Linking diet & depression

When we examine the link between diet and depression, it can be a bit tricky to know if people were eating potato chips and Oreos because they were depressed, or if they were depressed because they were eating potato chips and Oreos.

Despite this, there is still enough evidence that allows us to make some dietary recommendations for those who suffer from depression.

It’s not all about diet (but it can help)

There are other factors that are equally important when dealing with depression: exercise, stress management, social networks, good quality sleep, and medication if required.

To imply that anyone suffering from depression “just isn’t eating right” is both unfair and unsupported by scientific evidence, and that’s not what I am saying here.

What I am saying is that small improvements to diet can certainly impact mood, hormone, and brain function in positive, healthy ways.

Depression & inflammation

There has been a lot of information in the past 10 years linking inflammation and risk for depression (see reference #1 at bottom). Those with a plant-based diet and others who include a significant amount of fruit, vegetables, and grains may have a bit of an edge since this way of eating is associated with foods that are anti-inflammatory.

It makes sense that eating plenty of vegetables and fruits, which are high antioxidant foods, could reduce inflammation and potentially the symptoms of depression (references 2, 3, 4, 5).

Vitamin D

Many of us have low levels of vitamin D, which is linked to depression, no matter what diet we are eating (reference #6). For those of who don’t leave near the equator and may be spending part of the year in the dull and dreary greyness (says she who lives on Vancouver Island), supplementation is easy and inexpensive.

Healthy fats

Omega 3 fatty acids DHA and EPA have received a lot of attention in the past decade. Adding these fats to the diet is beneficial for most people, not just those who suffer from depression.

These fats can be found in fish of course (particularly salmon and sardines), but also in chia, walnuts, flax, and microalgae. I know, algae, right? But if you think about it, algae is where the salmon and sardines get their omega 3’s, so you are kind of eating the middle man. Still not convinced? Let’s talk.

Olive oil is another source of beneficial fat with its lovely anti-inflammatory polyphenols, and it’s being studied as treatment for mood disorders. The EPIC-Greece study showed that people who ate more olive oil were less likely to be depressed (reference #7). (I am sure it has nothing to do with the fact that they lived in Greece, probably near a fabulous beach.)

Positively protein

The amino acid tryptophan, which is found in protein rich foods, is needed to make the hormone serotonin. Low serotonin levels are also linked to depression.

It’s unclear that supplementing with tryptophan alleviates symptoms, so food sources are generally best. The good news is that tryptophan is not just about the turkey: it’s easily added through chocolate (yes please), eggs, beans, nuts, seeds, and tofu as well.

So what’s the plan?

Nothing fancy here: a diet that reduces the risk of depression is really just about eating healthy. Adopting a healthy diet is not a cure-all of course, but there is certainly no downside to it.

If you need help developing a healthy diet that will work for you, I would love to chat.

References & further reading

1. So depression is an inflammatory disease, but where does the inflammation come from? Berk M, Williams LJ, Jacka FN, et al. BMC Med2013;11:200.
2. C-reactive protein and nutrition. Krajcovicova-Kudlackova M, Blazicek P. Bratisl Lek Listy 2005;106:345-7.
3. 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.
4. Mediterranean diet, endothelial function and vascular inflammatory markers. Esposito K, Ciotola M, Giugliano D. Public Health Nutr2006;9:1073-6.
5. Dietary factors and low-grade inflammation in relation to overweight and obesity. Calder PC, Ahluwalia N, Brouns F, et al. Br J Nutr2011;106 Suppl 3:S5-78.
6. Vitamin D and Depression: Where is all the Sunshine? Sue Penckofer, PhD, RN, Joanne Kouba, PhD, RD, Mary Byrn, BSN, RN, and  Carol Estwing Ferrans, PhD, RN, FAAN. Issues Ment Health Nurs. Author manuscript; available in PMC 2011 Jun 1.
7. Mediterranean dietary pattern and depression: the PREDIMED randomized trial. Sanchez-Villegas A, Martinez-Gonzalez MA, Estruch R, et al. BMC Med 2013;11:208.