Food-mood-sleep connection

The gut and the brain are involved in a long distance, but extremely close relationship. They are so intimately linked, and we are only just beginning to discover just how deep that relationship goes. So it’s no surprise to learn that what we eat can have a huge impact on how we feel, our emotions, moods and sleep. 

We all know about, and probably have felt, that gut instinct. Or a feeling in the pit of our stomach. Or going with our gut. It’s no coincidence that these idioms relate our feelings to our gut – and now we realise that this connection is more true and real than we ever knew.


The gut, and the food we feed it, will influence our brain. Primarily this is due to the fact that it produces many neurotransmitters (brain chemicals) which then get sent to the brain. This connection happens via the vagus nerve which is a two way highway between gut and brain.

The bacteria in our gut microbiome are responsible for producing around 90% of our serotonin for example. Serotonin is our happy hormone and is often found to be imbalanced with people suffering depression or anxiety. Our gut microbiome also produces around 50% of our dopamine – another happy hormone. 

So when we realise that it’s our gut rather than our brain that produces so many of our neurotransmitters, we begin to realise that we can alter our brain chemistry quite literally by nourishing our gut bacteria, and in doing so, we can influence our mood with our food.

So how do we feed our gut microbiome? Well the good bacteria like to eat fibre – so increasing our intake of whole fruits and vegetables is a good start. Eating the whole fruit rather than juicing them means we get the full benefits of the fibre. We can also repopulate good bacteria into the gut by eating fermented foods such as kefir, sauerkraut and kimchi, even some natural full fat Greek yoghurt. These are abundant in beneficial bacteria in a truly absorbable form. 

If necessary then it may be helpful to use targeted probiotic supplements, a market which has seen exponential growth in recent years. Psychobiotics are the new probiotics! This is a term for using probiotics to improve our mental health.

Another way to keep our gut bacteria happy is to manage our stress levels. The stress hormone cortisol has been shown to encourage the growth of bad bacteria and inhibit the growth of good bacteria. Not good news for keeping this delicate ecosystem of bacteria in balance. So finding ways to unwind is really important to shift us out of fight or flight. This could be walks in nature, yoga, deep breathing, meditation, even just a phone call to a friend. 

Physical stresses on the body will also affect our mood, and these include a high sugar diet, highly processed foods, sweeteners, stimulants like alcohol, underlying yeast or bacterial infections, as well as medications such as antibiotics and antacids. They all have a negative effect on the balance of the gut microbiome and therefore on our mood. So the state of our gut clearly influences our state of mind.

As with all good relationships – this is a two way street.

The gut brain connection working in the opposite direction is most easily demonstrated by that familiar feeling of butterflies in our tummy, perhaps before an important meeting or exam. This shows that a thought, feeling or emotion of anxiety or anticipation actually has a direct physical effect on our gut. Our thoughts and feelings are so powerful that they can actually make us physically feel (or even be) sick.

We all have a relationship with food and the ideal is for this to be a balanced relationship as much as possible. Often we eat our feelings and look to food to reward ourselves, punish ourselves, cheer ourselves up, or maybe out of boredom, anxiety and loneliness – particularly relevant during these winter months where we are still restricted in terms of social contact and are working from home in close proximity to the fridge!

This can become something of a vicious cycle, where we make poor food choices because we are tired, stressed, lonely and bored, and then because we have made those poor food choices, our body responds by craving those foods. So the food we eat influences our mood, and the mood we are in influences our food choices. 

Breaking this vicious cycle is really important and once we recognise this link, it’s a first step. We also need to consider that balancing our blood sugar hormones will go a long way to breaking the cycle, as part of a wider treatment plan if necessary such as working on exercise, emotional healing, stress management and seeking professional help.


The best way to balance our blood sugar and keep it stable throughout the day and flatten that curve (much like the current pandemic!) of sugar highs and sugar crashes, is to include the three main food groups at every meal. So we need good quality protein (meat, fish, eggs, dairy, quinoa and other pulses) alongside some slow releasing carbohydrates such as vegetables, salads, sweet potatoes, and some good healthy fats. 

Yes fats! We absolutely need good fats in our diet – and when we’re talking about mood foods – fats are essential – since the brain is made up of around 60% fat! So we need to feed it good fats to keep it happy and functioning optimally. Some examples here would be avocado, nuts, seeds, fatty fish like salmon, mackerel, herring, sardines. These all contain omega 3 which is an essential fatty acid (so called because our body needs it but can’t make it, so we have to get it from our diet). 

This is not to say that food can heal all mental health issues alone, nor is it to downplay the role that medications have. Rather its about understating the role of food in our mental health and using food as part of a wider treatment plan.


The gut bacteria also communicate with our brain to determine our sleep patterns. We need good levels of melatonin at night (our sleepy hormone), which once again is produced in the gut as well as the brain. Eating meals and snacking late in the evening, stress (cortisol), blue light from our phones and screens, certain medications, and not enough sunlight during the day are all factors which can interfere with our production of melatonin. So it’s important to get some fresh air if possible each day – particularly in the morning in order to keep our circadian rhythm in check.

Having consistent bedtimes is also helpful, as too many late nights and changes in our body clock can alter both the composition and the behaviour of our gut bacteria. This then affects our mood and our sleep.

Poor sleep is associated with poor diet, and so if we are having sleeping problems, especially in the current uncertain times, it may be wise to avoid foods that will disrupt sleep and play havoc with our natural body clock. For example stimulants such as caffeine, alcohol, energy drinks and sugar. Also having meals late at night can disrupt sleep. Your body wants to be doing its healing, repairing, renewing and detoxing at night – not to be digesting food which also slows down melatonin production!

Foods that are conducive to sleep are omega fatty acids – so the good fats mentioned above, as well as foods that contain melatonin such as eggs, fish, milk, rice, grains such as barley and oats, vegetables such as broccoli, tomatoes and cucumber, and pistachios, walnuts, sunflower seeds and flaxseeds and pumpkin seeds which contain tryptophan – the precursor to melatonin. 

Cherry juice has also been found to improve sleep as cherries are a rich source of polyphenols and increase tryptophan availability. Similarly chamomile tea has long been associated with a calming good night’s sleep – and for good reason. It has sedative effects thanks to a flavanoid called apigenin which uses the same receptors in the brain as Valium!

There are many minerals that are associated with low mood, such as a deficiency in iron, zinc, selenium and magnesium. Try adding some Epson salts (magnesium sulfate) in the bath at night, or using a magnesium body butter, to increase magnesium levels in an absorbable way via the skin, bypassing the digestive system. Similarly vitamins such as all the B vitamins particularly B9 folate and vitamin D deficiencies can be linked to depression. 

There are so many supplements and probiotics on the market it can become a minefield as they are not all made equal! Many contain synthetic artificial nutrients and are packed with fillers and additives, whereas others are more food based and natural. Best advice where possible is to get all your vitamins and minerals from food, but where this isn’t possible then seek advice from a trained nutrition professional who can advise on the right supplements for you.


Above all it’s a good idea to get a varied, Mediterranean style diet that is rich in fibre and variety of plant foods and good quality protein with good fats added in too, as this will all feed your good gut bacteria and thus contribute to a good immunity, mood and hormone balance. So eating a variety of preferably organic vegetables and fruits for maximum polyphenols and antioxidants, upping our green leafy vegetables for folate and iron, including protein at every meal such as grass fed meat and eggs, wild caught fish, and good quality fats too, will all be valuable in our mission to eat good foods for good moods. 

Even herbs and spices will play a role. Herbal teas like chamomile and lavender have proven effective at lowering levels of anxiety and improving sleep, whereas spices like turmeric, saffron and oregano can be used liberally in cooking to uplift mood due to their abundant antioxidant properties.

Very proud and honoured to have this article featured in the Health Supplement of the Jewish Chronicle newspaper – see below: