Kate Save, Accredited Practicing Dietitian, Exercise Physiologist and CEO and Co-founder of Be Fit Food examines the link between our brain and our gut.
Thank you for reading this post, don't forget to subscribe!You might be surprised to learn that our bodies have ten times more bacterial cells than human cells – that equates to our bodies being made up of a mind-boggling 90% bacteria and just 10% human. Now digest that information for a minute.
What’s more, our entire human DNA would fit in our big toe, while our bacterial DNA takes up the rest of our body. So, should we be taking better care of our bacteria? You bet we should.
Our gut is lined with billions of bacteria and these work hard to keep our entire bodies healthy. In fact, these bacteria even have the ability to control our bodies by activating and deactivating particular genes. Incredibly, 95% of the Serotonin (a neurotransmitter that controls our sleep, appetite and mood) that our bodies produce comes from our gut and a connection between our brain and our gut allows them to interact. Therefore, our digestive system has the remarkable capacity to control our emotions. As neurotransmitters are highly influenced by our gut bacteria, it makes sense that the food we eat contributes significantly to our mental health.
A number of studies have shown a correlation between lower incidence of mood conditions such as depression and anxiety in those who consume a plant-based Mediterranean-style diet, when compared with those who eat a more processed Western diet, which is usually high in refined sugars. Research has also shown that a plant-based Mediterranean diet can reduce the risk of cognitive decline associated with conditions such as dementia.
An eating plan known as the MIND diet, which combines Mediterranean and DASH diets, is made up of natural, plant-based foods with an emphasis on increased intake of berries and leafy green vegetables, and reduced intake of animal-based foods and high saturated fat. The MIND diet has unsurprisingly become popular as a strategy to aid the prevention of cognitive decline.
The rich foods that make up the Mediterranean diet include vegetables, fruits, nuts, seeds, legumes, unprocessed grains plus small amounts of lean meat, chicken, fish, eggs and dairy products. Plant-based foods also contain a lot of dietary fibre – the main source of food for the microbiome (gut bacteria). The types of dietary fibre are insoluble fibre, soluble fibre and resistant starch and by eating a variety of plant-based foods, we introduce all of these dietary fibres and develop diversity in our microbiome. This then creates the balance in gut-health that is linked to improved wellbeing.
Omega-3s, which are abundant in the Mediterranean diet, are also important for protecting our cognitive function. They help us to maintain neuronal function and cell-membrane integrity within the brain. Omega 3 fatty acids include; alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). Oily fish such as salmon, tuna, sardines and trout are rich in Omega-3s.
Good brain health also requires antioxidants and the foods that are rich in these include fruits, vegetables, nuts, seeds and legumes. Plant foods contain antioxidant levels that are over 64 times higher than the average animal-based foods. Antioxidants help to prevent cell and DNA damage – they also boost the immune system and prevent inflammation throughout the body.
Limiting saturated fats and refined sugars is also very important for brain health as these can have a negative impact on brain proteins. These proteins are called neurotrophins, and they protect the brain against oxidative stress and promote the growth of new brain cells. Deep-fried or highly processed and preserved foods, as well as packaged foods like biscuits and chips, and cheese, animal fat and fat used for cooking such as butter, lard, ghee and cream should all be avoided.
Understanding and respecting the critical link between our gut and our brain can help us to choose our foods wisely. The benefit of doing so is a happier and healthier you – in body and soul.
Check out these Be Fit Food recipes to help you nurture your brain and gut health.
References
- Sydenham E, Dangour AD, Lim WS. Omega 3 fatty acid for the prevention of cognitive decline and dementia. Cochrane Database Syst Rev 2012;6:CD005379.
- McCann JC, Ames BN. Is docosahexaenoic acid, an n-3 long-chain polyunsaturated fatty acid, required for development of normal brain function? An overview of evidence from cognitive and behavioral tests in humans and animals. Am J Clin Nutr. 2005;82:281–295
- Gómez-Pinilla F. Brain foods: the effects of nutrients on brain function. Nat Rev Neurosci. 2008;9(7):568‐578. doi:10.1038/nrn2421
- Clapp M, Aurora N, Herrera L, Bhatia M, Wilen, Wakefield S. Gut microbiota’s effect on mental health: the gut-brain axis. Clin Pract. 2017;7(4):987.
- Evrensel A, Ceylan ME. Then gut-brain axis: the missing link in depression. Clin Psychopharmacol Neurosci. 2015;13(3):239-244.
- Murphy M, Mercer JG. Diet-regulated anxiety. Int J Endocrinol. 2013: 701967
- Gibson-Smith D, Bot M, Brouwer IA, Visser M, Penninx B. Diet quality in persons with and without depressive and anxiety disorders. Journal of Psychiatric Research. 2018;106:1-7.
- Jacka FN, Mykletun A, Berk M, Bjelland I, Tell GS. The association between habitual diet quality and mental health disorders in community-dwelling adults: the Hordaland Health Study. Psychosom Med. 2011;73(6):483-90.
- Lai JS, Hiles S, Bisquera A, Hure AJ, McEvoy M, Attia J. A systematic review and meta-analysis of dietary patterns and depression in community-dwelling adults. Am J Clin Nutr. 2014;99(1):181-97.
- Sathyanarayana Rao TS, Asha MR, Ramesh BN, Jagannatha Rao KS. Understanding nutrition, depression and mental illness.
- Psaltopoulou T, Sergentanis TN, Panagiotakos DB, Sergentanis IN, Kosti R, Scarmeas N. Mediterranean diet, stroke, cognitive impairment, and depression: A meta-analyses. Ann Neurol. 2013;74(4):580-91.
