Cardiovascular disease mortality and cancer incidence in vegetarians: a meta-analysis and systematic review.
BACKGROUND
Prospective cohort studies have examined mortality and overall cancer incidence among vegetarians, but the results have been inconclusive.


OBJECTIVE
The objective of the present meta-analysis was to investigate cardiovascular disease mortality and cancer incidence among vegetarians and nonvegetarians.


METHODS
Medline, EMBASE and Web Of Science databases were searched for cohort studies published from inception to September 2011. Studies were included if they contained the relative risk (RR) and corresponding 95% CI. Participants were from the UK, Germany, California, USA, the Netherlands and Japan.


RESULTS
Seven studies with a total of 124,706 participants were included in this analysis. All-cause mortality in vegetarians was 9% lower than in nonvegetarians (RR = 0.91; 95% CI, 0.66-1.16). The mortality from ischemic heart disease was significantly lower in vegetarians than in nonvegetarians (RR = 0.71; 95% CI, 0.56-0.87). We observed a 16% lower mortality from circulatory diseases (RR = 0.84; 95% CI, 0.54-1.14) and a 12% lower mortality from cerebrovascular disease (RR = 0.88; 95% CI, 0.70-1.06) in vegetarians compared with nonvegetarians. Vegetarians had a significantly lower cancer incidence than nonvegetarians (RR = 0.82; 95% CI, 0.67-0.97).


CONCLUSIONS
Our results suggest that vegetarians have a significantly lower ischemic heart disease mortality (29%) and overall cancer incidence (18%) than nonvegetarians.
Department of Food Science and Nutrition, Zhejiang University, Hangzhou, China.
Tao
T
Huang
Bin
B
Yang
Jusheng
J
Zheng
Guipu
G
Li
Mark L
ML
Wahlqvist
Duo
D
Li
D002140:California / Q000453:epidemiology; D002318:Cardiovascular Diseases / Q000401:mortality*; D016208:Databases, Factual; D014676:Diet, Vegetarian; D005858:Germany / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D009369:Neoplasms / Q000401:mortality*; D009426:Netherlands / Q000453:epidemiology; D006113:United Kingdom / Q000453:epidemiology