Cuisine and connection have made the simple art of eating a culture all its own. The social aspect of sitting down and having a good meal has taken a necessity of life and transformed it into an experience. Gone are the days when eating was purely for sustenance and health. No more gatherers or hunters are ensuring a community has enough food. For many in the Western world, food is always accessible. That has led to a disconnect between eating for taste and eating for health.
The human body needs food, not to feel satiated, but to give the processes the right nutrients to do what they’re supposed to do. Protein makes hormones and enzymes that build and repair much-needed muscle and bone. Carbohydrates are broken down into glucose and used as energy to get you through another intense day of work. Vitamins, minerals, fatty acids, and fat are also essential to the body. The food a person eats is supposed to provide all the aforementioned nutrients to keep up with every cycling demand of the body to stay as healthy as possible. But what about the mind?
The Mind-Food Connection
Nutrition can keep your heart pumping blood to all corners of your body. It can also keep your lungs breathing without you having to think about it. But did you know that it also plays a vital role in the health of your brain? In fact, without the constant function of the brain, all other processes in the body suffer. If the brain goes, it all goes. Just as a car needs a continuous stream of gasoline or electrical energy to continue down the open road, the human brain needs fuel to keep itself running. That fuel? Food.
It’s not always widely considered how crucial food quality is when it comes to brain structure and function. The health kick that has taken over in the past decade is starting to acknowledge the dire need for quality food, but it is still only considered because of physical health. Mental illness has been long attributed to as a psychological impairment as opposed to a physiological one. Mounting research is beginning to show that the two are not as separate as once thought—they are symbiotic.
The Culprits Behind Nutrition-Driven Inflammation
Too much sugar is bad for you, but not because it is an ingredient that can cause obesity. There is far more to it than that. Sugar is an inflammatory food, along with other foods such as refined carbohydrates—think white bread, pastries, you know, the fun stuff—and heavily processed foods. To put it into perspective, if there are more than five ingredients, the food is likely processed. The same can be said if the food has any added sugar, artificial additives, or ingredients you wouldn’t find in your local supermarket or cook with at home. When the diet is full of these types of foods, the body begins to think that it is at war, and the only way to make it out alive is by triggering an inflammatory response. This response by the immune system is designed to have fighter cells get rid of the invader, in this case, the pesky food ingredients. When the body becomes accustomed to the aforementioned foods, that inflammatory response can cause chronic inflammation.
Inflammatory Foods and Brain Structure
When the digestive system becomes overwhelmed by the horrible ingredients a person is giving themself, it becomes damaged. When damaged, it triggers inflammation. When inflammation begins, the brain is just as susceptible as the next organ to its effects. Brain inflammation, when experienced chronically, can alter the wiring and structure of the brain. The results of chronic inflammation are a decrease in gray matter in the inferior parietal lobule, which is the part of the brain that plays a role in emotion perception and the interpretation of sensory stimuli.
Chronic inflammation also can interfere with vital connections between brain networks. The default mode network—a network in the brain that allows regions to interact with one another—is changed with chronic inflammation. The dorsal attention network, the salience network, and the medial visual network are also changed by chronic inflammation.
When chronic inflammation continues to damage both the structure and the wiring of the brain, it leads to cognitive dysfunction, neurodegeneration, and neurologic injury. These brain issues can lead to the decline of brain function, but what does that have to do with mental illness?
The Physiology of Psychology
Many researchers believe that mental illness likely stems from the brain’s inability to properly communicate. The neurotransmission is out of whack—simple, clear, easy to understand. But that’s not entirely accurate. Take stress, for instance. Everybody feels it. It’s a normal part of life for everyone, and it’s a reaction designed to help people adapt and survive in less than ideal situations. However, too much stress can cause inflammation throughout the body. It also dysregulates the hypothalamic-pituitary-adrenal axis in the brain. The hypothalamic-pituitary-adrenal axis consists of the pituitary gland, the adrenal glands, and the hypothalamus—the part of the brain in charge of hormone release and regulation.
That is where it gets a bit complicated because it can be easy to chalk it up to too much stress equalling mental illness. But the physiological changes to the part of the brain in charge of hormone release may be in the driver seat. That is because hormones are the key players in mood regulation. Take depression as a specific example. Those who suffer from the disease have low levels of serotonin and dopamine. Both dopamine and serotonin are neurotransmitters as well as hormones. Since the hypothalamic-pituitary-adrenal axis relies on serotonin receptors to mediate serotonergic stimulation, it can lead to a chicken or the egg situation. Was the axis damaged first, leading to depression, or was it the axis’ dysfunction that caused dysregulation of important hormones?
Nutrient Deficiency and Mental Illness
The research report Diet and Lifestyle Intervention on “Chronic Moderate to Severe Depression and Anxiety and Other Chronic Conditions,” published in Complementary Therapies in Clinical Practice, found there is a direct correlation between diet and mental illness. The diet in question was plant-based and combined with daily exercise and mindfulness techniques.
Other research has been more specific, finding that certain nutritional deficiencies can lead to the onset of mental illness. One study found that specific nutrients correlated with the onset or exacerbation of mental illness were lacking in many patients suffering from mental health conditions—omega-3 fatty acids, B vitamins, magnesium, zinc, iron, and vitamin D.
The reason behind the onset or worsening of mental illness when the body doesn’t have all its essential vitamins and minerals will differ depending on the vitamin, but it all comes down to the fact that the body is symbiotic. Every process relies on another to run smoothly. To put it into perspective, picture a relay race. Each runner has their job. If one runner falls mid-way to their destination, the entire team is affected.
Healing Through Food
For many with depression or anxiety, the idea of simply changing the food they eat to help them cure or improve their symptoms may sound laughable. Research has shown that there is no joke when it comes to treating depression and anxiety the most natural way possible. No one diet will work for everyone, however, getting all the right nutrients will put the person suffering from the illness on the right track to finding relief.
Evidence has shown that a Mediterranean diet can greatly improve symptoms of anxiety and depression. That could be attributed to the increase in fruits and vegetables, which provide plenty of nutrients, the increased intake of protein-rich legumes, and seafood options that provide omega-3 fatty acids. The DASH diet also showed promise because it reduced inflammatory foods such as sugar, saturated fats, and alcohol.
While diet may not be a complete cure for mental illness, using it to complement existing treatment plans may significantly improve the chance at a full recovery. Eating for good mental health means more than just comforting oneself with food. It’s about fueling the body with what it needs for all the physiological and biological processes to run optimally in the effort to improve psychiatric health.
Byrne ML, Whittle S, Allen NB. The Role of Brain Structure and Function in the Association Between Inflammation and Depressive Symptoms: A Systematic Review. Psychosom Med. 2016 May;78(4):389-400. doi:10.1097/PSY.0000000000000311
Bernard NJ. Inflammation rewires the brain. Nat Rev Rheumatol. 2018 Aug;14(8):442. doi:10.1038/s41584-018-0047-z
Hanley NR, Van de Kar LD. Serotonin and the neuroendocrine regulation of the hypothalamic–pituitary-adrenal axis in health and disease. Vitam Horm. 2003;66:189-255. doi:10.1016/s0083-6729(03)01006-9
Liu YZ, Wang YX, Jiang CL. Inflammation: The Common Pathway of Stress-Related Diseases. Front Hum Neurosci. 2017 Jun 20;11:316. doi:10.3389/fnhum.2017.00316
Rao TS, Asha MR, Ramesh BN, Rao KS. Understanding nutrition, depression and mental illnesses. Indian J Psychiatry. 2008 Apr;50(2):77-82. doi:10.4103/0019-5545.42391
Firth J, Marx W, Dash S, Carney R, Teasdale SB, Solmi M, Stubbs B, Schuch FB, Carvalho AF, Jacka F, Sarris J. The Effects of Dietary Improvement on Symptoms of Depression and Anxiety: A Meta-Analysis of Randomized Controlled Trials. Psychosom Med. 2019 Apr;81(3):265-280. doi:10.1097/PSY.0000000000000673
Jacka, F.N., O’Neil, A., Opie, R. et al. A randomised controlled trial of dietary improvement for adults with major depression (the ‘SMILES’ trial). BMC Med 15, 23 (2017). https://doi.org/10.1186/s12916-017-0791-y
Kiecolt-Glaser JK, Belury MA, Andridge R, Malarkey WB, Glaser R. Omega-3 supplementation lowers inflammation and anxiety in medical students: a randomized controlled trial. Brain Behav Immun. 2011 Nov;25(8):1725-34. doi:10.1016/j.bbi.2011.07.229
Knüppel, A., Shipley, M.J., Llewellyn, C.H. et al. Sugar intake from sweet food and beverages, common mental disorder and depression: prospective findings from the Whitehall II study. Sci Rep 7, 6287 (2017). https://doi.org/10.1038/s41598-017-05649-7