Our small intestinal tract is nearly 20 feet long and has the surface area of a tennis court. We’ve evolved this incredible design out of necessity to absorb nutrients from the foods we eat. The increased surface area allows a tremendous amount of contact space for this to happen.
There is a direct connection between our brain and our intestinal tract. For a long time, scientists believed that it was a one-way street: the brain sends signals to the digestive tract controlling how fast we process and digest food, how quickly our intestines contract to push along a bowel movement, and how anxiety can make us feel nauseous and lose our appetite.
However, we now know it’s a two-way street – the gut also talks directly with the brain. As our understanding of probiotics and the microbiome advances, we have come to understand that there are over 100 trillion bacteria in our intestinal tract. They’re responsible for producing chemicals that influence the hormones circulating throughout our body and the neurotransmitters we produce in the brain. In fact, the majority of serotonin (the happy, feel- good neurotransmitter that signals satisfaction) produced in the body is actually made in our intestines. Deficiencies of this important neurotransmitter are associated with depression, anxiety, and OCD.
When we consume healthy foods, especially foods that contain dietary fiber, the bacteria in our intestines ferment it and produce these beneficial chemicals. These chemicals then communicate with the vagus nerve, the longest nerve in the human body. The vagus nerve then relays the messages to the brain, which in turn produces an array of neurotransmitters. This direct connection explains why the foods we consume can have a profound influence on our mood!
Consider the counter scenario. When we consume unhealthy food high in simple sugars and unhealthy fats, the balance of bacteria in our intestines can shift unfavorably. In turn, the chemicals they produce trigger cravings for more unhealthy foods and deplete the ‘happy hormones’ in our brain. Overtime we slowly develop symptoms of anxiety, depression, obsessive tendencies, and our behaviors change. Some of the greatest offenders are gluten, dairy, and foods sprayed with chemicals, like glyphosate (Roundup) and pesticides. GMOs are modified to resist pesticides and glyphosate, and so by consequence they are some of the most heavily sprayed!
Some of the best foods to incorporate in the diet are those that contain healthy dietary fiber and are chock full of nutrients. This includes green leafy veggies, like kale, spinach, chard, collard greens, broccoli, brussels sprouts, asparagus, and nearly every other green veggie. All of these foods are high in something called prebiotics. These “pre”-biotics serve as fuel for the “pro”-biotics (beneficial bacteria) that live in our intestines. The probiotics feed on the prebiotics and multiply, shifting our microbiome toward a healthy population. Other great prebiotic foods include: garlic, onions, artichokes, radishes, cucumbers, flaxseeds, cocoa, and many more. A quick Google search for prebiotic foods will reveal an extensive list.
It’s important to avoid the types of food that have a negative impact on our microbiome. These include fried and fast foods, processed meats, soda & other sweetened beverages, sugary baked goods like pastries, and candy. The common denominator in many of these foods is simple sugar. Sugar feeds many of the unhealthy gut bugs and favors the overgrowth of yeasts, like candida. As these unfavorable populations grow, they created byproducts and chemicals that cause us to crave more of these unhealthy foods. This cycle eventually leads to weight gain, depressive moods, and anxiety. Break the cycle and feed your body the food it needs to function optimally!
If you, a friend, or a family member suffers from anxiety, depression, OCD, or insomnia, I recommend following a gluten-free and dairy-free diet for at least two weeks. Incorporate several of the prebiotic foods listed above and evaluate how your symptoms resolve. Be sure to note changes in skin quality as well. The skin is our largest organ of detoxification and is also directly influenced by the foods we eat.
Dr. Matthew Castanho is a board certified and licensed Naturopathic Physician who practices medicine with the goal of addressing the true underlying cause of disease. As opposed to merely treating symptoms with pharmaceuticals, Dr. Castanho fully understands human physiology and the dietary and nutritional components that help regenerate health. Using these natural principles, he helps his patients restore optimal function to their bodies. He commits hundreds of hours annually to continuing education, always looking for the newest and more effective ways to serve and support his patients.