Adopting a vegetarian or vegan diet can have its benefits, especially in fighting off cardiovascular risks, lowering cholesterol, and cutting the risk for obesity.
Mentally, however, it can be a different story.
A recent study found that, in an all-male sample group, symptoms of depression were more common for self-proclaimed vegetarians or vegans.
In conducting the study, researchers took data from male partners of pregnant women in the Avon Longitudinal Study of Parents and Children (ALSPAC), including their diets and Edinburgh Post Natal Depression Scale (EPDS).
Adjusting for socioeconomic status and other variables including age, marital status, employment, religion, and alcohol consumption, among others, researchers assessed the data outcomes and found vegetarians (only 3.6 percent of the sample) had a higher depression score on average than non-vegetarians.
Vegetarians and vegans could possibly be more prone to depression because their intake of certain omega-3 fatty acids and vitamin B12 is lower than people who subscribe to meat-eating diets. Authors said deficiencies in those areas are often linked to depression, as well as for levels of iron and zinc.
Additionally, vegetarians and vegans tend to consume more omega-6 fatty acids — such as nuts, wheat, or veggie oils — which can increase inflammation and have shown associations with depression.
The study also suggests a chicken-or-the-egg scenario, meaning it’s not yet clear whether vegetarianism causes depression, or if depressed people are more likely to be vegetarian — or if both are true.
Authors also don’t rule out eating disorders as a component to this correlation.
“It is possible that for some proportion of the population, vegetarianism is not chosen for health, religious, or ethical reasons, but is a marker for other psychiatric disorders manifesting with symptoms of both eating disorders and depressive symptoms,” the authors write in the study discussion.
Because the research pool was limited to only men, more studies are needed before a conclusive correlation between vegetarian/vegan diets and depression becomes clear.