The Gut-Brain Connection: Nutrition’s Role in Mental Health

by Jane Wood (posted with permission)
Our current medical model of clinical care for the treatment of mental illness focuses on pharmaceutical and psychotherapeutic approaches with limited consideration of holistic interventions, such as nutrition. The intention of this article is not to down play the importance of clinical options to mental health care, rather to shine awareness on the role nutrition plays in a mental health treatment plan. As the medical community continues to investigate ways to develop more comprehensive treatment plans for mental illness, we gain a greater understanding of nutrition and its link to mental wellbeing. Let us start with the gastrointestinal system to understand its relationship to mental health. You may have heard that the gut is our second brain, but what does that really mean? The gastrointestinal system, also known as the digestive system, starts with smelling food and continues through the body until waste is eliminated. It is the process where the body receives the nutritional resources it requires to support all human functions, including the brain. In a healthy brain, neurons, or the communication cells, tell the body how to behave. To do this it relies on a steady supply of chemicals called neurotransmitters, which are responsible for regulating feelings and emotions. Some of these are known as serotonin, dopamine and norepinephrine. In people who are diagnosed with a mental illness such as Major Depressive Disorder, Bipolar Disorder, Generalized Anxiety Disorder, Schizophrenia or with a Post-Traumatic Stress Injury, something disrupts how the brain sends and receives its messages. The good news is, often these illness can be managed by taking pharmaceuticals containing the neurotransmitters that are impaired. So what does this have to do with the gut? The brain and digestive systems are connected by the Central Nervous System (CNS) through the gut-brain axis. As mentioned earlier, the brain communicates using neurons and neurotransmitters. There are over 100 billion neurons found in the brain and 500 billion in the gut, this is how the two talk. Similarly, neurotransmitters are produced in the brain with a majority of them also produced by cells and bacteria in the gut. The main nerve used in this communication process is known as the Vagus nerve, the largest nerve in the CNS, running from the guts to the brain. Any stress on the body, can damage this vital communication process resulting in either a mental or gastrointestinal disorder and in some extreme cases both. There is one last thing to discuss before we learn how nutrition assists in mental health, the immune and inflammation responses. The immune system plays an important role in our health, including mental wellbeing. The body’s normal immune response is designed to attack toxic or foreign invaders in the body, neutralizing the threat and we usually feel better. However when the body is exposed to extreme amounts of stress whether physical, chemical or emotional; our immune system starts to act in unusual ways. When the body starts to see everything as an immune threat and stays turned on for too long it leads to undesirable and persistent inflammation. The inflammatory response, like the immune one, is the body’s way to promote healing when we are wounded. Constant demands on these system have negative impacts on our vital body functions, especially the gastrointestinal system. When digestion is malfunctioning nutrition is not being absorbed, leading to more stress on the body thus demanding more from the immune and inflammatory systems – and the circle continues. It is well researched that when these systems are not functioning it can lead to an increase of symptoms in mental illness especially depression, dementia and schizophrenia. So how can food help? Hippocrates famous quote says “Let food be thy medicine and medicine by thy food.” The prevention and healing of all health conditions can be greatly assisted by paying attention to the food we consume to fuel our body. Unfortunately, in today’s world we move at such a fast pace it was only natural that our food also followed this trend. This results in humans consuming excessive amounts of highly processed food. In addition to being nutritionally deficient, these foods cause major stress on the body which further dysregulates immune and inflammation functions as described above. This plays a negative role in symptom management in people living with mental illness. The more processed food we consume, the more likely our mental wellbeing will suffer. It is impossible to describe all of the dietary changes required to support mental health in just one blog. The aim of this article is to start thinking about the foods we eat and how they either benefit or damage our health. To start, regardless if you have been diagnosed with a mental illness or if you are living a regular stress filled life, we can all reduce the amount of processed foods we consume. Begin by reading nutrition labels and ingredient lists and consider the following recommendations: • Aim for no more than 4 grams of added sugar daily; • Avoid artificial sweeteners as they can cause the same damage to the body as regular sugar; • Eliminate foods that contain trans fatty acids, such as chips, crackers, frozen prepared foods and most fast food items; • Choose foods that contain 5 ingredients or less; and • Avoid “white” foods such as bread, pasta, cereals and baked goods made with white flour. As this blog series grows we will explore in depth the role nutrition plays in the healing process, especially for those walking a mental health journey. It is our hope that you gained some insight into how our digestive system and brain are connected and to begin shifting our beliefs surrounding mental illness and nutrition. Jane Wood The Mindful Nutritionist