Maybe it’s just a gut feeling
Our diet and food system have changed significantly in the past 100 years. With the rapid industrialisation of food supply, advent of supermarkets, rise of big agriculture, and now, tech-enabled takeaway, our bodies, brains and minds are crippling under the weight of dietary change. Nutrition is a poorly considered factor in mental health, particularly in mainstream healthcare which predominantly relies on pharmaceutical interventions to address chemical imbalances – typically dopamine and serotonin – in the brain. Yet, the root cause of neurochemical disturbance has scarcely been understood.
But science is catching up and research on the gut-brain connection has highlighted the impact of food and gut function on how we think and feel. The emerging field of nutritional psychology, together with advances in neuroscience and evolutionary biology are beginning to reveal the link between our diet and state of mind. So can food really change your mood?
Yes! The contents of your tummy and its nutritional quality play a fundamental role in determining brain function, mental clarity, and emotional disposition. In outstanding discoveries over the past two decades, scientists have found that the gastrointestinal tract is inhabited by millions of tiny microbial organisms. These include bacteria, fungi, archaea, protozoa and viruses (sounds other-worldly), the majority of which largely reside in the gut, and collectively form what is known as the microbiome. In fact, researchers have been able to estimate that the average human body is made up of more of these tiny microbes than actual human cells (yep, that’s right!).
It’s hard to fathom that our body exists in a kind of codependent relationship with trillions of bacteria. Though microbiome science has reinforced the link between symbiotic (good) and pathogenic (bad) microbiota, and overall health, mental clarity and perception, and emotional wellbeing. Disruption to the natural balance of the microbiome through factors such as stress, poor diet and low nutrient absorption, as well as persistent antibiotic use can cause dysbiosis (imbalance) and inflammation.
Evidence indicates that disruption to the natural ecology of our intestinal lining is linked with mental disorders including depression, anxiety, panic, delirium, psychosis, cognitive decline, and even autism. So much so that the term, ‘psychobiome’ is starting to make an appearance in science circles. And now studies are looking at the role of ‘psychobiotics’ – targeted probiotic therapies that flush your system with an abundance of the good bacteria to balance out the bad guys – in the management of mental disorders.
And if that doesn’t sound wacky enough, over 90 percent of serotonin in the body is actually produced by the bacteria in your gut, and not your brain. Furthermore, a network of sensors in the intestinal tract feeds information to the brain through a superhighway known as the Vagus nerve. Neural senses connected to the Vagus nerve can detect the presence of sugar in the microbiome, and send signals to the brain triggering a release of the chemical neurotransmitter dopamine (hello sugar high!). Too little or too much dopamine has been attributed to many mood disorders.
As it’s now well established that what we put in our mouth affects our entire system, both the physical and mental, what you’re experiencing might not just be in your head after all but in your body and belly too. However, in a sea of diet fads – keto, paleo, plant-based, low-carb, raw...the list is endless – it can be hard to determine what is most suitable for your needs. The best advice is to do your research and consider working with an expert doctor, nutritionist or health coach. And most importantly, always go with your gut.
This article was first published in The West Australian in Renée Gardiner’s weekly column in Agenda, 10 April 2021.