Does the food you eat really affect your mood? Does diet have a role in depression, anxiety, substance abuse and other psychiatric disorders? The research, while still in its infancy, is pointing to yes.

To start with the basics, on any given day, water and dietary intake can affect the mood of any individual. Skipping meals can cause irritability, fatigue and even anger, while overeating can lead to feelings of guilt, sadness, emotional distress and depression. The essential principles to avoid these negative uncomfortable feelings are: eat a balanced meal every 4 to 6 hours with small snacks in between if needed. A balanced meal consists of a grain or starch (sweet potato, rice, quinoa), a protein (fish, chicken, tofu or legume) and of course fruits and vegetables.

However, we can dig a lot deeper to see how foods may contribute to brain activity far beyond this. We have all heard of the “happy brain chemicals”, like dopamine and serotonin. But what are they really? They are neurotransmitters or nerve chemicals that regulate many of our functions including memory, appetite, mood and sleep. Neurotransmitters are made up of amino acids and amino acids are the building blocks of proteins (foods such as lentils, turkey or egg.)

Adequate serotonin levels can help improve mood and increase sleep, while reducing cravings and aggression. Dopamine can also help improve mood and increase alertness, cognition and problem-solving skills. Sounds pretty neat, but how do we ensure we have the right balance of these brain chemicals or neurotransmitters? 

As mentioned, these brain chemicals are made of amino acids found in protein-based foods. Dopamine is made from the amino acids tyrosine and phenylalanine found in eggs, meats, almonds, fish, legumes and more. Serotonin is made from the amino acid tryptophan found in eggs, milk, yogurt, bananas and meat. These amino acids are found in variety of foods, but if you follow a vegetarian diet or simply have a low intake of protein through the day, consider the potential impact of this on your brain.

It is important to understand that at this time there is very limited and conflicting research on the direct effect of dietary amino acids on depression, anxiety and overall mood. Depletion of these amino acids does appear to worsen symptoms of depression, but not much can be said with certainty. However, protein is a crucial element of our diet, responsible for many functions in our body. Think of this as another important reason to ensure you consume enough protein in your day, especially if mental health is a health goal you are working on.

Carbohydrates also play a key role in production of serotonin. Sugar from the carbohydrates allows the amino acid tryptophan to enter the brain and convert to serotonin. Consequently, low-carb diets may affect mood and may be particularly unsuitable for those battling depression, anxiety, substance abuse or other psychological conditions. It is recommended to consume low glycemic index carbohydrates for mental wellness as well as your general health. Low glycemic index refers to carbs that convert to sugar slowly and offer lots of fibre. Examples of these include fruits and vegetables, sweet potatoes, brown rice, legumes, oatmeal and much more. These types of carbs will provide a long-lasting and beneficial affect on the brain chemistry, mood and energy levels, whereas foods high in simple sugars provide a very short-term relief likely followed by more cravings and fatigue.

Your brain is the organ with the highest fat content. Consequently, fat also plays a role in brain function. A significant portion of the brain’s structure is made of fat supplied by our diet, as the body cannot make it on its own. These important fats are polyunsaturated fats, also known as the omega-3 and omega-6 fatty acids. It is important to consume the right balance of these fats. While omega-6 is easier to obtain as it is found in abundance in nuts, seeds, corn oil, sunflower oil and many more, the omega-3 fatty acid is more of a challenge. Omega-3 fatty acid, in its most active form, is found in fatty fish such as salmon and sardines, but it is not found in any other foods, hence the standard recommendation to consume fatty fish 1-2 times per week. There are also plant source of omega-3 fats, that can convert to the active form, albeit less efficiently, and are found in flax seeds and flax oil, soy products such as edamame beans and walnuts. These fatty acids help maintain the integrity of the brain structure and function. Experimental studies have shown that omega 3 may help combat depression and reduce inflammation, but much more research is needed. 

Lastly, in addition to macronutrients (proteins, fats and carbohydrates), micronutrient intake is just as important. B vitamins, including folic, acid, B6 and B12 are also essential to the production of serotonin and dopamine. Vitamin and mineral deficiencies, such as iron, folic acid, B6 and B12 can mimic or exacerbate mental health problems and symptoms such as depression, fatigue, poor attention and altered sleep. The effect of different vitamin and mineral deficiencies on mental health will be discussed separately as it is a rich topic in itself.

This is a lot of information, but we can simplify to put it into practice: 

1. Ensure you have adequate intake of protein through the day from a variety of sources. This will help you consume all the necessary amino acids, iron and B vitamins needed for production of dopamine and serotonin. 

2. Make sure your diet incorporates essential fatty acids, omega-3 and omega-6, with special attention to omega 3-fatty acids as foods rich in these are limited. Make fish part of your weekly menu or explore plant sources of omega 3, such as walnuts, tofu and flax oil. 

3. Lastly, ensure that you are consuming the amount of carbohydrate that is right for you. If suffering depression or anxiety steer clear of carb-free or extremely low-card diets. Both, type and amount (insufficient or excessive) of carbs can affect your brain function, the rest of your body and consequently your mood.

If you have additional questions or require assistance with your dietary intake, please discuss with your primary care provider to see if a referral to a registered dietitian may help you. 


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4. aan het Rot M, Moskowitz DS, Pinard G, et al. Social behaviour and mood in everyday life: effects of tryptophan in quarrelsome individuals. J Psychiatry Neurosci 2006; 31:253-62.