Can Vegetarian Diets Cause Depression?

There are many reasons you might consider becoming a vegetarian. Ample evidence suggests plant-based diets can reduce your risk of heart disease, obesity, diabetes, and even certain cancers. They’re environmentally “greener.” (If you’d like a sobering fact, livestock production, including meat, milk, and eggs, accounts for one-third of the world’s fresh water consumption and 14.5 percent of global greenhouse gas emissions.) Furthermore, and this one gets interesting, primarily plant-based diets can even alter your gut microbiome composition to better mitigate the harmful effects of red meat.

While there’s a wealth of research into the physical health and environmental benefits of vegetarian diets, there are still a lot of unknowns when it comes to mental health.

That was the purpose of a new study which is making headlines this month after suggesting there could actually be a link between vegetarian diets and depression.

Vegetarian Diets and Depression

Before we delve into the study results, it’s important to point out there are several sizable problems with this study. First, it only looked at men, and thus, the results can only apply to half of the population. The researchers also can’t rule out that people who are already depressed or have other mental health conditions could be more likely to become vegetarian for various reasons. After all, it’s not uncommon to treat mental illness through dietary changes. Finally, there’s no insight into what kinds of foods these vegetarians were eating. What was their fresh produce intake in comparison to more processed foods? We don’t know.

Now, the results. The study, which looked at data from 9,700 men participating in research on parent and child health, found that the 350 men who self-identified as vegetarian or vegan were more likely to also identify a higher depression score than their omnivore counterparts.

What could be causing the difference? The researchers suspected it could be nutritional deficiencies. Following an imbalanced vegetarian diet could lead to deficiencies in key nutrients. Omega-3 fatty acids, vitamin B12, iron, and zinc deficiencies are all associated with depression and can be difficult to maintain solely from plant-based foods without extra supplementation. Additionally, vegetarian diets might be higher in things like omega-6 fatty acids, which can cause inflammation and possibly depression with it.

Arivale’s Take

While the results of the study are interesting, the flaws are too great for us to embrace. Not only are the results irrelevant for half the population, the researchers cannot prove causation—only a link.

Here’s what we do know.

Plant-based diets can be very impactful on your physical health, but fueling your body with adequate nutrients is always going to be crucial—no matter if you’re eating meat or not. That’s why in addition to coaching, we look at an extensive array of blood markers, including omega-3 fatty acids, B12, iron, and zinc. This gives us much more insight into what’s actually happening in your body, how it might relate to the foods you eat, and finally, what you can do about it.