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As it was Mental Health Awareness week last week, I thought I would write about how food can play a role in mental health conditions, such as anxiety and depression – providing a functional focus to show how a holistic view is needed when supporting clients who suffer with these conditions.

Many of us may have down days or a pre-disposition to anxiety or nervousness (the perennial worrier) but it is when these states begin to affect our day to day life that help is often sought.  The conventional approach is usually to prescribe a SSRI (selective serotonin uptake reinhibitor) for depression and a benzodiazpine based drug (or SRRI) for anxiety.   The use of these medications is rapidly on the rise – they do not always work, they can have severe withdrawal symptoms, associated with numerous side effects and patients are often simply left on them long term.

Depression and anxiety are typically considered an imbalance in the brain’s neurotransmitters.  Neurotransmitters are molecules that carry signals between neurons via nerve junctions (synapses).   So in order for the neurotransmitters to do their job properly, the receptors that pick up the neurotransmitters must also be working.  Serotonin typically dominates the conversation where depression is concerned but their are others which can be classified as to whether they have a calming or excitatory role.  The primary ones are:


  • GABA –   or gamma-aminobutyric acid, is not only a neurotransmitter but also an amino acid.  It decreases a neuron’s excitatory potential and is critical for relaxation, improving memory and mood.  Benziodiazepines interact with GABA receptors.  Interestingly, glutamate that GABA is made from is typically high in OCD patients  – B6 and zinc are needed to convert glutamate to GABA and there are well researched genetic polyphmorphisms impacting individual variability of this conversion.
  • Serotonin – often known as the ‘happy hormone’.   It is estimated that anywhere from 70-90% is made in the gut.  Serotonin is made from tryptophan and converted onto melatonin, both crucial for various stages of sleep.


  • Dopamine – dopamine is a powerful neurotransmitter which is involved in pleasure and the reward centre – low dopamine can make an individual more likely to consume addictive substances such as certain foods and drink.  It can compete with serotonin for uptake at the receptors, it is upregulated by cortisol and needs adequate vitamin D and B6 for production.
  • Acetycholine – plays an important role in memory and cognition.  Thought to play a role in Alzheimers.
  • Other excitatory neurotransmitters are: adrenaline, nor-adrenaline, histamine, glutamate and phenethylamine (PEA)

The life-cycle of a neurotransmitter involves various stages – understanding this helps to understand where things can go wrong:

  1. It must be synthesised ie you need the raw materials – relevant protein for the neurotransmitter itself but also the enzymes and co-factors (your minerals and vitamins).  Environmental stimuli also plays a role here – eg if you are constantly under stress, your body thinks its needs to make more excitotory neurotransmitters to escape the tiger (when actually you are sitting at your desk).
  2. It must signal to neurons the correct message –  thus it needs receptors that work.  Receptor function is also under genetic control.
  3. It must be transported – it must be removed from the synapse and taken back up into storage (this is where SSRI’s come in by inhibiting the reuptake of serotonin and allowing it to stimulate the neuron for longer).
  4. Neurotransmitters must then be broken down and their metabolites (breakdown products) removed (liver and gall bladder function, GI issues can all impact this).


How Nutrition can help support Depression and Anxiety

Genetics can play a significant role in all of these steps (1) and working out which pathways are not working well in you can involve looking closely at family history, your own history and symptoms, accompanied, if possible, with tests to help narrow the focus.   Genetics can impact the ability to make neurotransmitters, the ability to break them down and receptor function.  However, just because you have a genetic predisposition does not mean that this genetic trait will be expressed.  There is a saying, ‘Genetics load the gun, diet and lifestyle pull the trigger’.  Testing neurotransmitters, neurotransmitter metabolites and genetic testing are all options *

So what causes an imbalance in those who are genetically predisposed, what pulls the trigger?

There is a growing body of evidence that inflammation  is driving these types of conditions (2).   What drives inflammation?  Underlying chronic health conditions such as undetected pathogens, yeast overgrowth, nutrient deficiencies, food intolerances and allergies, a diet high in processed and sugary foods, a diet low in anti-inflammatory essential fatty acids, a build up of toxins, lack of sleep and, in athletes, over-training.  There are more but these are some common ones.

One of the pathways that can be altered if inflammation is chronically elevated, can result in a redirection of tryptophan away from the production serotonin to something called kynurenic acid.  Kynurenic acid is neuro-toxic and excitatory.   Another potential impact is via chronically elevated stress levels can lead to a depletion in certain B vitamins and magnesium, all required for not only optimal neurotransmitter function (synthesis and breakdown) but can lead to a build up in inflammatory molecules such as homocysteine in genetically susceptible individuals (or in fact anyone!).  These can all be tested to find out what is going on inside you.

It has also been shown that neuro-inflammation can slow down conduction of the messages between neurons and impact the receptor sites themselves.  So even if you have enough of the neurotransmitters, they cannot do their job.  A more recent line of thinking, involves a set of cells in the brain called glial cells which are part of the brain’s immune system and when these cells are over-activated, they dont always switch off when they should and can cause chronic brain inflammation and depression.

Potential Causes of inflammation:

  1. Consider pathogens, parasites, candida overgrowth as an underlying root cause and all can result in increased inflammation.  Systemic candida overgrowth is strongly associated with anxiety.
  2. Diet – assess your diet.  Processed foods high in processed flour, sugar, chemicals and preservatives whilst being low in omega 3’s and fermentable fibre can result in an upregulated inflammatory response.
  3. Gluten (could be covered under diet but worthy of its own mention) – I don’t believe every one should have to avoid gluten, but there is increasing evidence that it plays a significant role in the development of neurological disease in susceptible individuals (3). Gluten has been shown to up-regulate a certain protein involved in regulating the permeability of the gut lining and excess consumption can result in what is commonly known as ‘leaky gut’.  ‘Leaky gut’, or increased intestinal permeability, allows unwanted allergens to be able to cross from the gut into systemic circulation up-regulating the immune system.   Please note that being tested for celiac disease and receiving a negative result does NOT rule out an auto-immune reaction to gluten.
  4. Being overweight – fat cells are endocrine organs themselves and produce their own inflammatory molecules called adipokines – thus providing potential explanation for the strong association between obesity and depression (4).
  5. Poor Gut Health –  a ‘leaky gut’ or when the gut lining is damage and more permeable, molecules that should have stayed in the gut to be excreted are able to get through into systemic circulation which can cause an inflammatory response.  The gut is also home to billions of bacteria known as our gut microbiome and a disruption in this balance, say through antibiotic use, can result in altered serotonin production.
  6. Underlying chronic health conditions such as hypothyroidism. Hypothyroidism is strongly associated with depression (5) and can not always be detected by testing TSH alone as is typically done by the GP.  A full thyroid panel should be run.
  7. Sub-optimal Liver Function – poor liver function can lead to increased inflammation and sub-optimal breakdown of neurotransmitters and their metabolites.

How Nutrition can support Depression and Anxiety

What can you do?

Diet is sometimes the hardest place to start when you are feeling low.   Take it step by step and don’t be hard on yourself if you have a bad day.  The basic principles you need to follow to begin reducing inflammation are:

  • Remove anything processed and reduce overall sugar consumption.  The easiest way to do this is just do not have them in the house.  If they are there now, just throw them out.  It is rubbish – don’t treat your body like a human rubbish bin.
  • Increase your intake dietary intake of good fats such as oily fish, hemp oil, extra virgin oil, avocados, coconut oil, nuts and seeds.
  • Increase significantly the amount of green leafy vegetables you eat and brassicas can be particularly important for those who suffer from long-term anxiety where genetic SNPs such as COMT and MTHFR may be involved (click HERE for more information).
  • Include plenty of brightly coloured vegetables and plenty of berries for their anti-oxidant content to combat inflammation.
  • Buy organic where ever possible due to the high amount of pesticides and chemicals used in the food chain
  • Cook with anti-inflammatory herbs such as turmeric and oregano.
  • Include plenty of foods that are high in B vitamins, magnesium and zinc such as seeds, nuts, shellfish
  • Omega 3 supplementation – even if you eat oily fish, often therapeutic levels are needed to help reduce chronic inflammation.  Seek  advise for from a suitably qualified practitioner
  • Vitamin D – get your levels checked!  Either go to the GP, ask your Nutritionist to arrange it or follow this link.  Optimal ranges of vitamin D are not just above deficiency! Read more here about optimal levels.
  • Lifestyle changes to reduce stress such as meditation and yoga.  Get outside each day and get fresh air.
  • If you suspect any other underlying imbalances/conditions that may be at the root cause of your condition, seek help and work with a suitably qualified functional therapist who can help you work out what is going on.

* Testing of neurotransmitters and metabolites can done via urine and has been shown to have scientific validity (1 , 2 ).

If you would like to book a call with Katherine to discuss how she can help click here or  fill in the form below.