How Does Diet Impact Mental Health?

As many of us are exploring the kitchen more, you may want to tune in to your body and how you are feeling. What we fuel ourselves with can majorly impact our systems, both physically and mentally. When dealing with conditions like anxiety and depression, research shows mood is impacted by what we eat. Conventional wisdom and science agree that increasing good habits and decreasing bad ones tend to have positive effects. But how do we define exactly what is “good” versus “bad”? When looking directly at our mental health and diet, where should we be leaning in and what should we leave on the shelf?

The typical “Western” diet contains mainstays like processed and refined foods at high rates. Comparing this style of eating to styles like the Mediterranean diet, where whole foods are key and meat and dairy consumption is lower show decreased rates of depression. For the most part, the Mediterranean focuses on adding specific things to your diet. For example, whole grains and legumes for starch cravings, high volumes of vegetables and fruits to keep you full, fatty fish instead of red meat, and healthy fats from raw nuts and oils that are naturally liquid at room temperature like olive oil. Sweets are okay to be enjoyed in moderation with this lifestyle. One study found that within three weeks, transitioning to a diet including the traits of the Mediterranean diet had a positive effect on depression scores.¹

Gut Health

With so many factors in play that could impact our health, it is hard to definitively pinpoint the answer of what makes the difference. However, we know that the dietary impact on factors like gut health, inflammation, and how we absorb nutrients and energy from food is vast. What we know about gut health (which at this point is far less than what is still unknown) is that our gut microbiome is vital to our body in a much broader manner than just protecting the intestinal tract. Serotonin, which impacts both mood and sleep, is mostly synthesized in the gut. It could be impactful that diets more similar to the Mediterranean style of eating do a better job of keeping a healthy bacterial balance thriving in the gut.

Brain Health

Another study focused on how diet impacts the hippocampus, the portion of your brain which creates new neurons in the process known as neurogenesis. Many antidepressants have a positive effect on neurogenesis. This process has been linked to both mood and cognition. It is known that certain stimuli, including both high fat and sugar diets, alcohol use and opioids, inhibit neurogenesis. Conversely, diets can promote better neurogenesis, namely those rich in polyunsaturated fatty acids (PUFAs) which come from foods like walnuts, flax seeds, fatty fish, as well as foods containing curcumin like turmeric and polyphenols found in some seasonings, cocoa powder, berries, fruits, vegetables, nuts and beans. Exercise, caloric balance and continued learning also promote neurogenesis.³

What About Sugar?

Sugar intake has been found to increase depression rates. In a study of over 23,000 individuals, it was found that male subjects who ate the most sugar, quantified as greater than 67g per day (for reference, a 20oz bottle of Coca Cola contains 65g of sugar), were 23% more likely to develop depression or anxiety in the following 5 year period than those in the bottom third of subjects who consumed fewer than 40g of sugar a day (a 12 oz can of Coca Cola contains 39g).² In other research, it has been suggested that too much sugar decreases the protein BDNF, or brain-derived neurotrophic factor, which is involved in the development of disorders like depression and anxiety.4

What You Can Do

Whatever the reason, research focusing on nutrition and mental health shows promise in utilizing the Mediterranean diet, or at least components of it. We can’t say that changing your diet will miraculously change your mental health without other intervention, but incorporating new dietary habits into your life may be worth exploring in conjunction with your mental healthcare routine including therapy, medication, exercise and self-care. It is important that you work with your mental health providers to establish a safe, healthy plan for your care. There is little harm in taking steps to change your diet and see how you feel. You may be pleasantly surprised by how altering what you eat impacts your well-being overall. Keep track of changes you notice and if you find it has positive effects for you, it may be worth a more permanent change. Regardless of how it ultimately works, oftentimes we must rely on the fact that if it works, it works.


  1. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0222768
  2. https://www.nature.com/articles/s41598-017-05649-7
  3. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2775886/
  4. https://www.ncbi.nlm.nih.gov/pubmed/12088740