In 2017, Italian researchers conducted a review of nearly one-hundred research studies that looked at the effect of vegan and/or vegetarian diets on a number of health outcomes. Since then, their report has been cited by hundreds of researchers and practitioners, and remained a key resource for dietary decision-making. Here’s what they found: 

Vegetarian Diets

Vegetarian diet: no meat (poultry, beef, fish, shellfish, etc.) 

The meta-analysis showed that those who adhere to vegetarian diets: 

  • Have reduced risk of ischemic heart disease (-25%)
  • Have reduced risk of cancer (-8%) 
  • Did not have a statistically significant difference in cardiovascular and cerebrovascular diseases or overall mortality

Vegan Diets

Vegan diet: no meat and no animal-derived products (e.g., eggs, dairy) 

The meta-analysis showed that those who stick to vegan diets: 

  • Have an even greater reduced risk of cancer than vegetarians (-15%)
  • Did not have a statistically significant difference in ischemic heart disease, cardiovascular and cerebrovascular diseases, or overall mortality


In regard to reducing cancer risk, both vegan and vegetarian diets are great options. A vegan diet may provide slightly more protective effects against cancer than a vegetarian diet. However, vegetarian diets provide an additional benefit of reduced ischemic heart disease risk.


Dinu, M., Abbate, R., Gensini, G. F., Casini, A., & Sofi, F. (2016). Vegetarian, vegan diets and multiple health outcomes: A systematic review with meta-analysis of observational studies. Critical Reviews in Food Science and Nutrition,57(17), 3640-3649. doi:10.1080/10408398.2016.1138447