A look at the powerful influence of diet on the brain

The Important Link Between Nutrition and Mental Health

March 1, 2023

Work, relationships, finances, and responsibilities place ongoing stress on our mental attention, often leaving us starved for balance. To compensate, we sleep less, work harder, stuff emotions, and may even self-medicate with substances, entertainment, food, or other unhealthy coping mechanisms. With so many strikes against our brains it is not surprising that depression and anxiety are on the rise each year as our brains try to keep up with overstimulation, negative thought patterns, and unhealthy diets.

With our brains always working, they require a constant fuel supply, which comes directly from the food we eat. The brain operates optimally on high-quality foods, with life-giving nutrients from vitamins, minerals, and antioxidants. Because our bodies best absorb nutrients through our diet, choosing foods rich in these key nutrients can help prevent depression and have optimal brain health. Unfortunately, eating low-quality foods, like highly refined, processed foods rich in salt, fat, and sugar, can impair the brain, increasing risk of depression and other mental health conditions.[i]

The Relationship of Serotonin, Dopamine, and Norepinephrine and Diet

Serotonin, dopamine, and norepinephrine are three key neurotransmitters our brain is reliant upon for positive mental health and optimal function. Serotonin helps us remain calm under stress, be less irritable, and elevates our mood. Norepinephrine helps us focus, concentrate, and have energy. And dopamine helps us enjoy the usual activities of life and experience pleasure. Many factors upset the natural ability of the human brain to produce these important chemicals, often leading to depression, anxiety, and other negative mental health consequences.

While medications alter how our brains use these important neurotransmitters, they will never help our bodies make more neurotransmitters. There are numerous lifestyle approaches to improving our brains, such as sunlight or exercise, but one of the most fundamental avenues is proper brain nutrition. Research shows us that diet can prevent depression and serve as an effective treatment for depression and other mental health conditions. [ii]

Simply taking any of these three neurotransmitters supplementarily cannot get them into your brain because they do not cross the blood-brain-barrier on their own. Instead, our brains make these neurotransmitters from important substrates that can cross the blood-brain barrier. Several tiny dietary proteins, known as amino acids, serve as building blocks for neurotransmitters.

Tryptophan: Serotonin’s Building Block  

The amino acid tryptophan is needed to create the neurotransmitter serotonin. Low levels of serotonin are associated with depression and other mood disorders. It is therefore important to get enough tryptophan in our diets and brain to experience the positive mental health benefits of serotonin.  

  • Tryptophan recommendation: 1,000-4,000 mg daily
  • Foods rich in tryptophan: oats, tofu, flaxseeds, walnuts, sunflower seeds, sesame seeds, chia seeds, seaweed, and pumpkin seeds

Tyrosine: Dopamine and Norepinephrine’s Building Block  

Tyrosine is another amino acid used by the brain to create dopamine and norepinephrine. In addition, sufficient folate and vitamin B12 are necessary to make adequate amounts of norepinephrine. Tyrosine helps improve stress, fatigue, sleepiness, and mood.  

  • Tyrosine recommendation: 1,000-2,000 mg daily
  • Foods rich in tyrosine: mustard greens, pumpkin seeds, sunflower seeds, almonds, green soybeans, tofu, sun dried tomatoes, watermelon, sweet potatoes, and seaweed  

Tryptophan and Tyrosine Have Competition

It’s a bit more complicated than just eating tryptophan and tyrosine to make more neurotransmitters. Even once in the body, other large neutral amino acids compete with tryptophan and tyrosine to cross the blood-brain barrier. However, whole-grain food sources of complex carbohydrates induce muscles to uptake large competing neutral amino acids, thus improving tryptophan and tyrosine access to the brain. As a result, carbohydrates increase brain tryptophan and tyrosine absorption and therefore increase serotonin, dopamine, and norepinephrine.  

Tryptophan is the least abundant amino acid in the diet. The popular notion that eating turkey will raise brain tryptophan and serotonin is false. [iii] Protein alone will not raise our brain concentration of these crucial, large amino acids–a diet rich in complex carbs is necessary.

Other Important Nutrients

Several other dietary nutrients are also important for biochemical processes of the brain and body for combating depressive symptoms and improving mental health.

  • Folate, 1,000 mcg/daily: black-eyed peas, lentils, black beans, asparagus, mustard greens, and spinach
  • Zinc, 20 mg/daily: pumpkin seeds, wild rice, pine nuts, and sunflower seeds
  • Magnesium, 420-2,000 mg/daily: soy milk, peanuts, black beans, and spinach
  • Omega-3, plant-based, 3,000 mg/daily: ground flax and chia seeds, walnuts, edamame, pecans, avocados, and blueberries  

Now is the Time to Improve Your Diet and Your Brain

Once nutrients cross the blood-brain barrier, our brains can create a sufficient supply of mood-enhancing neurotransmitters. But note that after adopting a plant-based diet, it can take seven to ten days to notice a difference in how you feel. Continued gradual improvement takes place as you replace damaging food constituents like arachidonic acid, cholesterol, and saturated fat with brain-enhancing nutrients. Now is the time to improve mental health through changing diet! Eating a plant-based diet rich in a wide-variety of colorful fruits and vegetables, grains, and nuts is a recipe for combatting depression and anxiety while boosting mental performance. When you commit to adding these important nutrients to your diet you will soon enjoy the lasting positive benefits!


[i] Godos, J., Bonaccio, M., et al. (2023). Ultra-Processed Food Consumption and Depressive Symptoms in a Mediterranean Cohort. Nutrients, 15(3), 504.

[ii]Opie, R. S., Itsiopoulos, C., et al. (2017). Dietary recommendations for the prevention of depression. Nutritional Neuroscience, 20(3), 161–171.

[iii] Young S. N. (2007). How to increase serotonin in the human brain without drugs. Journal of Psychiatry & Neuroscience : JPN, 32(6), 394–399.

About the author

Cami Gotshall, MPH, is the Health Education Director for Nedley Health. Cami's concentration in public health is nutrition and wellness– specifically making nutrition relevant and practical. Her passion is disseminating information on living a mentally healthy lifestyle to people around the world. Cami works closely with the Nedley Health programs to continually enhance and expand each program. She lives in Colorado with her husband.

Neil Nedley, MD, is a practicing physician in internal medicine. He has given numerous mental and emotional health educational lectures to physicians and caregivers of all specialties for attendees to receive the top category 1 of American Medical Association continuing medical education credits. He has served as an adjunct clinical professor of medicine at Loma Linda University and has been the clinical instructor. Dr. Nedley has presented and published numerous scientific studies in the medical literature and is well known internationally as a public speaker, teacher, and author.