Diet and depression

Just this week, I have seen three patients with depression requiring treatment. Treatment options include medications, therapy, and self-care. Self-care includes things like sleep, physical activity, and diet, and is just as important as meds and therapy — sometimes more so.

In counseling my patients about self-care, I always feel like we don't have enough time to get into diet. I am passionate about diet and lifestyle measures for good health, because there is overwhelming evidence supporting the benefits of a healthy diet and lifestyle for, oh, just about everything: preventing cardiovascular disease, cancer, dementia, and mental health disorders, including depression.

Diet and emotional well-being

Diet is such an important component of mental health that it has inspired an entire field of medicine called nutritional psychiatry. Mind-body medicine specialist Eva Selhub, MD has written a superb summary of what nutritional psychiatry is and what it means for you right here on this blog, and it's worth reading.

What it boils down to is that what we eat matters for every aspect of our health, but especially our mental health. Several recent research analyses looking at multiple studies support that there is a link between what one eats and our risk of depression, specifically. One analysis concluded:

"A dietary pattern characterized by a high intake of fruit, vegetables, whole grain, fish, olive oil, low-fat dairy and antioxidants and low intakes of animal foods was apparently associated with a decreased risk of depression. A dietary pattern characterized by a high consumption of red and/or processed meat, refined grains, sweets, high-fat dairy products, butter, potatoes and high-fat gravy, and low intakes of fruits and vegetables is associated with an increased risk of depression."

Which comes first? Poor diet or depression?

One could argue that, well, being depressed makes us more likely to eat unhealthy foods. This is true, so we should ask what came first, the diet or the depression? Researchers have addressed this question, thankfully. Another large analysis looked only at prospective studies, meaning, they looked at baseline diet and then calculated the risk of study volunteers going on to develop depression. Researchers found that a healthy diet (the Mediterranean diet as an example) was associated with a significantly lower risk of developing depressive symptoms.

So, how should I counsel my patients on diet? There are several healthy options that can be used as a guide. One that comes up again and again is the Mediterranean diet. Another wonderful resource for folks is the Harvard T.H. Chan School of Public Health website with an introductory guide to healthy diet.

The bottom line

The gist of it is, eat plants, and lots of them, including fruits and veggies, whole grains (in unprocessed form, ideally), seeds and nuts, with some lean proteins like fish and yogurt. Avoid things made with added sugars or flours (like breads, baked goods, cereals, and pastas), and minimize animal fats, processed meats (sorry, bacon), and butter. Occasional intake of these "bad" foods is probably fine; remember, everything in moderation. And, for those who are trying to lose weight, you can't go wrong with colorful fruits and veggies. No one got fat eating berries or broccoli. Quality matters over quantity. And when it comes to what we eat, quality really, really matters.

Resources

Dietary patterns and depression risk: A meta-analysis.Psychiatry Research, July 2017.

Diet quality and depression risk: A systematic review and dose-response meta-analysis of prospective studies. Journal of Affective Disorders, January 15, 2018.