematic review using data from randomised controlled trials, nationwide databases or joint registries, and large cohort studies.Data sourcesMedline, Embase, Cochrane Controlled Register of Trials (CENTRAL), and Clinical Trials.gov, searched between 1 January 1997 and 31 December 2018.Eligibility criteria for selecting studiesStudies published in the past 20 years, comparing outcomes of primary UKA with TKA in adult patients. Studies were excluded if they involved fewer than 50 participants, or if translation into English was not available.Results60 eligible studies were separated into three methodological groups: seven publications from six randomised controlled trials, 17 national joint registries and national database studies, and 36 cohort studies. Results for each domain of outcome varied depending on the level of data, and findings were not always significant. Analysis of the three groups of studies showed significantly shorter hospital stays after UKA than after TKA (−1.20 days (95% confidence interval −1.67 to −0.73), −1.43 (−1.53 to −1.33), and −1.73 (−2.30 to −1.16), respectively). There was no significant difference in pain, based on patient reported outcome measures (PROMs), but significantly better functional PROM scores for UKA than for TKA in both non-trial groups (standard mean difference −0.58 (−0.88 to −0.27) and −0.29 (−0.46 to −0.11), respectively). Regarding major complications, trials and cohort studies had non-significant results, but mortality after TKA was significantly higher in registry and large database studies (risk ratio 0.27 (0.16 to 0.45)), as were venous thromboembolic events (0.39 (0.27 to 0.57)) and major cardiac events (0.22 (0.06 to 0.86)). Early reoperation for any reason was higher after TKA than after UKA, but revision rates at five years remained higher for UKA in all three study groups (risk ratio 5.95 (1.29 to 27.59), 2.50 (1.77 to 3.54), and 3.13 (1.89 to 5.17), respectively).ConclusionsTKA and UKA are both viable options for the treatment of isolated unicompartmental osteoarthritis. By directly comparing the two treatments, this study demonstrates better results for UKA in several outcome domains. However, the risk of revision surgery was lower for TKA. This information should be available to patients as part of the shared decision making process in choosing treatment options.Systematic review registrationPROSPERO number CRD42018089972.


2011 ◽  
Vol 70 (4) ◽  
pp. 494-505 ◽  
Author(s):  
Thomas Reinehr

Therapy of choice in obese children and adolescents is lifestyle intervention based on nutrition education, behavioural treatment and exercise treatment. Its efficacy even after the end of intervention has been proven by several randomised-controlled trials and meta-analyses including a recent Cochrane review. However, randomised-controlled trials are likely to overestimate the effectiveness. Studies under normal day-to-day circumstances demonstrated only a very moderate effect on weight loss (<10% success rate 2 years after the onset of intervention). A reduction of >0·5 SDS-BMI (which means a stable weight over 1 year in growing children) is associated with an improvement of cardiovascular risk factors, while improvements of quality of life seem independent of the degree of weight loss. Younger children and less overweight children particularly profit from lifestyle interventions in contrast to extremely obese adolescents. Recent studies demonstrated that involving parents is crucial for success, suggesting that parents and children and not children alone should be the primary target of interventions. Failures in weight reduction are attributed not only to a lack of motivation but also to other aspects particular to the genetic background. The techniques, more than the contents, of an intervention influence the treatment outcome. Besides behavioural therapy, systemic and solution-focused treatments are important. Future longitudinal research should focus on the identification of which children and adolescents profit from which kind of intervention, in order to be able to tailor specific treatment approaches. Studies under normal day-to-day circumstances are necessary to prove the benefit of this kind of intervention.


2016 ◽  
Vol 116 (3) ◽  
pp. 381-389 ◽  
Author(s):  
Norman J. Temple

AbstractLarge numbers of randomised controlled trials (RCT) have been carried out in order to investigate diet–disease relationships. This article examines eight sets of studies and compares the findings with those from epidemiological studies (cohort studies in seven of the cases). The studies cover the role of dietary factors in blood pressure, body weight, cancer and heart disease. In some cases, the findings from the two types of study are consistent, whereas in other cases the findings appear to be in conflict. A critical evaluation of this evidence suggests factors that may account for conflicting findings. Very often RCT recruit subjects with a history of the disease under study (or at high risk of it) and have a follow-up of only a few weeks or months. Cohort studies, in contrast, typically recruit healthy subjects and have a follow-up of 5–15 years. Owing to these differences, findings from RCT are not necessarily more reliable than those from well-designed prospective cohort studies. We cannot assume that the results of RCT can be freely applied beyond the specific features of the studies.


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