People who follow a vegetarian lifestyle have around twice as many depressive episodes as those who eat meat, according to the Brazilian Longitudinal Study of Adult Health.

What to Know

• The high incidence of depression among vegetarians is not caused by nutrition but possibly by several factors, including the vegetarian social experience; depression itself may increase the likelihood of becoming vegetarian, or both vegetarianism and depression may be associated with guilt through factors involving the meat industry.
• Adopting a vegetarian diet might affect one’s relationship with others and involvement in social activities and may sometimes be associated with teasing or other forms of social ostracism.
• It is possible that being depressed and dwelling on negative thoughts cause people to be more likely to become vegetarian rather than the other way around.
• Videos depicting violence and cruelty in the meat industry may affect depressed people, causing them to dwell on the images, feel guilty for their part in creating the demand for meat, and become vegetarian.
• Survey data were collected in Brazil, a country famous for its meat-heavy diet, and while there has been a sharp increase in vegetarianism, vegetarians still account for less than 0.5%.