Mental health, specifically depression, has become more talked about in recent years, although there is still lots we don’t know or understand. Mental health is a very complicated subject and is linked to genetics, psychological exogenous and biochemical endogenous imbalances created through millions of years of evolution.

What makes a person happy?

This is a question that people have been asking for millennia! Is it related to health, wealth, relationships, a sense of purpose or a subjective expectation? One thing is clear, we are all different and our life expectations are different. Yet millions of people suffer with poor mental health in the UK. Older people seem to suffer more through poor nutrition and loss of loved ones and women more than men.

Evidence suggests that there are many types of depression and triggers can be both external psychological and internal biological. Depression has been shown to have a genetic component, and like genetics, environment also tends to run in families (for example, external factors such as an abusive upbringing or financial problems can be a factor). Stress can disrupt our biology to such an extent that it can affect every system in the body, as can oxidative stress, which creates a build-up of free radicals that damage cells, proteins and DNA and are both potential causes for depression. Chronic sickness and poor nutrition leading to a lack of essential nutrients can increase feelings of depression. Hormone imbalances such as an underactive thyroid or an increase in glucocorticoids that are released during times of stress are also thought to cause depression. An increased prevalence of depression is seen between the menarche and menopause, which implicates oestrogen or progesterone as a possible cause. The hormonal changes through the menstrual cycle can affect many women, as too can the reduction of oestrogen during menopause. Blood sugar imbalance, gut dysbiosis, heavy metals, environmental pollution, bacterial and yeast overgrowth, food intolerances, recreational drug use and even extended use of calcium supplements are linked and possible causes or contributors for depression. The most popular reason touted in the cause of depression, however, is an imbalance of the neurotransmitters.

Electrical nerve impulses sweep across our neurones. The impulse starts at the dendrites and travels along the cell along the body (axon) to the axon terminals where it releases a chemical messenger known as neurotransmitters (serotonin, adrenalin, dopamine) that travel across the space between cells (synapses) binding to the specialised receptors on the adjacent cell dendrites. Interestingly the excess neurotransmitters are then either reabsorbed back into the axon terminal or they are degraded in the synapse by a process called deamination by an enzyme called monoamine oxidase where they are flushed into the cerebrospinal fluid, then into the blood and ultimately removed in the urine. Different neurotransmitters send different messages, which are either excitatory or inhibitory and create different functions, pancreatic regulation, is one example. This is fine, however if the proper removal processes by the two above fails than there will be an increase in the neurotransmitter concentration in the synapse. This will create a stronger and prolonged action, whatever that function was.

What is serotonin and why is it important?

When talking about the subject of depression the hormone and neurotransmitter serotonin will inevitably be mentioned. Serotonin is referred to as the brains own mood elevating and tranquilising drug. It is made in the body and brain from an amino acid 5-Hydroxy Tryptophan (5-HTP), which is made from an amino acid called tryptophan. Tryptophan can be found in many protein rich foods such as meat, fish, beans and eggs. Consuming foods that are high in tryptophan along with foods high in complex carbohydrates will help enhance the absorption of tryptophan. Carbohydrates may also boost serotonin activity in the brain. Sources of complex carbohydrates are brown rice, potatoes, pasta, wheat, wholegrain cereal, wholemeal breads and lentils.

It is suggested that one cause for depression is the abnormal concentrations of the neurotransmitter’s adrenalin, dopamine and serotonin. Many anti-depressant drugs manipulate these hormones/neurotransmitters in different ways. Some prevent the reabsorption of these neurotransmitters by the axon terminal allowing them to circulate for longer, and eventually being taken up by the adjacent cell receptors. Other medication will block the degrading action of monoamine allowing more neurotransmitters to survive. There are different theories as to why this happens, is it because the individual is not producing the neurotransmitters via a malfunctioning feedback system? Or are they producing too many and the neurones have down-regulated the receptors to those particular neurotransmitters (much like insulin or leptin resistance)?

Chronic stress and, more accurately, the releases of adrenocorticotropic release hormone, which via a chain reaction eventually produces cortisol, affect the seat of emotion, the hypothalamus and inevitably promote depression.

Thyroid disfunction is massively linked with depression. Low thyroid output increases the activity of a2-adrenergenic receptors, which subsequently reduces the mood elevating neurotransmitter noradrenalin. Low thyroid output will also reduce serotonin binding to receptors on the adjacent dendrites further increasing feelings of depression. As if that wasn’t enough, poor thyroid function also increases the activity of the enzyme monoamine oxidase, reducing noradrenalin and its mood elevating benefits.

These are just a few theories behind the reasons for depression. From this we can see that nutrition can help a great deal, however in complicated mental health conditions nutrition alone is unlikely to be enough.

What is nutritional psychiatry and can you eat yourself happy?

Nutritional psychiatry utilises food and supplements as an alternative to medication in the treatment of mental health.

There have been a number of studies to show that a good diet will help to improve mental health. No single nutrient is a ‘panacea’ to help with mental health conditions. However, eating a clean diet that balances blood sugar, helps the liver to remove toxins, balances hormones, up-regulates thyroid function and helps to increase energy levels and other positive aesthetic changes will subsequently improve mood. Removing refined foods, processed foods, additives, alcohol and caffeine from the diet will also help many other conditions as well as mental health. Other important factors that will affect mental health are lifestyle, exercise, sleep and stress levels.

Which foods have been shown to be helpful for mental health?

Omega-3 and 6 essential fats – these have been shown to be beneficial for mental health, although the mechanisms for this are still not clear. Surveys have shown that the more fish a country eats the lower their incidence of depression. A type of omega-3 fat called EPA seems to be the most potent natural anti-depressant. Essential fatty acids support stress hormones and assist in balancing blood sugars, which will also support mood. Omega-3 fats produce anti-inflammatory prostaglandins, this may be significant as in many cases people with depression have increased inflammatory markers. The richest dietary source of omega-3 fats is from fish, specifically carnivorous cold-water fish, such as salmon, mackerel and herring. It is also found in nuts, seeds, flaxseeds, linseeds and flaxseed oil.

Fresh fruit and vegetables, whole grains and lentils - these foods are high in fibre, which aids liver function and feeds the important probiotics and high in antioxidants which support the immune system, liver and help to mop-up free radicals. These foods also have a low glycaemic index, which helps to control blood sugar (there is a direct link between mood and blood sugar balance). All carbohydrate foods are broken down into glucose and your brain runs on glucose. The more uneven your blood sugar supply the more uneven your mood.

Chromium - is vital for keeping blood sugar levels stable because insulin, which clears glucose from the blood, can't work properly without it. Good sources of chromium include beef, liver, eggs, chicken, oysters, wheat germ, green peppers, apples, bananas and spinach.

B vitamins – these play a major role in maintaining proper brain chemistry, proper nerve function in the brain as well as energy production. Deficiencies are common in those with depression, particularly folic acid and vitamin B6. A lack of vitamin B may also cause fatigue. B’s, specifically B12 and B9, are needed to synthesise dopamine from tyrosine. Low levels of the brain chemical dopamine have been linked to feelings of depression. Foods rich in the amino acid tyrosine are therefore thought to help with symptoms of depression. Good sources are dark green leafy vegetables (spinach and broccoli) and whole grains (oats, brown rice, chickpeas). Foods rich in tyrosine are almonds, avocados, bananas, lima beans and pumpkin seeds.

Magnesium - is a mineral that may ease symptoms of depression by acting as a muscle relaxant. Along with other salts it also plays a role in proper nerve function. It is also needed along with some B vitamins for the production of dopamine. Good sources of magnesium include spinach, pumpkin seeds, oysters, sunflower seeds, brazil nuts, amaranth, buckwheat, avocados, quinoa, almonds and barley.

Zinc – a zinc deficiency may affect both depression and appetite. Zinc is necessary for the production of serotonin and also for taste. A lot of zinc is passes from the mother to the foetus days before birth, so for a new mother eating zinc rich foods is advised. Zinc can be found in nuts, seeds, beans and lentils and wholegrains. Other good sources are oysters, alpha sprouts, turkey, brown rice and asparagus.

It seems our gut flora helps to convert the amino acid tryptophan to serotonin and a lack of numbers and diversity can contribute to depression. Eating a diet rich in fibre and fermented foods (sauerkraut, kimchi and kefir) are essential to increase gut flora. It may also be worth supplementing gut flora with probiotics. As already mentioned, many people with depression have increased inflammatory markers and gut microbes have been shown to help in the regulation of inflammation.

Foods that have been shown to be detrimental to mental health and should be avoided or consumed in moderation

Alcohol - lowers serotonin levels (the feel-good hormone) and B vitamins needed for proper nerve function in the brain as well as energy production.

Refined foods - those that contain high amounts of sugar can create a rapid blood sugar rise and subsequently a large blood sugar drop that greatly affects a person’s mood, as well as depleting the essential B vitamins. High sugar diets also decrease the number and diversity of gut flora.

Caffeine - can also affect blood sugar, disrupt sleep (which is essential for good mental health) and it can deplete those important B vitamins and chromium, which is an important mineral for blood sugar balance.

Saturated fat – it’s important to try to reduce your intake of saturated fat as it will compete with and reduce the absorption of the beneficial polyunsaturated fats omega 3 and 6.

Food intolerances – it’s important to consider if there are any possible food intolerances, which may prevent nutrient absorption. Wheat, dairy and eggs are common allergens in some people. These affect digestion and reduce uptake of essential nutrients needed for proper body function impacting on a whole host of biological systems inevitably affecting mood. For example, selenium, zinc and iodine are needed for proper thyroid function. An under-active thyroid may contribute to depression and anxiety (thyroxine is needed by all cells and especially the brain).

Restrictive diets - it is worth noting that restrictive low calorie and low carbohydrate diets will lower overall nutrient and fibre intake as well as potentially slow thyroid output and impact both metabolism and energy levels, which in turn can impact depression.

Other factors that have been shown to benefit mental health

Numerous studies over the years have shown that regular exercise is an essential element to any protocol dealing with depression; the physiological and psycological benefits are huge and far-reaching not least from the feel-good endorphins (natural antidepressants released when we exercise). Exercise will also help with sleep (lack of sleep is a massive contributor to mood fluctuations and a good night sleep is essential for immune function). There are lots of new studies linking sleep and mental health and that getting enough sleep is important for good mental health.

Natural sunlight helps to supress the hormone melatonin. Melatonin, produced by the pineal gland, is an essential hormone and powerful antioxidant, however, it also makes us feel tired and depressed, especially in the winter. Getting enough exposure to sunlight can help us to feel more energised, which can be helpful in depression.

I would like to reiterate that I wouldn’t recommend supplementing any of the nutrients highlighted above individually (with the exception of essential fats and probiotics) as they all work synergistically with each other. A healthy diet will contain all the nutrients needed to support all the body systems and subsequently mental health Good nutrition can definitely have a positive impact on mental health. However, it is important to remember exercise, sun exposure, a good network of friends and reducing possible exacerbators like alcohol, caffeine and recreational drugs will also have an impact.

This article has
been written by
Terry Fairclough