Seeking the Root Cause of Mental Health

Want to improve mental clarity? How about reducing anxiety and depression? The answer could be in dirtying up your diet. Creating a diverse and thriving microbiome is key to all aspects of health, and mental health is no exception.  
In recognition of Mental Health Awareness Month, and with nearly 8% of American adults currently suffering from depression and over 18% from anxiety, it is increasingly urgent to explore why. [1] What could cause so significant a portion of us to go to battle within our own brains? 
Well, Old Man Winter usually takes the brunt of the blame. His cold temperatures and gray skies are, for many, too much to endure for an extended period of time. However, scientists are beginning to wonder if a different kind of environment may be a key player. Though it is not one we can step into; rather it resides within us. This “environment” is our microbiome, and even though we may call it “ours,” only a slice is made of our own material. The rest is populated by 10—100 trillion foreign bodies, mostly bacteria, that outnumber our own cells ten to one. [2][3] It’s easy to imagine how these tiny tenants play their respective roles in digestion or immuno-interactions, but what may surprise you is the subtle ways in which they may affect our mental state. 

The Gut-Brain Connection

At the root of the relationship between our mind and our microbes is the nervous system, a major mode of communication between the two. The vagus nerve, specifically, directly links the stomach to the brain, transmitting the hormonal, neuronal, and bacterial changes occurring in the bowel. [4] Some of the traffic travelling this route are the neurochemicals produced by gut bacteria in the hundreds, which the brain depends on to regulate physiological and mental processes, including mood. Notably, gamma-aminobutyric acid (GABA) and serotonin both bloom in the microbiome, the latter originating there almost entirely. [3] Serotonin is thought of as a mood stabilizer, reducing depression and regulating anxiety. [5] GABA, similarly, is considered to have a calming effect, and is believed to reduce anxiety and fear. [6] Here we begin to see the significance that our micro-stowaways have when it comes to our mental state: they carry much responsibility for our chemical balance. 
Looking out the window, considering spring, a parallel can be drawn. No matter how much work pollinators put in, our backyard biomes will bud-up only if they are well nourished; bright sunlight, fertile soil, and fresh rainwater must be had for plants to flourish. Our microbiomes are similar in this way. As the flower in our pot needs nourishment, so does the flora in our gut. Yet with our brain, stomach, and vagus nerve in place, populated by a plethora of bacteria that are supposed to be producing mood-managing neurotransmitters, we still struggle with feelings of fear, anxiety, and depression.  

What is the Solution?

The details are in our diet, which has gradually become devoid of essential nutrients as we’ve modernized it over the last few-hundred years. Traditional diets were composed of whole foods superior for mental health, full of readily available vitamins, minerals, fatty acids, fibers, and prebiotics that presented a boon to our ancestors’ microbiomes. [7] Scientists are beginning to think that this dietary bankruptcy plays a key role in the development of depression and, furthermore, that a healthy diet may prevent it. [8] 
So, it would appear that we need to take a page out of the cookbook of our ancestors, and dust off those pre-industrial recipe cards. We must fill our plates with fermented foods and garden-grown vegetables. These are just some of the nutrient-dense foods that our gut and its trillions of residents will thrive on, and as they thrive, so will we. For instance, one study found that young adults who regularly ate fermented foods were less likely to suffer from social anxiety, likely because those foods supplied their internal environment with nutrients necessary for the proper production of important neurochemicals. [9] When well-fed, our good mood may blossom in tandem with spring.  
On that note, after a whole-food, spring-inspired meal, take a minute to be in it: roll around in the grass, stick your hands in the dirt, meet a few new micro-friends. You’ll be happier for it. 

Resources 

  1. “Facts & Statistics.” Anxiety and Depression Association of America, ADAA, adaa.org/about-adaa/press-room/facts-statistics.  
  2. Ursell, Luke K et al. “Defining the human microbiome.” Nutrition reviews vol. 70 Suppl 1,Suppl 1 (2012): S38-44. doi:10.1111/j.1753-4887.2012.00493.x 
  3. “That gut feeling.” Monitor on Psychology, American Psychological Association, www.apa.org/monitor/2012/09/gut-feeling.   
  4. Evrensel, Alper, and Mehmet Emin Ceylan. “The Gut-Brain Axis: The Missing Link in Depression.” Clinical psychopharmacology and neuroscience: the official scientific journal of the Korean College of Neuropsychopharmacology vol. 13,3 (2015): 239-44. doi:10.9758/cpn.2015.13.3.239 
  5. “Serotonin: What You Need to Know.” Healthline, Healthline Media, www.healthline.com/health/mental-health/serotonin#takeaway 
  6. Link, Rachael. “What Is GABA? The Brain-Boosting, Anxiety-Busting Power of GABA Supplement.” Dr. Axe, 14 Nov. 2017, draxe.com/gaba/. 
  7. Deans, Emily. “Microbiome and mental health in the modern environment.” Journal of physiological anthropology vol. 36,1 1. 27 Jun. 2016, doi:10.1186/s40101-016-0101-y 
  8. Evrensel, Alper, and Mehmet Emin Ceylan. “The Gut-Brain Axis: The Missing Link in Depression.” Clinical psychopharmacology and neuroscience : the official scientific journal of the Korean College of Neuropsychopharmacology vol. 13,3 (2015): 239-44. doi:10.9758/cpn.2015.13.3.239 
  9. Pedersen, Traci. “Fermented Foods Linked to Decreased Social Anxiety.” Psych Central, 8 Aug. 2018, psychcentral.com/news/2015/06/12/fermented-foods-linked-to-decreased-social-anxiety/85640.html.