Can your diet actually impact your depression or bipolar disorder? This is the question. While people claim that certain diets do help with mental illnesses like depression and bipolar disorder, the evidence just hasn’t been there. About the only thing the research can say is that eating an unhealthy, processed diet can lead to nutrient deficiencies and this can make mental illness outcomes worse. That’s it. And that makes perfect sense. But can your diet actually improve your bipolar disorder, depression or other mental health issue? Here’s what we know today.

Diet Improves Physical Health and that Impacts Mental Health

Of course, we know that a better diet makes us look and feel better in general. We also know that those with a mental illness who also have non-mental illnesses have increased morbidity and mortality. Things like medication side effects and lifestyle factors can also contribute to poor physical health of those with bipolar, depression or other mental illnesses.

If this is the case then, perhaps a diet can, indirectly at least, positively impact one’s mental health.

Diet, Bipolar and Depression — Nutritional Psychiatry

Yes, there is now a branch of psychiatry called “nutritional psychology.” This is good for all of us. It means there are people specifically looking into the relationship between diet and how we feel emotionally.

First, a warning: It’s incredibly important to remember that any nutritional intervention used to improve mental illness will likely only help people with mild-to-moderate mental illness symptoms. If you are severely ill, these steps may be supportive but you absolutely need medication too.

According one new trial (the Supporting the Modification of lifestyle in Lowered Emotional States [SMILES] trial), specific food did, indeed, improve mood. Another study conducted a systematic review and meta-analysis of observational studies and it showed that healthier diet seemed to protect against depressive symptoms.

Mental Illness, Diet and the Gut-Brain Connection

Many, many people have screamed that 90% of serotonin receptors are in the gut so, of course, food controls mental illness. And while the number “90%” is true, just because the serotonin receptors exist in the gut, it doesn’t mean that’s what’s controlling mental illness. For no other reason, we know this because we know that mental illnesses are incredibly complex and serotonin levels are just a tiny part of what contributes to mental illness.

All that said, it appears that the gut environment (known as the microbiome), is affected by what we eat, specifically becoming inflamed when eating highly-processed foods. This inflammation can lead to symptoms of different disorders (not necessarily mental illness ones). The findings from a recent study suggest that reducing processed foods from our diets would help reduce the likelihood of diseases related to inflammation.

Probiotics and Prebiotics

One way to protect one’s microbiome is to include probiotic and prebiotic foods in your diet. (A prebiotic is a soluble fiber that helps feed the good organisms [probiotics] in the gut. Probiotics already live inside the large intestine.) You eat the prebiotic and this gives food for the probiotic to eat and this makes them work more efficiently.

Can diet improve bipolar or depression? Read this article for evidence on the best diet for bipolar disorder, depression and other mental illness.

No, this doesn’t mean you should run out and buy supplements that cost a fortune. If you want to do that, you should contact a doctor and see if the cost is really worth it for you.

What this does mean, though, is that eating the right foods can support a healthy microbiome. Again, this won’t necessarily improve mental illness symptoms, but it may make you healthier overall.

According to a Psychiatric Times article, examples of prebiotic foods include onions, leeks, asparagus, bananas, Jerusalem artichokes (sunchokes), chicory root, garlic and dandelion greens. According to the same article, probiotic foods that supply these bacteria include fermented foods such as sauerkraut, yogurt with active cultures, pickles, kefir, kimchi, kombucha and miso.

What’s the Best Diet for People with Bipolar or Depression?

What seems to come up over and over again for health promotion in all areas is the Mediterranean diet. This diet “focuses on eating whole grains, seafood and poultry at least twice a week; consuming beans, legumes, fresh fruit, and leafy greens (spinach, kale, arugula, romaine), nuts (almonds, walnuts), cruciferous vegetables (cauliflower, broccoli), healthy fats (olive and canola oil), and less red meat.”

In other words, not what the typical American eats.

What Should People with Bipolar Disorder or Depression Eat?

The specific guidelines found in Psychiatric Times with regards to what mental illness patients should eat are:

  • Eat whole foods and avoid packaged or processed foods.
  • Think of eating an orange rather than drinking orange juice to avoid added sugars.
  • Instead of a vegetable juice, consider increasing your daily servings of fruits and vegetables.
  • Include probiotic-rich foods such as yogurt (avoid fruit-based yogurt, which is high in unwanted sugars).
  • Eat foods rich in fiber.
  • Replace sugary desserts with a serving of fresh fruit and dark chocolate.
  • Avoid processed and packaged foods that are high in food additives that disrupt the healthy bacteria in the gut.

Best Antidepressant Foods

I consider the above to be the best advice for the diet of those with bipolar disorder, major depressive disorder or another mental illness. That said, there’s a bit more to be known about food that have specific antidepressant properties.

Twelve antidepressant nutrients related to the prevention and treatment of depressive disorders have been identified. They are: folate, iron, long-chain omega-3 fatty acids (EPA and DHA), magnesium, potassium, selenium, thiamine, vitamin A, vitamin B6, vitamin B12, vitamin C and zinc. Because these nutrients have been identified, it’s possible to point to specific foods and food groups that support provides these nutrients the best.

According to Antidepressant Foods: An Evidence-Based Nutrient Profiling System for Depression, the animal-based foods that have the most antidepressant-type effect are:

  • Oysters
  • Liver and other organ meats
  • Poultry giblets
  • Clams
  • Mussels
  • Octopus
  • Crab
  • Goat

Plant-based foods that have the most antidepressant-type effect include:

  • Watercress
  • Spinach
  • Mustard, turnip or beet greens
  • Lettuces
  • Swiss chard
  • Herbs
  • Chicory greens
  • Pummelo*
  • Peppers
  • Kale or collards

It is decidedly worth noticing that all of the plant-based items have a greater antidepressant-type effect than any of the animal-based items. (See the whole list along with each item’s “ranking” here.)

* Please note that pummelo (also spelled pomelo) is related to the grapefruit. This means it has the same deleterious effects on some medication that grapefruit does. If you don’t know if grapefruit will interact with your medication, steer clear (trust me) or find out from your doctor or a pharmacist now. If you should stay away from grapefruit, you should stay away from pummelo too. See more here.

Best Antidepressant Food Groups

Finally, when food groups are reviewed, they are antidepressant-type effects in the following order (greater effect listed first):

  • Vegetables
  • Organ meats
  • Fruits
  • Seafood
  • Legumes
  • Meat
  • Grains
  • Nuts and seeds
  • Dairy

You can see why the Mediterranean diet is the one most recommended given the above.

It should also be noted that, based on all of the above, cutting out a food group entirely is not warranted and, in my opinion, not a good idea. This means that drastic diets that do this are likely not a good choice for people with mental illness or at least depression.

More on Diets for Depression, Bipolar and Other Mental Illness

For more information on the best diet for bipolar, depression and other mental illnesses, see these references:

  1. Naidoo, Umadevi MD. “Nutritional Psychiatry: The Gut-Brain Connection.” Psychiatric Times. Jan. 17, 2019.
  2. LaChance, Laura R, and  Ramsey, Drew. “Antidepressant foods: An evidence-based nutrient profiling system for depression.” World Journal of Psychiatry. Sep. 20, 2018.