Objective: To examine and quantify the potential dose-response relationship between red and processed meat consumption and risk of all-cause, cardiovascular and cancer mortality. Design: We searched MEDLINE, Embase, ISI Web of Knowledge, CINHAL, Scopus, the Cochrane library and reference lists of retrieved articles up to 30 November 2014 without language restrictions. We retrieved prospective cohort studies that reported risk estimates for all-cause, cardiovascular and cancer mortality by red and/or processed meat intake levels. The dose-response relationships were estimated using data from red and processed meat intake categories in each study. Random-effects models were used to calculate pooled relative risks and 95 % confidence intervals and to incorporate between-study variations. Results: Nine articles with seventeen prospective cohorts were eligible in this metaanalysis, including a total of 150 328 deaths. There was evidence of a non-linear association between processed meat consumption and risk of all-cause and cardiovascular mortality, but not for cancer mortality. For processed meat, the pooled relative risk with an increase of one serving per day was 1·15 (95 % CI 1·11, 1·19) for all-cause mortality (five studies; P < 0·001 for linear trend), 1·15 (95 % CI 1·07, 1·24) for cardiovascular mortality (six studies; P < 0·001) and 1·08 (95 % CI 1·06, 1·11) for cancer mortality (five studies; P < 0·001). Similar associations were found with total meat intake. The association between unprocessed red meat consumption and mortality risk was found in the US populations, but not in European or Asian populations. Conclusions: The present meta-analysis indicates that higher consumption of total red meat and processed meat is associated with an increased risk of total, cardiovascular and cancer mortality.

Observational studies have suggested that the intake of flavonoids is associated with a decreased risk of CVD. However, the results of these studies remain controversial. The aim of the present study was to evaluate the association between dietary flavonoid intake and CVD risk by conducting a systematic review of prospective cohort studies. Electronic reference databases were searched to identify studies that met the pre-stated inclusion criteria. The studies were assessed for eligibility and data were extracted by two authors independently. For each study, relative risks (RR) and 95 % CI were extracted and pooled using either a fixed-effects or a random-effects model. Generalised least-squares trend estimation analysis was used to evaluate dose-response relationships. The inclusion criteria were met by fourteen prospective cohort studies. The intakes of anthocyanidins (RR 0·89, 95 % CI 0·83, 0·96), proanthocyanidins (RR 0·90, 95 % CI 0·82, 0·98), flavones (RR 0·88, 95 % CI 0·82, 0·96), flavanones (RR 0·88, 95 % CI 0·82, 0·96) and flavan-3-ols (RR 0·87, 95 % CI 0·80, 0·95) were inversely associated with the risk of CVD when comparing the highest and lowest categories of intake. A similar association was observed for flavonol intake and CVD risk. Sensitivity and subgroup analyses further supported this association. The summary RR for CVD for every 10 mg/d increment in flavonol intake was 0·95 (95 % CI 0·91, 0·99). The present systematic review suggests that the dietary intakes of six classes of flavonoids, namely flavonols, anthocyanidins, proanthocyanidins, flavones, flavanones and flavan-3-ols, significantly decrease the risk of CVD.