title: Vegetarian diet and all-cause mortality: Evidence from a large population-based Australian cohort - the 45 and Up Study.
abstract: The vegetarian diet is thought to have health benefits including reductions in type 2 diabetes, hypertension, and obesity. Evidence to date suggests that vegetarians tend to have lower mortality rates when compared with non-vegetarians, but most studies are not population-based and other healthy lifestyle factors may have confounded apparent protective effects. The aim of this study was to evaluate the association between categories of vegetarian diet (including complete, semi and pesco-vegetarian) and all-cause mortality in a large population-based Australian cohort. The 45 and Up Study is a cohort study of 267,180 men and women aged ≥45years in New South Wales (NSW), Australia. Vegetarian diet status was assessed by baseline questionnaire and participants were categorized into complete vegetarians, semi-vegetarians (eat meat≤once/week), pesco-vegetarians and regular meat eaters. All-cause mortality was determined by linked registry data to mid-2014. Cox proportional hazards models quantified the association between vegetarian diet and all-cause mortality adjusting for a range of potential confounding factors. Among 243,096 participants (mean age: 62.3years, 46.7% men) there were 16,836 deaths over a mean 6.1years of follow-up. Following extensive adjustment for potential confounding factors there was no significant difference in all-cause mortality for vegetarians versus non-vegetarians [HR=1.16 (95% CI 0.93-1.45)]. There was also no significant difference in mortality risk between pesco-vegetarians [HR=0.79 (95% CI 0.59-1.06)] or semi-vegetarians [HR=1.12 (95% CI 0.96-1.31)] versus regular meat eaters. We found no evidence that following a vegetarian diet, semi-vegetarian diet or a pesco-vegetarian diet has an independent protective effect on all-cause mortality.
authors.affiliation: Prevention Research Collaboration, School of Public Health, Sydney Medical School, University of Sydney, NSW, Australia. Electronic address: seema.mihrshahi@sydney.edu.au.
authors.forename: Seema
authors.initials: S
authors.lastname: Mihrshahi
authors.affiliation: Prevention Research Collaboration, School of Public Health, Sydney Medical School, University of Sydney, NSW, Australia.
authors.forename: Ding
authors.initials: D
authors.lastname: Ding
authors.affiliation: Prevention Research Collaboration, School of Public Health, Sydney Medical School, University of Sydney, NSW, Australia.
authors.forename: Joanne
authors.initials: J
authors.lastname: Gale
authors.affiliation: School of Life and Environmental Sciences, Charles Perkins Centre, University of Sydney, Sydney, NSW, Australia.
authors.forename: Margaret
authors.initials: M
authors.lastname: Allman-Farinelli
authors.affiliation: National Centre for Epidemiology and Population Health, Australian National University, Canberra, ACT, Australia; The Sax Institute, Sydney, NSW, Australia.
authors.forename: Emily
authors.initials: E
authors.lastname: Banks
authors.affiliation: Prevention Research Collaboration, School of Public Health, Sydney Medical School, University of Sydney, NSW, Australia.
authors.forename: Adrian E
authors.initials: AE
authors.lastname: Bauman
mesh_terms: D001315:Australia; D015331:Cohort Studies; D014676:Diet, Vegetarian / Q000145:classification*; D005260:Female; D006801:Humans; D008019:Life Style; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009026:Mortality; D012042:Registries; D012307:Risk Factors; D011795:Surveys and Questionnaires
keywords: Diet; Mortality; Non-vegetarian; Pesco-vegetarian; Semi-vegetarian; Vegetarian