When the COVID-19 pandemic overtook our lives and forced the world into lockdown, mental health took a back seat to physical health. But with recent studies showing a staggering increase in stress, anxiety and other more acute mental health disorders, our approach to whole person health has never been more important. And research suggests that the link between physical health and mental health is much closer than we think. Believe it or not, what you put into your stomach has a significant impact on your mood. Research shows that what we eat actually affects our mental health. Think about it – at one point or another, we’ve all felt “butterflies” in our stomachs as a response to being nervous. Or maybe a wave of nausea during a time of stress. We talk about “gut instinct” as a key driver of intuitive decision making. It’s clear that our mood can impact our gut, so why wouldn’t our gut be able to impact our mood? And what has the biggest impact on gut health? Diet. Better quality diets are associated with better mental health outcomes, just as poor-quality diets are associated with a greater risk for mental health disorders such as depression and anxiety. So, how is it all connected?
Your gastrointestinal (GI) tract contains a collection of microorganisms known as the gut microbiome, and this microbiome is responsible for producing about 95% of the body’s serotonin, according to a 2015 study by O’Mahony et al. Serotonin is a neurotransmitter that helps regulate sleep and appetite, mediate moods, and inhibit pain. It’s easy to see why serotonin is vitally important in regards to mental health. Production of serotonin in the GI tract is highly influenced by the microbiome, which is in turn impacted by the food we put into our bodies. This is known as the brain-gut axis concept, which is a “bidirectional communication network between the brain and the gut”, with serotonin being the key signaling molecule. Basically, what this means is that our brain and our gut are closely connected. The food we ingest impacts the health of our gut microbiome, which in turn influences serotonin production, which affects our mood.
By now, you might be thinking “okay, well what can I do to improve my gut health?” The best thing you can do is move away from the typical “Western” diet, which tends to be high in fats and contain processed foods, refined sugars, and dairy items. “Traditional diets” such as Japanese and Mediterranean diets, on the other hand, show a 25-35% lower risk of depression and other mood disorders, and even show preventive effects of depressive disorders. These traditional diets include high amounts of fruits, vegetables, grains, and fish, and minimal lean meats and dairy. Here are some evidence-based examples of foods that promote better mental health:
Omega-3 Fatty Acids – from foods such as wild coldwater fish (salmon, mackerel), flaxseed and walnuts, can reduce symptoms of severe mental disorders, including schizophrenia, depression and ADHD.
Whole grains – from whole wheat bread, oats, wild rice and barley, release glucose slowly and provide a steady course of energy for the brain.
Lean protein – such as fish, turkey, chicken, eggs and beans can positively affect mood through the production of serotonin.
Leafy greens* – such as spinach, kale, arugula and broccoli are high in folic acid as well as other minerals that can positively affect mental health.
Fermented foods – including kimchi, tempeh and some pickled vegetables contain healthy bacteria in the form of probiotics, which can improve gut health and reduce stress and anxiety.
*If you need some help getting your ‘greens’ in, try the following green powders – you can add them to shakes or juices to get your daily dosage in.
If this all sounds a bit overwhelming, try this tip from Dr. Eva Selhub of Harvard Medical School: try cutting out processed foods and sugars and increasing your fruit and veggie intake for two or three weeks. Eat as “clean” as you can. Pay close attention to how you feel, and see how it impacts your mood. Then, slowly introduce foods back into your diet and see how those make you feel in the following days. You might be surprised with how much better you feel, both physically and mentally!