Brain Food - Nutrition for Mental Health

By Georgina Duncan (BHSc.Naturopathy).


Anxiety can be the result of many factors, both physical and psychological. For example, stimulants such as caffeine can be a trigger but so can periods of long term stress, and elevations in blood lactic acid levels (the final product of the breakdown of blood sugar when there is a lack of oxygen). Caffeine, sugar, alcohol and food allergies can trigger anxiety but so can deficiencies in B vitamin’s, magnesium and calcium. Eating foods that are rich in these nutrients can help support neurotransmitter synthesis, modulate hormone production and action, and help reduce symptoms of anxiety.


Like anxiety, a number of physical and psychological factors can be found at play in depression. The dominant physiological theory is known as the ‘monoamine hypothesis’, in which there is an imbalance of the monoamine neurotransmitters such as serotonin, epinephrine and nor-epinephrine. Nutrient deficiencies, drug use (including prescription), alcohol, caffeine, nicotine, hypoglycaemia, hypo or hyperthyroidism and food allergies can all impact on these neurotransmitters. A long term deficiency in any nutrient or mineral will have adverse effects, but with a specific focus on the neurotransmitters commonly found in mood disorders, increasing B vitamins (especially B6, B9 and B12) and omega 3 fatty acids is a necessity.

The brain requires a constant amount of blood sugar to function. Studies have shown hypoglycaemia (low blood sugar) to be common in those with depression and anxiety, and simply switching from refined carbohydrates to a whole grain, whole food based diet with suitable amounts of fats and proteins, as well as eating at regular times can significantly improve and stabilise mood. Food allergies are another common, yet often overlooked factor in mental health, and removing triggers can also yield results.


IBS is characterised by a combination of the following: abdominal discomfort, altered bowel function, constipation, diarrhoea, hyper-secretion of colonic mucous, excessive flatulence, nausea, loss of appetite and varying degrees of anxiety and depression. Four main causes of IBS are stress, low dietary fibre, food allergies and high intakes of sugar.

What is now commonly referred to as the gut-brain axis is one reason why so many gut-based issues also present with signs and symptoms that relate back to mental health. Addressing the cause of IBS, restoring the gut lining and microflora, replenishing nutrient deficiencies as a result of poor absorption and removing triggers will inadvertently help reduce the co-morbities of anxiety and depression.


Typical symptoms of PMS include acne, low energy levels, tension, irritability, anxiety, depression, mood swings, headaches, low sex drive, insomnia, back pain, cramping and bloating.

A common finding for PMS is that estrogen levels are excessively elevated and progesterone is out of balance accordingly.

A predominantly vegetarian based diet with high amounts of fibre rich plant food, has shown to be effective in bringing down estrogen levels; studies have shown that vegetarian women excrete 2-3 times more estrogen in their stools than omnivores. The effect of caffeine is also very significant in women who experience changes their psychology around menses, as it can impact negatively in the brain receptors. Foods high in Vitamin B6 help metabolize and excrete estrogen, as do cruciferous vegetables such as broccoli, cauliflower and kale (cooked), while magnesium rich foods can help stabilise hormones.


Alcohol takes many of these essential nutrients mentioned and uses them in its metabolization and elimination. Keep this in mind when drinking – you need to ensure you are having more than enough nutrients to avoid dipping below the threshold. Never replace food with alcohol, and if you are drinking, or drink regularly, your food needs to be nutrient dense.


It is estimated that only 2% of pesticides actually serve their purpose, while the other 98% are absorbed into the air, water, soil and food supply – and inevitably, into us. While some pesticides are now banned, it doesn’t mean that they are gone. For example, DDT, has been banned for almost 30 years, but because of its long half life, it is still being found in the soil and in root vegetables. Furthermore, the amount of different types of pesticides and fungicides has drastically increased.

For example, more than 110 different pesticides are used on apples.

Even if such products are deemed ‘safe’, the sheer amount that can end up being ingested can cause havoc on the gut microflora, add a heavy burden to the liver and cause mental disturbances through either the gut brain axis, the recycling of toxic metabolites through an over burdened liver, increasing inflammation by damaging cell membranes, or acting on neurotransmitters.

Eating organic foods reduces your exposure to not only pesticides, but also heavy metals such as lead and mercury (whose detrimental effects to the brain have been well established), and solvents which damage immune cells. Furthermore, organic grown foods often have a higher nutrient profile. A review of 34 studies comparing organic to non organic produce, found organic food had a higher protein quality, higher levels of vitamin C, and 5-20% higher minerals such as magnesium, zinc and iron, as well as having higher levels of antioxidants.



Kelp & other seaweeds, wheat bran & germ, almonds, cashews, buckwheat, brazil nuts, millet, pecans, walnuts, rye, tofu, soybeans, brown rice, collard greens, avocado & cacao.


Red meat, pulses, chicken, oysters, fish, nuts, seeds (especially pumpkin) and ginger root.


B1 – meat, fish, chicken, whole grains, peas, beans, milk

B2 – organ meats, yeast extracts and milk

B3 -  meat, fish, poultry, whole-grains

B5 – chicken, beef, potatoes, oats, egg yolks, broccoli, whole-grains, milk, leafy greens, royal jelly

B6 – whole-grains, legumes, eggs, yeast extracts, sunflower seeds, wheat germ, soybeans, walnuts, lentils, buckwheat, black eyed peas, navy beans, brown rice, hazelnut

B9 – Black eyed peas, rice germ, soy flour & beans, wheat germ, wheat bran, kidney beans, mung beans, navy beans, chickpeas, asparagus, lentils, walnuts, spinach

B12 –Oysters, sardines, trout, salmon, tuna, lamb, eggs, beef, edam cheese, swiss cheese, haddock, cheddar cheese, nutritional yeast flakes


Seaweeds, cheddar cheese, leafy greens , almonds, parsley, dandelion greens, brazil nuts, watercress, goats milk, tofu, sunflower seeds, buckwheat, sesame seeds or tahini.


Salmon, mackerel, herring, halibut, oysters, anchovies, flaxseeds (linseeds), ground flaxseed oil, walnuts, chia seeds, soy beans, hemp seeds.

Further reading:

Clinical Naturopathic Medicine, by L. Hechtman

The Encyclopedia of Healing Foods, by M. Murray & J. Pizzorno

Georgina DuncanComment