Did you know that what we eat can impact our mood? Abigail Attenborough, our nutritionist, explains the relationship between food and how we feel.
The negative impacts of a poor diet and mental health have become increasingly clear in the science literature over the past few years. It has been long thought that the brain and body are separate entities, but the reality is we are one tightly integrated complex system.
Such as can be seen by the communication between our brain and gastrointestinal (GI) tract, sometimes referred to as a ‘superhighway’. The gut and brain are connected through many chemicals called neurotransmitters such as serotonin and GABA (gamma-aminobutyric acid), which contributes to feelings of happiness. In fact approximately 70-90% of serotonin comes from the gut!
The GI tract is populated with both good and bad bacteria - this is called the microbiome. Overabundance of some bacteria can resort to common psychological disorders such as depression, anxiety and Obsessive Complusive Disorder, as well as inflammation of the GI tract causing gastrointestinal disease such as Irritable Bowel Syndrome and Crohn’s disease. Studies show bad bacteria can be exacerbated by a Western diet; one that is higher in processed foods including added sugar, salt and fat. Fortunately, on the other hand, having a wealth of good bacteria in your gut can help promote wellbeing, relaxation, and feelings of reduced anxiety by releasing GABA in the brain. Promoting good health should extend to include the health of your brain as researchers are now finding more concrete evidence that the composition of bacteria in your gut can affect our mental health.
How can you promote the health of your microbiome for better mental health?
Studies showing a link between diet and mental health have found associations with whole dietary patterns, not just specific nutrients. Meaning there is no one ‘superfood’ for mental health; rather, it is important to eat a balanced whole-foods diet to help nourish our microbiome. A whole-foods diet approach can be defined as: a high intake and wide variety of a plant-based foods such as fruit, vegetables, whole-grains, nuts and seeds; a moderate intake of quality proteins such as seafood, lean meats and dairy; and a low intake of highly processed foods.
A diet that includes foods with probiotic and prebiotic ingredients. Probiotic foods contain live beneficial bacteria and include plain yogurt (if you can tolerate dairy), kefir (fermented milk drink similar to a thin yogurt), cottage cheese, fresh raw sauerkraut, kimchi, kombucha, beet kvass (similar to kombucha), apple cider vinegar, natto (fermented soy beans), and miso. Keep in mind that the probiotic effects of these foods are destroyed by cooking, processing, or preserving at high temperatures and thus most need to be kept in the fridge. Prebiotic substances are specific types of indigestible fibre that nurture the growth of probiotic bacteria. They do not contain living organisms, and are consumed by probiotics.
Prebiotic foods include artichokes, leeks, onions,
garlic, chicory, cabbage, asparagus, legumes, and oats.
Other food groups specifically beneficial for the gut-brain connection are omega 3’s such as oily fish, flax seed, and chia seeds. High-fibre foods such whole grains, nuts, seeds, fruits and vegetables all contain prebiotic fibres. Try to consume plenty of soluble fibre and resistant starch in particular. Soluble fibre promotes the survival of beneficial gut flora and can have a soothing effect on the gut; this is because it dissolves in the body and creates a gelatinous structure as it passes through the GI tract. Starches such as sweet potatoes, white potatoes, plantain, taro, and green banana flour are particularly good sources of resistant starch, and well as lentil and beans which are also soluble fibres.
Polyphenol-rich foods such as cocoa, green tea, olive oil all contain polyphenols, which are plant chemicals that are digested by your gut bacteria. Polyphenols increase healthy gut bacteria and may improve cognition. If you’re reaching for dark chocolate to get your polyphenol hit, ensure it is above 70% cocoa.
Serotonin boosting foods are important to help stabilise ones’ mood. These include eggs, (especially the yolk), salmon, nuts and seeds. Tryptophan is an amino acid that is converted into serotonin. Foods that are high in tryptophan include turkey, eggs, cheese and soy products such as tofu - many protein-based foods.
Remember a healthy diet doesn’t need to be hard work, following the guidance above and eating real whole-foods, whilst avoiding processed food as much as you can is a great way to promote gut health! Keeping convenient, healthy foods on hand can make it easier to make healthy food choices every day!
by Abigail Attenborough