Vegans and vegetarians who consume packaged and processed alternatives to meat are more prone to depression, a new one to learn has found.
Researchers at Bond University in Queensland found that a poor plant-based diet can lead to poorer mental health compared to a diet high in fresh produce.
Nutritional psychiatric researcher Megan Lee said the finding was particularly significant given the increasing popularity of the vegan and vegetarian lifestyles and the proliferation of packaged foods targeting these groups.
Processed foods are high in refined vegetable oils, grains, salt, and sugar.
“There is a common belief that a plant-based diet is inherently healthy, but like any diet, it depends on what you put in your mouth,” Lee said.
“Vegans and vegetarians don’t automatically eat loads of fruits and vegetables because there are all these products that are fully processed, fully refined.
“People can inadvertently consume large amounts of processed plant-based foods, which is a known risk factor for heightened depression.”
During the study, researchers looked at the diet and mental health of 219 vegans and vegetarians aged 18 to 44 across the country, who were then asked to fill out appropriate questionnaires.
Researchers found that those who had lots of fresh fruits, vegetables, nuts, seeds, legumes, and whole grains in their diets were less at risk of depression than those who ate substandard food.
The link between diet and the risk of depression is likely due to the presence of complex carbohydrates, fiber, probiotics, and antioxidants, all of which reduce symptoms of depression, Lee said.
“It seems to have more of a protective function,” she said.
“Our research has not found that a plant-based diet is a treatment or solution for those who are already depressed.”
Vegans and vegetarians are already more prone to depression than the general population, Lee added.
“We believe this (susceptibility to depression) could be because vegans and vegetarians are more aware of external issues – animal welfare, environmental concerns – and may be socially ostracized because of their diet choices,” she said.
Research also found that meat eaters can also protect their mental health by consuming more fruits and vegetables.
Across Australia, more than 2.5 million people have chosen to live meat-free.