A couple of months ago, a study on depression among male vegetarians made the social media rounds (1). I know from the flurry of emails I received that many vegans were alarmed by the findings. As is often the case, though, the headlines were far more dramatic than the actual findings.
The subjects were a small group of self-identified vegans and vegetarians, many of whom turned out to be nothing of the kind. In fact, 5% of the vegetarians and 72% of the vegans (72 percent!) said they currently consume some red meat. They were also just as likely as the omnivores in the study to consume fatty fish and shellfish. So I don’t know – maybe the study showed that depression is more common among people who think they are vegetarian but aren’t at all.
The researchers concluded that the study doesn’t resolve questions about whether vegetarian diets increase or decrease risk of depression. But, they suggested that possible risks in a vegetarian diet could be low intakes of omega-3 fats (the ones found in fatty fish) and vitamin B12. They also pointed to low intakes of folate as a potential culprit, but that doesn’t make sense since vegetarians are likely to have folate intakes that are at least as high as meat-eaters if not higher (2).
One of the study authors was involved in a different study published just around the same time. It compared people in the UK eating one of three types of diet: a vegetarian pattern, a traditional British pattern (described as a “meat and two veg” diet), or a pattern that emphasized processed foods and sweets (3). This study failed to find any differences in rates of depression among these different groups.
Other studies have found that people eating healthier plant-based diets (particularly those that emphasize fruits, veggies and fish) have less depression than those who eat more western type diets (4-6). One explanation could be lower levels of inflammation associated with plant-based diets, since chronic inflammation may be a risk factor for depression in some people (7-9).
At any rate, figuring out causation is tricky in studies of diet and depression. For example, diets high in processed foods are linked to depression, but maybe it’s because people who are depressed gravitate toward unhealthy comfort foods. When we look at cross-sectional studies (which examine the link between diet and depression at a particular moment in time) it’s hard to tell if people are eating Oreos and Fritos because they’re depressed or if they’re depressed because they’re eating Oreos and Fritos.
Still, the evidence allows us to make some dietary recommendations for vegans who suffer from depression. It may be that plant-based diets have advantages for reducing depression, but those advantages are sometimes cancelled out by shortfalls of vitamin B12 and omega-3 fats. I shared guidelines for vegans who suffer from depression a few years ago, and I think they are still relevant. You can see that there’s nothing fancy here; it’s really just about eating a healthy vegan diet –one that minimizes refined carbohydrates; emphasizes healthy fats, fruits and vegetables; and ensures adequate vitamins B12 and D. Which are all things you should do whether you suffer from depression or not.
Keep in mind, though, that it’s not all about diet. In the vegan world, we tend to put a lot of emphasis on food, sometimes forgetting that there are other factors that are equally (or possibly more) important. These include exercise, stress management, social engagement, getting adequate sleep – things that are important for everyone but maybe especially animal activists.
Finally, some vegans who suffer from depression need therapy or medication to manage it. To suggest that anyone suffering from depression just isn’t eating right is unfair, unkind, and unsupported by scientific evidence. Tweaking your diet to make it a little bit healthier (and especially making sure you are meeting nutrient needs) can be helpful in dealing with depression. It’s not a proven cure, though, and we need to always take a cautious and compassionate approach in talking about ways to manage depression and other mental health problems.
Hibbeln JR, Northstone K, Evans J, Golding J. Vegetarian diets and depressive symptoms among men. J Affect Disord 2018;225:13-17.
Davey GK, Spencer EA, Appleby PN, Allen NE, Knox KH, Key TJ. EPIC-Oxford: lifestyle characteristics and nutrient intakes in a cohort of 33 883 meat-eaters and 31 546 non meat-eaters in the UK. Public Health Nutr 2003;6:259-69.
Northstone K, Joinson C, Emmett P. Dietary patterns and depressive symptoms in a UK cohort of men and women: a longitudinal study. Public Health Nutr 2017:1-7.
Nanri A, Kimura Y, Matsushita Y, Ohta M, Sato M, Mishima N, Sasaki S, Mizoue T. Dietary patterns and depressive symptoms among Japanese men and women. Eur J Clin Nutr 2010;64:832-9.
Rienks J, Dobson AJ, Mishra GD. Mediterranean dietary pattern and prevalence and incidence of depressive symptoms in mid-aged women: results from a large community-based prospective study. Eur J Clin Nutr 2013;67:75-82.
Lai JS, Hiles S, Bisquera A, Hure AJ, McEvoy M, Attia J. A systematic review and meta-analysis of dietary patterns and depression in community-dwelling adults. Am J Clin Nutr 2014;99:181-97.
Raison CL, Miller AH. Is depression an inflammatory disorder? Curr Psychiatry Rep 2011;13:467-75.
Lucas M, Chocano-Bedoya P, Schulze MB, Mirzaei F, O’Reilly EJ, Okereke OI, Hu FB, Willett WC, Ascherio A. Inflammatory dietary pattern and risk of depression among women. Brain Behav Immun 2014;36:46-53.
Haghighatdoost F, Bellissimo N, Totosy de Zepetnek JO, Rouhani MH. Association of vegetarian diet with inflammatory biomarkers: a systematic review and meta-analysis of observational studies. Public Health Nutr 2017;20:2713-2721.