What causes low mood?
Most of us can point to one or more reasons
to explain a change in our mood. Perhaps we had a poor night’s sleep
, our hormones are out of balance, we’ve not been exercising or we miss seeing friends. It could be down to stress, genetics
or even our environment. These are all valid explanations, but a growing body of evidence
supports another factor – and that is the food we eat.
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How does food influence my mental well-being?
Food, by its very nature, is a powerful reward – eating delicious meals triggers the reward and pleasure centres in the brain, which in response release dopamine. This brain chemical manages our sense of satisfaction and without it we lose interest, lack motivation and feel lacklustre.
Without doubt some of the pleasure we get from eating certain foods, like chocolate and cake, comes from our cultural learning – we grow up associating these foods with special occasions and rewards. However, the role of food goes beyond being just a ‘comfort’, our mental well-being and the food we eat appear to be intimately entwined. Read on to discover what the science tells us.
What does the research on food and mood say?
Over the last decade, our understanding of the complex relationship we have with food has grown exponentially. Recent studies
reveal how intricately connected our gut, brain, nervous system and behaviour are. This connection is thought to be multi-modal and operates via physical, chemical and even microbial means.
Our gut and brain are physically linked by millions of nerves, the most important of which is the vagus nerve
. Chemicals including serotonin, the smile-inducing feel-good brain chemical, are produced in both the brain and the gut and communicates via the nervous system, whilst beneficial gut microbes
play an important regulatory role. These trillions of microbes don’t stop there, they influence our emotional well-being by producing neuroactive substances, including short chain fatty acids
(SCFA), which help lift dark moods.
This intricate network of activity relies heavily on the food we eat, with key nutrients like the omega-3 fatty acids
, protein, vitamin D, the B complex of vitamins
, iron and fibre all playing a part in helping to keep us positive and happy.
How can I support my mood with food?
Start by making these 5 simple changes to what and how you eat:
1. Eat a minimum of 5-a-day
Studies support that when we eat more fruit and vegetables, we experience a positive effect
on our mental health. By including a variety of colourful veg, we may even help lower levels of depression
. The exact mechanism behind this isn’t fully understood, but it may be because fresh produce is packed with protective antioxidants which help to keep the brain in good health. Certain fruit and vegetables may be even more helpful. Take bananas – they are a good source of vitamin B6 and supply tyrosine and tryptophan, all of which are needed to make the feel-good brain chemicals, dopamine and serotonin. Another helpful hack is to include fruit and vegetables rich in the phytochemical quercetin
; this is because quercetin inhibits the enzyme that breaks down these feel-good hormones. Useful inclusions are kale, berries, apples, onions and grapes.
Mood booster – choose a colourful variety of whole fruit and vegetables, rather than juices. Frozen are a great choice when the fresh equivalent is out of season.
2. Eat the right fats
The type of fats we eat can affect our mood. That’s because the right fat contributes to the flexible structure of our brain cells and plays an important role in brain development. We typically refer to these fats as essential because we have to get them from the foods we eat. Of particular note are the omega-3 fatty acids which are found in oily varieties of fish like salmon, trout and sardines. These supply potent forms of omega-3
– called docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) – consumption of which is linked to lower levels of depression
, most notably in women. Oily fish are also a valuable source of vitamin D
which appears to be extra helpful for supporting the cognition of older adults. The relevance of this is clear when we realise our enjoyment of life is dependent on being able to focus, learn and have good memory.
If you prefer not to eat fish or you follow a plant-based diet, look to chia seeds, flaxseeds, hemp seeds and walnuts. However, be aware that plant sources supply a less active form of omega-3 and so, depending on your circumstances, you may need to consider a supplement
. Whether you are vegan or not, a handful of nuts and seeds has additional benefits – they supply mood-boosting nutrients including tryptophan, the precursor to serotonin, as well as zinc and iron. Another beneficial fat to include in your diet is extra virgin olive oil; studies suggest
the polyphenols it supplies helps protect the brain from the effects of ageing and, in so doing, may improve memory.
– make at least one portion of your weekly fish intake
an oily variety, if you don’t eat fish, include a tablespoon of ground seeds and a handful of nuts daily.
Reducing your sugar intake
, eating regular meals and minimising your consumption of refined carbohydrates helps stabilise blood sugar levels and prevents the swings which inevitably lead to irritability. Choose fibre-rich foods which have lower GI values and opt for whole foods
rather than packaged or processed options. Eating this way slows your digestion and allows for a steady and sustained release of glucose which your brain, mood and energy levels will thank you for.
Mood booster – get your sugar hit from whole fruits and use sweeter tasting veggies like sweet potato, butternut squash and beetroot in meals. Swap sugary drinks for sugar-free options, the best being water – aim for 6-8 glasses per day.
4. Eat gut-friendly foods
Frequently dubbed ‘the second brain’, our gut plays an important role in keeping our moods lifted. For this reason, following a gut-friendly diet which supports your gut microbiome is key. Minimise your use of processed foods, which often contain additives such as emulsifiers – these may disrupt beneficial gut bacteria. Include fermented foods daily such as kefir, sauerkraut, miso, kimchi and live yogurt – these top up levels of good gut bacteria. Wholegrains, as well as legumes, contribute the fibre needed to fuel our gut microbes, so by including oats, wholewheat bread or pasta and pulses in your diet, you’ll be helping your gut microbes prosper. If you’re not used to fibre in the diet, start slowly. One option is to support your gut microbes by creating resistant starch – you can do this by cooking and cooling rice, pasta and potatoes. This method of preparation changes the chemical structure of the carbohydrate, creating a starch which behaves more like fibre – this will keep you fuller for longer, slows the release of energy and fuels your gut microbes.
Mood booster – when buying fermented foods check labels for descriptions such as ‘raw’, ‘unpasteurised’ or ‘contains live cultures’.
5. Eat adequate amounts of protein (with carbs)
Levels of the feel-good brain chemicals serotonin and dopamine are influenced by what we eat, as well as the amount of physical activity we do. Our brain uses the amino acid tryptophan to make serotonin, but whilst this amino acid is plentiful in animal foods including turkey and tuna, studies suggest it’s not necessarily the meat-based meals which optimise our serotonin levels. That’s because when we eat protein-rich foods, competition from other amino acids can prevent tryptophan from entering the brain. Instead, studies suggest by eating a carbohydrate meal with protein we promote insulin release, which encourages our muscles to absorb competing amino acids. This makes it easier for tryptophan to increase serotonin levels in the brain. All of which supports the idea that plant-based proteins combined with complex carbs such as wholegrains and legumes may be a better dietary strategy for those with low levels of serotonin.
Mood booster – include plant-based sources of tryptophan, such as sunflower and pumpkin seeds, soya, mushrooms, peas and leafy greens, as well as dairy and poultry. Useful tyrosine-containing foods, which help support dopamine levels, include peanuts, almonds, pumpkin and sesame seeds, soya and dairy as well as lamb, beef and dairy.
If you experience mild to moderate forms of low mood or anxiety, use these suggestions as a means of supporting your mental well-being. However, if you are on mood stabilising medication and/or experience significant mood-related issues, please consult your GP before you make any significant change to your diet. It is important to seek emergency assistance if you are experiencing thoughts of self-harm.
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This article was published on 16th December 2020.
Kerry Torrens BSc. (Hons) PgCert MBANT is a BANT registered nutritionist® with a postgraduate diploma in personalised nutrition & nutritional therapy. She is a member of the British Association for Nutrition and Lifestyle Medicine (BANT) and a member of the Guild of Food Writers. Over the last 15 years she has been a contributing author to a number of nutritional and cookery publications including BBC Good Food.
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