Alice Whitehead delves into the gut-brain connection and finds out how what we eat can affect how we feel
Ever felt the crashing low after a sugary snack? Or the brain fog when you’ve not drunk enough fluids? Mood swings aren’t just connected with the chemicals in our brains but also with what’s going on in our stomachs – bringing a whole new meaning to the idea of ‘emotional eating’.
Recent research has suggested a deep-rooted correlation between mental stress and the stomach, starting with the colony of microbes (or gut flora) – part of your body’s ‘microbiome’ which produce neurotransmitters. As these microbes send messages between the stomach and the brain they are, among other things, responsible for 95 per cent of the body’s serotonin supply, which contributes to our happiness and well-being.
“The mind and the body are not separate entities so it makes sense that what you eat affects how you feel,” says Fran Taylor, AfN registered nutritionist (thebrightonnutritionist.co.uk). “Research has shown that better quality diets are consistently associated with reduced depression risk, while unhealthy dietary patterns – higher in processed foods – are associated with increased depression and often anxiety.”
Ultimately, food is not just about nutrition, says registered dietitian Claire Pettitt (clairepettitt.com). “It also carries with it associations with pleasure, reward and certain emotions and memories. Eating with friends and family, social occasions and celebrations can bring joy and happiness but stress also affects our eating habits and can lead to over-eating and comfort eating, or even losing our appetite completely,” she says.
One of the biggest mood-influencing factors is not necessarily what we eat, but when we eat it. Lack of fuel, missed meals or irregular eating patterns can all create imbalances in insulin production that promote stable blood sugar levels. “Our brain accounts for 20 per cent of our body’s total energy needs so it requires regular feeding to keep us feeling our best,” says Fran. “If you’ve experienced feeling ‘hangry’ you will know just what this means! This happens when our blood sugar levels fall and our concentration and mood drops.”
Having a regular, varied and colourful plant-based diet – choosing whole foods (i.e. minimally processed foods) and including some oily fish, dairy, unprocessed lean meats, and plenty of nuts, seeds and legumes – is the best way to enhance your mood through diet. But why is this and which nutrients are important?
Many foods have a mood enhancing effect – helping to promote feelings of pleasure, calm and happiness.
“Serotonin is an important mood enhancing chemical messenger in the brain and it is produced from tryptophan,” says Claire. “Tryptophan is an amino acid and is found in foods containing protein such as eggs, fish, chicken, cheese, nuts, seeds and tofu. But it is better absorbed when carbohydrates are also present in the diet, so it is important to have your protein rich food with a wholegrain carbohydrate source such as rice or wholegrain bread.”
Magnesium has also been linked to a reduction in anxiety. “Recent research from the University of Leeds, which looked at numerous studies into the effects of magnesium on stress, concluded that there was significant evidence to suggest that behavioural effects of stress exposure, such as anxiety could be reduced by magnesium,” says Emma Scott, a nutritionist from the Federation of Holistic Therapists (nutrilife.uk.com). “Spinach, in particular, contains high levels of magnesium, which has been linked with counteracting stress by binding to and stimulating gamma amino-butyric acid (GABA) receptors in the brain, which improves mood by reducing irritability and depression to help us feel calm.”
Foods for focus
Indeed, it’s those GABA receptors that can help us with focus and concentration too. “GABA helps the brain filter out extraneous information, enabling us to stay focused and calm,” says Emma. “Protein (including fish, turkey, eggs, nuts and legumes) is made up of amino acids, which are chemical structures that form the foundation of our neurotransmitters. These amino acids need specific vitamins and minerals to help facilitate enzymatic reactions in order to convert the amino acid into functioning neurotransmitters that control our mood. The amino acid glutamine, the principal building block of GABA, can be found in halibut, legumes, brown rice and spinach – but try to eat these with vitamins B3, B6 and B12 to help convert glutamine to GABA.” And if you want to find your mojo, it might just be in your meal too. “The amino acid tyrosine, found in eggs, is a powerful ‘Mr Motivator’,” adds Emma. “It plays a vital role in the normal functioning of dopamine, the brain chemical which make us feel positive, motivated and leaves us with a sense of achievement and pleasure.” Omega-3 fats, found in oily fish such as mackerel and salmon, walnuts and flaxseeds, are associated with focus and cognitive ability. “Research into the effect of omega-3 fatty acids on mood disorders by La Trobe University in Australia revealed evidence to support findings that increasing levels of omega-3 is essential for brain function and can help to reduce depression,” adds Emma.
Beating the blues
While some vitamins and minerals trigger good moods, low levels of calcium are linked to an increase in PMS and depression, it’s thought that chromium deficiency may effect blood sugar levels, and dips in folate can cause fatigue. “Studies from Stanford University show calcium is an important mineral element in the process of neurotransmitter release,” Emma explains. “This is very important post menopause as there is a decrease in oestrogen levels, which reduces our ability to absorb calcium.” Vitamin D deficiency has also been linked to mood disorders and depression, says Claire. “Our bodies make vitamin D when our skin is exposed to the sun so getting outside can help production but it is also important to get vitamin D from foods such as oily fish, eggs, dairy products and mushrooms.”