The link between what we eat and the way we feel might seem like a “no brainer”, but funnily enough, meaningful scientific studies into how our diets influence our mental health conditions including anxiety and depression is only a relatively new area of nutrition research.
Our brains are highly sensitive to what we eat. Studies on animals commonly show how poor diet can negatively impact on brain function. This link is much harder to demonstrate in humans, however researchers from Deakin University used MRI scans to measure the size of the hippocampus (a part of your brain directly involved in learning and memory as well as mental health and wellbeing), finding that diets based heavily on refined carbohydrates, fast foods and sugar-sweetened beverages can actually shrink parts of your brain1.
Every food choice we make can either help to balance our mood or stress us out. So here’s three strategies you can incorporate into your diet to help boost mood and support our healthy stress response function:
Ditch the highly-processed, refined carbs
Highly-processed carbohydrates (white bread, white rice, cakes, biscuits and sugary foods and drinks) can negatively impact on our moods, mental health and wellbeing in three distinct ways:
- They displace healthier, more nutritious foods in your diet and can lead to potential nutritional deficiencies (particularly vitamins, minerals, antioxidants and essential fatty acids).
- The high Glycaemic Index (GI) of these carbohydrates cause rapid increases and rebound drops in blood sugars, which can contribute to mood swings.
- They trigger low-grade, chronic inflammation in the body, which is linked to mental health conditions including anxiety and depression2.
Nutrition tip: Don’t avoid all carbs – just eat most of your carbohydrates in the form of vegetables, fresh fruit, legumes and whole grains.
Focus on your gut
It seems that one of the answers to a clear, relaxed and happy brain may lie with the microscopic bugs (bacteria) living inside our digestive system. More than 90 per cent of our dopamine and serotonin (feel good neurotransmitters that send signals from our brain and around our bodies) are actually produced by our beneficial gut bacteria.
To boost beneficial gut bacteria (and support production of dopamine and serotonin):
- Include fermented foods like live-cultured yoghurt, kefir, kombucha, tempeh and kimchi in your diet. These foods contain beneficial gut bacteria (probiotics).
- Base your diet on vegetables, fruits, wholegrains, nuts, seeds and legumes. These foods have pre-biotic properties (they act like fertilizer for your good gut bacteria).
Stick to tradition
Study after study points to a good-quality, balanced diet being important to mental health. In fact, a recent Australian randomized control trial prescribing a Mediterranean diet for individuals with clinical depression showed significant improvement in dietary quality and association with improvements in depressive symptoms3.
But it’s not just the Mediterranean diet that has been shown to be helpful – any ‘traditional diet’ is associated with a lower risk of mental health conditions. The common element seems to be whole, minimally-processed, nutrient-dense foods2. The benefits of the Mediterranean diet (fruits, vegetables, whole grains, olive oil, nuts, fish) have been recognised for many years, however research also demonstrates that traditional Norwegian diet (fish, shellfish, game, root vegetables, dairy products, wholemeal bread) and the traditional Japanese diet (fish, tofu, rice, steamed greens) may be just as beneficial in the prevention of anxiety and depression. A reliance on unprocessed ‘real’ foods appears to be the key factor in these positive health findings.
Disclaimer: nutrition and healthy eating is only one component of mental health management. If you are concerned that yourself or someone close to you is suffering mental health issues, seek professional medical help and support.
To learn more about how nutrition and exercise impacts on our mental health wellbeing, stress-response, anxiety and depression states, check out our mental health nutrition course.
- Jacka, F., Cherbuin, N., Anstey, K., Sachdev, P. and Butterworth, P. (2015). Western diet is associated with a smaller hippocampus: a longitudinal investigation. BMC Medicine, 13(1).
- Molenddijk, M., Molero, P., Ortuno Sanchez-Pedreno, F., Van der Does, W. and Angel Martinez-Gonzales, M. (2018). Diet quality and depression risk: A systematic review and dose-response meta-analysis prospective studies. J Affect Disord.
- Opie, R.S., O’Neill, A., Jacka, F.N., Pizzinga, J. and Itsiopoulos, C. (2017). A modified Mediterranean dietary intervention for adults with major depression: Dietary protocol and feasibility data from the SMILES trial., Nutr Neurosci, PMID: 28424045.