Dietary factors and onset of natural menopause: A systematic review and meta-analysis.

BACKGROUND: Diet has been suggested to play a role in determining the age at natural menopause; however, the evidence is inconsistent. OBJECTIVE: We systematically reviewed and evaluated published research about associations between diet and onset of natural menopause (ONM). METHODS: We searched 6 databases (Medline, Embase, Cochrane, PubMed, Web of Science and Google Scholar) through January 21,2021 to identify prospective studies assessing the association between diet and ONM. Two independent reviewers extracted data using a predesigned data-collection form. Pooled hazard risks (HRs) were calculated using random effect models. RESULTS: Of the 6,137 eligible references we reviewed, we included 15 articles in our final analysis. Those 15 articles included 91,554 women out of 298,413 who experienced natural menopause during follow-up. Overall, there were 89 food groups investigated, 38 macronutrients and micronutrients, and 6 dietary patterns. Among the food groups, higher intake of green and yellow vegetables was associated with earlier age of ONM, while high intakes of some dairy products, such as low-fat, skimmed milk, and low intake of alcohol were associated with a later onset. We observed no consistent association between macronutrient and micronutrient intake and ONM. Our results suggests that a vegetarian diet could be associated with early ONM; we did not observe any other consistent effect from other dietary patterns. Limitations included the number of studies, lack of replication studies and the research being of an observational nature; most studies (11/15) were at medium risk of bias. CONCLUSION: Although some food items were associated with ONM, the overall evidence about associations between diet and ONM remains controversial. Prospero id: CRD42021232087.

Oat Intake and Risk of Type 2 Diabetes, Cardiovascular Disease and All-Cause Mortality: A Systematic Review and Meta-Analysis.

Cardiovascular disease (CVD) and type 2 diabetes (T2D) remain the top disease and mortality burdens worldwide. Oats have been shown to benefit cardiovascular health and improve insulin resistance. However, the evidence linking oat consumption with CVD, T2D and all-cause mortality remains inconclusive. We conducted a comprehensive systematic review and meta-analysis of prospective cohort studies to evaluate the associations between oat consumption and risks of T2D, CVD and all-cause mortality in the general population. Five electronic databases were searched until September, 2020. Study specific relative risks (RR) were meta-analyzed using random effect models. Of 4686 relevant references, we included 9 articles, based on 8 unique studies and 471,157 participants. Comparing oat consumers versus non-consumers, RRs were 0.86 (95% CI 0.72-1.03) for T2D incidence and 0.73 (95% CI 0.5-1.07) for combined CVD incidence. Comparing participants with highest versus lowest oat intake, RRs were 0.78 (95% CI 0.74-0.82) for T2D incidence, 0.81 (95% CI 0.61-1.08) for CHD incidence and 0.79 (95% CI 0.59-1.07) for stroke. For all-cause mortality one study based on three cohorts found RR for men and women were 0.76 (95% CI 0.69-0.85) and 0.78 (95% CI 0.70-0.87), respectively. Most studies (n = 6) were of fair to good quality. This meta-analysis suggests that consumption of oat could reduce the risk for T2D and all-cause mortality, while no significant association was found for CVD. Future studies should address a lack of standardized methods in assessing overall oat intake and type of oat products, and investigate a dose-dependent response of oat products on cardiometabolic outcomes in order to introduce oat as preventive and treatment options for the public.