The Sugar-Anxiety Connection You Need To Know About

Anxiety and depression often go hand in hand. For some people, it's more anxiety; for others it's predominantly depression, but they are highly connected and comorbid (occur together). 

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 Nature3 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.

The gut microbiome and its beneficial “bugs” are important for optimal health. Our gut microbiota are malleable and can be negatively or positively affected by our diet choices. High sugar intake can shake up the balance of our gut microbes7, increasing ones tied to inflammation and metabolic dysfunction.

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. 

Another piece of the anxiety puzzle comes into play when we really examine blood sugar. Excess sugar intake contributes to blood sugar spikes and insulin resistance over time. And when your blood sugar is out of whack, it throws off13 your hypothalamic-pituitary-adrenal axis (HPA axis), which is responsible for releasing your stress hormone cortisol14 (think fight-or-flight response).

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. 

Once you have a better understanding of where your health stands, the next step to calming your anxiety is to stop feeding it with sugar. Of course, natural sugars from fruit are fair game and even having a treat here and there is definitely not a bad thing. However, it’s important to be smart about satisfying your sweet tooth by using natural sweeteners instead. Raw honey is one of my favorite options due to its high antioxidant content.