BACKGROUND: Plant-based diets, often referred to as vegetarian diets, are associated with health benefits. However, the association with mortality is less clear.

OBJECTIVE: We investigated associations between plant-based diet indexes and all-cause and cardiovascular disease mortality in a nationally representative sample of US adults.

BACKGROUND:Beneficial effects of vegetarian and vegan diets on health outcomes have been supposed in previous studies. OBJECTIVES:Aim of this study was to clarify the association between vegetarian, vegan diets, risk factors for chronic diseases, risk of all-cause mortality, incidence and mortality from cardio-cerebrovascular diseases, total cancer and specific type of cancer (colorectal, breast, prostate and lung), through meta-analysis. METHODS:A comprehensive search of Medline, EMBASE, Scopus, The Cochrane Library and Google Scholar was conducted.

High consumption of red meat and processed meat has been associated with increased risk of several chronic diseases. We conducted a meta-analysis to summarize the evidence from prospective studies on red meat and processed meat consumption in relationship to all-cause mortality. Pertinent studies were identified by searching PubMed through May 2013 and by reviewing the reference lists of retrieved articles. Prospective studies that reported relative risks with 95% confidence intervals for the association of red meat or processed meat consumption with all-cause mortality were eligible.

A proportionate study was carried out of the causes of death of the 759 Vegetarian Society members whose deaths were recorded in Society records and whose death certificates could be traced. Compared to the general population, a lower proportion of deaths from respiratory diseases and from lung cancer was noted particularly in long-standing members, consistent with the evidence that vegetarians smoke less than the average.