Intake of legumes and cardiovascular disease: A systematic review and dose-response meta-analysis.

AIMS: To summarize the evidence on the association between the intake of legumes and the risk of cardiovascular disease (CVD) overall, coronary heart disease (CHD) and stroke, and to identify optimal intake levels for reduced disease risk through a systematic review and dose-response meta-analysis. DATA SYNTHESIS: We have systematically searched PubMed, Scopus and Web of Science up to March, 2022 for the retrieval of intervention and observational studies (PROSPERO Reg. number: CRD42021247565). Pooled relative risks (RRs) comparing extreme categories of intake were computed using random-effects models. One-stage dose-response meta-analyses were also performed using random-effects models. 22 831 articles were screened resulting in 26 eligible observational studies (21 prospective cohort and 5 case-control studies). When comparing extreme categories of intake, the consumption of legumes was inversely associated with CVD (n = 25: RR = 0.94; 95%CI:0.89,0.99) and CHD (n = 16: RR = 0.90; 95%CI:0.85,0.96), but not with stroke (n = 9: RR = 1.00; 95%CI:0.93,1.08). We further found evidence for an inverse dose-response association with CHD, increasing in magnitude up to an intake of 400 g/week, after which the benefit seems to level-off. CONCLUSIONS: The intake of legumes was associated with a reduced risk of CVD and CHD, but not with stroke, among individuals with the highest consumption levels. An intake level of 400 g/week seemed to provide the optimal cardiovascular benefit. Further research is needed to better understand the role of legumes in stroke subtypes.

Fish intake, n-3 fatty acid body status, and risk of cognitive decline: a systematic review and a dose-response meta-analysis of observational and experimental studies.

CONTEXT: Randomized controlled trials (RCTs) testing supplementation with eicosapentaenoic (EPA) and docosahexaenoic (DHA) fatty acids have failed to provide evidence supporting a suggested inverse association between fish intake and dementia risk. OBJECTIVE: Dose-response analyses were conducted to evaluate associations between fish intake, all-cause dementia or Alzheimer's Disease (AD), and the effect of EPA/DHA supplementation on cognitive performance. DATA SOURCES: PubMed, Scopus and Web of Science databases were searched for original research evaluating either associations between fish intake and dementia or AD, or the impact of EPA and/or DHA supplementation on the risk of cognitive decline. DATA EXTRACTION: Data were collected on study characteristics and methods; number of cases/deaths (for observational studies); categories of exposure; model covariates; risk estimates from the most-adjusted model; type and dosage of supplementation (from RCTs); fatty acid levels in blood; and differences in cognition test results before and after supplementation. Risk of bias was assessed through the ROBINS-E and RoB2.0 tools for observational and experimental studies, respectively. DATA ANALYSIS: Weighted mixed-effects models were applied, allowing for the inclusion of studies with 2 levels of exposure. Based on findings with low/moderate risk of bias, fish intake of up to 2 portions (250 g) per week was associated with a 10% reduction (95% confidence interval [CI]: 0.79, 1.02, Ν = 5) in all-cause dementia and a 30% reduction (95% CI: 0.54, 0.89, Ν = 3) in AD risk. Changes in EPA and DHA body status had a positive impact on participants' executive functions, but not on their overall cognitive performance. CONCLUSION: The protection offered by fish intake against cognitive decline levels off at intakes higher than 2 portions/week and likely relates to the impact of EPA and DHA on the individual's executive functions, although there remain questions about the mechanisms linking the short- and long-term effects. SYSTEMATIC REVIEW REGISTRATION: PROSPERO registration no. CRD42019139528.