We are all familiar with the feeling of butterflies in the stomach before a big presentation or when you lose your phone. But the connection between our brain and our gut goes much deeper than a few nervous knots. In fact, scientists now refer to our digestive system as “the second brain” and it can have a huge impact on our mood and how we respond to stress.
So what exactly is the link between our gut and our head? You may be familiar with the idea that our central nervous system (CNS) is made up of our brain and spinal cord. In fact, our gut has a nervous system all of its own, consisting of billions of neurons (nerve cells) which line the digestive tract.[1] This is called the enteric nervous system and it is responsible for how we digest our food. It forms part of the automatic or involuntary response, meaning it doesn’t need conscious thought to function.
As such, it is intimately connected to our stress response: the fight-or-flight mechanism we developed thousands of years ago to defend our mud huts from attack or run away from sabre-tooth tigers. In this state our bodies revert to energy saving mode. Priority is given to increasing blood flow to vital organs and muscles so we can run away or stand and fight. Meanwhile less pressing functions – like digestion – are suppressed.
This fight-or-flight response is incredibly useful in short bursts. Unfortunately, our bodies cannot differentiate between the stress caused by acute danger and the insidious daily stressors that are now so common in our modern lives. Those unending to-do lists, pressing engagements and urgent deadlines mean our inborn stress response is often stuck on high alert. This can have a huge effect on how well we digest and absorb our food on a daily basis.
So how does this effect mood? The enteric nervous system secretes messengers that communicate back and forth between the gut and the brain via the vagus nerve. This “second brain” is filled with the same kinds of neurotransmitters found in the brain in our head. Perhaps the best known of these is serotonin, the feel-good hormone vital for a calm and happy mind. Your gut accounts for 90% of the serotonin production in your body, so if your digestion is under par, it is likely your mood will be too.
Chronic stress can take many forms, from deadlines, meetings, social demands or even eating too much sugar or processed foods. As your brain and your gut are in constant communication with each other, upset in your digestive tract can have a direct impact on your mood, and vice versa.
The good news is that eating a diet rich in wholesome, nutrient-dense foods that support your gut can have a huge influence not just on your digestion, but on your mental health and wellbeing too. Here are my top ten foods to help boost your mood and keep your tum happy:
Foods for mood
Probiotics
These include foods like apple cider vinegar, sauerkraut, pickles, kimchi and other fermented vegetables. Probiotics are good bacteria that line your gut and are responsible for a host of vital functions such as nutrient absorption, immune support and even stress reduction.
Eggs
These nutritional powerhouses are rich in tryptophan, which our bodies use to make serotonin.[2] Nuts, pumpkin seeds, sesame seeds, poultry, spirulina and fish are also good sources of tryptophan. Eggs also contain choline, which is an essential component of neuron membranes.
Green tea
You’ve probably read about the many benefits of green tea before. Along with its antioxidant properties, green tea contains an amino acid called L-theanine, which helps promote calm, enhances learning and memory and reduces anxiety.[3],[4] It does also contain caffeine however, so if you are prone to anxiety or have trouble sleeping switch to a decaffeinated version.
Dark green leafy vegetables
These veggies contain folate and magnesium, both of which are important for nerve cell health. Folate in particular is a vital component in the process the body uses to produce neurotransmitters. It is also necessary for supporting the structure of nerve cells. Spinach, kale, chard and watercress are all good sources.
Dark chocolate
Hurrah! Dark chocolate is also rich in magnesium, which has a relaxing effect on both the mind and the digestion and can be particularly useful if you suffer with constipation. Just be sure to chose the stuff that contains over 70% cacao and aim to stick to a few squares, rather than the whole bar!
Seafood
Seafood, especially oysters, mussels, clams and crab have high levels of zinc. Zinc plays an essential role in the healthy production of serotonin along with other neurotransmitters. It can be very helpful for balancing mood, especially if you suffer from anxiety.[5]
Omega-3 fatty acids
Omega-3 fats found in oily fish, flaxseeds, chia seeds and walnuts are crucial for optimal brain function.[6] Stick to smaller fish such as sardines and eat wild salmon to reduce the risk of toxin build-up.
Avocados
The good fats in avocados are important for healthy function of neuron membranes. They also contain vitamin E, which help protect brain cells and neurotransmitters from the damaging effects of free radicals.
Blueberries
Or indeed any brightly coloured vegetable or fruit such as red and yellow peppers, kiwi, strawberries and mango. These foods are rich in vitamin C which is needed for the creation of neurotransmitters.
Bone broth
Bone broth is incredibly soothing for the gut lining, helping to promote healthy digestion and quell inflammation. It is also a good source of vitamin B12 which is important for the health of neurotransmitters in the brain which regulate mood.[7]
Food is a powerful tool for balancing mood and supporting mental wellbeing. If you would like further help in this area I offer a Mind-Body Wellness programme specifically designed to combat the effects of stress, support healthy gut function and boost mood. Visit my website to find out how I can help.
[1] Yoon S, Grundmann O, Koepp L (2011) Management of IBS in adults: conventional and complementary/alternative approaches. Alternative Medicine Review 16: 134-150.
[2] Richard DM, Dawes MA, Mathias CW, Acheson A, Hill-Kapturczak N, Dougherty D (2009) L-Tryptophan: Basic Metabolic Functions, Behavioral Research and Therapeutic Indications. International Journal of Tryptophan Research 2: 45-60.
[3] Park SK, Jung IC, Lee WK, Lee YS et al. (2011) A combination of green tea extract and L-theanine improves memory and attention in subjects with mild cognitive impairment: a double blind placebo-controlled study. Journal of Medicinal Food 14: 334-343.
[4] Nathan PJ, Lu K, Gray M, Oliver C (2006) The neuropharmacology of L-theanine: A possible neuroprotective and cognitive enhancing agent. Journal of Herbal Pharmacology 6: 21-30.
[5] Cyhlarova E, Hart G (2011) Nutrition and mental health. Nutrition Practitioner 12: 4-16.
[6] Hanciles S, Pimlott Z (2010) PUFAs in the brain. Biochemical Imbalances In Disease. Ed. Nicolle L, Woodriff Beirne A. London: Singing Dragon.
[7] Tiemeier H, van Tuijil HR, Hofman A, Meijer J, Kiliaan AJ, Breteler MM (2002) Vitamin B12, folate and homocysteine in depression: The Rotterdam Study. American Journal of Psychiatry 159: 2099-2101.
