BackgroundThere have been mixed results reported internationally when associating vegetarian dietary patterns with all-cause and cause-specific mortalities. ObjectiveTo extend our previous results by evaluating, with a larger number of deaths (N=12515), cause-specific mortalities comparing different vegetarian types to non-vegetarians. MethodsThis prospective study used data from the Adventist Health Study-2 cohort. Mortality was ascertained between study baseline, 2002-2007 and follow-up through 2015. Dietary data were collected at baseline using a validated quantitative food frequency questionnaire and then categorized into five dietary patterns: non-vegetarian, semi-vegetarian, pesco-vegetarian, lacto-ovo-vegetarian, and vegan. Main outcomes and measures include all-cause and cause-specific mortalities using Cox proportional hazards regression models and competing risk methods. ResultsThe analytic sample included 88400 participants who provided 971424 person-years of follow-up. We report results as estimated at ages 65 and 85 years due to age-dependence of many hazard ratios (HR’s). Compared to non-vegetarians, vegetarians had lower risks of mortality (HR’s and 95% confidence interval – 95% CI at age 65; followed by same at age 85 years in parentheses), overall (0.89[0.83,0.95];0.98[0.91,1.04]), from renal failure (0.52[0.38,0.70]; 0.65[0.55,0.76]), infectious disease (0.57[0.40,0.82];0.90[0.70,1.17]), diabetes (0.51[0.33,0.78]; 0.69[0.53,0.88]), select cardiac (0.75[0.65,0.87]; 0.89[0.83,0.95]), and ischemic heart disease causes (0.730.59,0.90]; 0.84[0.75,0.94]). Vegans, lacto-ovo-vegetarians and pesco-vegetarians were also observed to have lower risks of total mortality and several similar cause-specific mortalities. However, higher cause-specified neurological mortalities were observed among older vegetarians (estimated at age 85 years), specifically stroke (HR=1.17[1.02,1.33]), dementia (HR=1.13[1.00,1.27]), and Parkinson’s Disease (HR=1.37[0.98,1.91]). Results in Black subjects for vegetarian/nonvegetarian comparisons largely followed the same trends, but HR’s were less precise due to smaller numbers. ConclusionsVegetarian diets are associated with lower risk for all-cause and many cause-specific mortalities, especially among males and in younger subjects. However, higher risks were observed among older vegetarians for stroke and dementia. These results need further support and investigation.