tofu veggiesSome ex-vegans say that they became depressed on a plant-based diet. If they did, it was probably due to poor food choices and maybe a lack of recommended supplements. It’s doubtful that a healthy vegan diet promotes depression. In fact, eating more plant foods may have a few advantages for people who suffer from this chronic illness.

Is it possible, though, that vegans are more likely to suffer from depression for a completely different reason?

One small study suggests that vegans and vegetarians respond with more empathy (as measured by brain scans) when they view either animal or human suffering (1). And, not surprisingly, it’s possible that heightened empathy raises risk for depression (2).

Whether or not these findings are true, if you happen to be a vegan who suffers from depression, a few tweaks to your diet may help. In my book Vegan for Her, I devoted a whole chapter to the relationship of food choices to depression. Since that book was published, there has been even more research on the subject.

A word of caution, though: If you currently use counseling or meds to manage your depression, you should not abandon these in favor of a dietary approach—at least not without involving your health care provider. (And you should never stop taking antidepressants abruptly or without medical supervision.) But the dietary choices that may reduce risk for depression are pretty simple ones and are healthful options for anyone. It can’t hurt to give them a try as part of your overall plan for dealing with depression.

Is Depression a Disease of Inflammation?

It’s long been suspected that inflammation raises risk for depression (3). Vegans and others who eat plant-based diets may have the edge here since these food patterns are associated with lower levels of pro-inflammatory compounds (4-6).

Oxidative stress can also increase inflammation so it makes sense that eating plenty of antioxidant-rich foods like fruits, vegetables and nuts, could reduce depressive symptoms (7,8). You don’t need to eat some special “anti-inflammation” diet, though. Just eat lots of whole plant foods, avoid trans fats and limit refined carbs.

Fish, Fat and Depression

A new meta-analysis from China touting the benefits of eating fish for reducing depression has been getting a lot of press (9). If there is anything particularly beneficial about fish, it’s probably the omega-3 fats DHA and EPA. For those who suffer from depression, it could be a good idea to add these fats to your diet. But it doesn’t mean that you need to eat fish. The DHA and EPA in vegan supplements derived from microalgae are the same as the ones in salmon and sardines. In fact, this is where the salmon and sardines get their omega-3s.

Other sources of fat may have benefits as well. Polyphenols in olive oil have important anti-inflammatory properties and one olive oil metabolite, oleamide, is being studied for treatment of both sleeping and mood disorders. In the EPIC-Greece study, for example, people who ate more olive oil were less likely to be depressed (10). It doesn’t mean you have to add olive oil to your diet, but it might be good to choose it more often than other added fats.

Supplements and Depression

Low vitamin D, which is linked to depression, can be a problem for people eating any type of diet (11,12). Vegans get vitamin D the same way that most other people do—from sun exposure, fortified foods or supplements. Although certain fish provide vitamin D, it’s not likely that people can eat enough to meet needs. If you live far from the equator, it’s likely that you need to supplement.

Inadequate intakes of both vitamin B12 and the B-vitamin folate are related to depression, possibly through effects on blood homocysteine levels (13). Vegans usually get plenty of folate which is abundant in certain fruits and vegetables and in legumes. We absolutely need to supplement with vitamin B12, however.

Protein-Rich Plants for Reducing Depression

Protein-rich plant foods like legumes and some nuts are good sources of the amino acid tryptophan which is needed to make serotonin. Low serotonin levels are linked to depression. There is no evidence, though, that tryptophan supplements help, and vegans who eat healthy diets get plenty of tryptophan anyway. Although cow’s milk is touted for its tryptophan content, a cup of soymilk or a half-cup of black beans has about the same amount.

Including soyfoods in your diet may also help with depression, although it’s not because of the protein in these foods. Soybeans contain phytoestrogens called isoflavones that sometimes (although not always) have estrogen-like effects. Since estrogen may alleviate symptoms of depression in post-menopausal women, it’s not surprising that isoflavones could have similar effects.

In a study in Japan, 25 milligrams of isoflavones (about the amount in a cup of soymilk) significantly reduced depression in postmenopausal women over an 8 week period (14). In fact, in a small pilot study, isoflavones were as effective as anti-depressants like Zoloft in postmenopausal women. Isoflavones plus medication was best of all (15).

So far, these kinds of results have been seen only in postmenopausal women, and the research should be considered preliminary. But if you like soyfoods and you deal with depression, it makes sense to include these foods in your diet. (Note that many veggie meats made from soy don’t contain much in the way of isoflavones.)

A Depression-Fighting Diet Plan

A vegan diet aimed at reducing risk of depression is really just a plain old healthy vegan diet. And while a healthy diet isn’t a cure-all for all types of depression, there is no downside to adopting any of these habits.

  • Eat plenty of protein-rich beans.
  • Consider including traditional soyfoods like soymilk, tofu and tempeh in your diet. Just one serving per day may be enough.
  • Eat lots of fruits and vegetables.
  • Minimize refined carbs.
  • When you cook with added fats, consider using good quality extra-virgin olive oil
  • Supplement with vitamin B12, vitamin D (unless you are absolutely certain that you have adequate sun exposure) and a vegan supplement of DHA and EPA.
 References
  1. The brain functional networks associated to human and animal suffering differ among omnivores, vegetarians and vegans. Filippi M, Riccitelli G, Falini A, et al. PLoS One 2010;5:e10847.
  2. Guilt, fear, submission, and empathy in depression. O’Connor LE, Berry JW, Weiss J, Gilbert P. J Affect Disord 2002;71:19-27.
  3. So depression is an inflammatory disease, but where does the inflammation come from? Berk M, Williams LJ, Jacka FN, et al. BMC Med 2013;11:200.
  4. C-reactive protein and nutrition. Krajcovicova-Kudlackova M, Blazicek P. Bratisl Lek Listy 2005;106:345-7.
  5. Effects of a long-term vegetarian diet on biomarkers of antioxidant status and cardiovascular disease risk. Szeto YT, Kwok TC, Benzie IF. Nutrition 2004;20:863-6.
  6. Mediterranean diet, endothelial function and vascular inflammatory markers. Esposito K, Ciotola M, Giugliano D. Public Health Nutr 2006;9:1073-6.
  7. Dietary factors and low-grade inflammation in relation to overweight and obesity. Calder PC, Ahluwalia N, Brouns F, et al. Br J Nutr 2011;106 Suppl 3:S5-78.
  8. Mediterranean dietary pattern and depression: the PREDIMED randomized trial. Sanchez-Villegas A, Martinez-Gonzalez MA, Estruch R, et al. BMC Med 2013;11:208.
  9. Fish consumption and risk of depression: a meta-analysis. Li F, Liu X, Zhang D. J Epidemiol Community Health 2015.
  10. Dietary lipids and geriatric depression scale score among elders: the EPIC-Greece cohort. Kyrozis A, Psaltopoulou T, Stathopoulos P, Trichopoulos D, Vassilopoulos D, Trichopoulou A. J Psychiatr Res 2009;43:763-9.
  11. Vitamin D intake and mental health-related quality of life in older women: the Iowa Women’s Health Study. Motsinger S, Lazovich D, MacLehose RF, Torkelson CJ, Robien K. Maturitas 2012;71:267-73.
  12. Serum 25-hydroxyvitamin D and depressive symptoms in older women and men. Milaneschi Y, Shardell M, Corsi AM, et al. J Clin Endocrinol Metab 2010;95:3225-33.
  13. The homocysteine hypothesis of depression. Folstein M, Liu T, Peter I, et al. Am J Psychiatry 2007;164:861-7.
  14. Low-dose isoflavone aglycone alleviates psychological symptoms of menopause in Japanese women: a randomized, double-blind, placebo-controlled study. Hirose A, Terauchi M, Akiyoshi M, Owa Y, Kato K, Kubota T. Arch Gynecol Obstet 2015.
  15. Effects of antidepressants and soybean association in depressive menopausal women. Estrella RE, Landa AI, Lafuente JV, Gargiulo PA. Acta Pol Pharm 2014;71:323-7