Patients with anxiety and/or depression are often prescribed selective serotonin reuptake inhibitor (SSRI) medications, which prevent the reuptake of serotonin, making more serotonin available for your brain. When these medications were originally developed over 30 years ago, it was believed that anxiety and depression were caused by low levels of serotonin1, the “feel good hormone.” It turns out that the mechanisms aren’t quite so binary. Serotonin and its role in brain function are much more nuanced2 than originally thought (and still being worked out). In fact just a few years ago, a study in the journal 3Nature3 revealed a new anxiety-regulating circuit in the brains of mice. SSRIs (which increase serotonin) activated this novel circuit and produced anxiety (kind of counterproductive, right?). Well, that same paradox has been reported in humans, with certain patients suffering from worse anxiety when taking SSRIs, especially the first few weeks. Guess what also raises serotonin levels? Sugar. From studies in rodents, we know that lower serotonin levels in the brain stimulate sugar craving4. But long-term intake of a high-sugar diet desensitizes serotonin receptors5 (meaning more sugar may be needed to satisfy the craving). In humans, higher sugar intake from sweet foods and beverages significantly increases one’s odds of having a mental health disorder6, making the case for lower intake of sugar to support psychological health. While more research is needed, it’s possible that if you struggle with anxiety and/or depression, by eating added sugars, you’re contributing to the neurochemical reaction of these mental health pathways and further perpetuating the issue. Maybe Mary Poppins wasn’t too far off when she sang “a spoonful of sugar helps the medicine go down.” So you can either choose to feed good bacteria or bad bacteria—and sugar appears to feed bad bacteria and can contribute to yeast overgrowths like Candida. When bad bacteria predominate, it creates an imbalance that can lead to chronic systemic inflammation8 (which is linked to many diseases, including anxiety and depression9). Even if you don’t have digestive symptoms, you can still have underlying digestive problems—they may just be manifesting themselves in different areas of your body, like your brain or nervous system. In fact, supporting gut microbiota through probiotics and dietary interventions (e.g., low FODMAP diet) has been shown to improve anxiety10. Did you know that your gut and brain are connected11 from the very start? The two organs develop from the exact same fetal tissue in the womb and continue to communicate together your whole life through the vagus nerve and the gut-brain axis. When you have chronic inflammation, it can lead to damage of your protective blood-brain barrier and what us functional medicine doctors like to call “leaky brain.” And because your brain’s immune system is working even harder to fight off invaders due to barrier destruction, it can lead to an inflammatory-autoimmune response. So it’s really no surprise that anxiety and depression are more common in patients with autoimmune diseases12 due to the inflammatory effect on the central nervous system. If you’re constantly throwing off your adrenals with sugar, you’ll never really calm down which can further perpetuate the feelings of anxiety. If you want your HPA axis to function properly, keeping your blood sugar levels in check is paramount. Plus, when your blood sugar levels are off, it can increase those “hangry” feelings; you’ll find yourself wanting sweet and salty foods to feel satisfied. But that’s the problem: You never get off the hamster wheel that is blood sugar imbalance and anxiety. A diet high in sugar and high-glucose foods (i.e., high glycemic index) can play a direct role15 in the development and progression of anxiety and depression. So making smart choices about sugar and carb intake can support mental health (and overall health). Hop on over to my sweetener guide to find the perfect sweetener for you! A cutting-edge nutrition deep dive taught by 20+ top health & wellness experts
