Your brain is the control center of your body, regulating the communication of cells and neurotransmitters, the dispersion of enzymes and hormones and the overall maintenance of your cell health.
The brain is busy, which means it requires a big bulk of your body’s energy supply, using around 60% - 70% of your body’s glucose (its main energy source) to keep up with the demand.
When we start thinking about what provides that energy, the answer is obviously food. The type of food and the quality, quantity and state in which we eat it all has a massive trickle up effect when it comes to the brain and mental health.
One of the more interesting research discoveries in regard to the microbiome is its role in our “second brain”. Your “second brain” lives in your gut and communicates constantly with your first brain (the one in your head) about everything from immune health to neurotransmitter creation.
In fact, up to 90% of your body’s serotonin, a neurotransmitter that’s key to happiness, sleep and appetite, is made by the microbes in your gut. Other beneficial gut microbes do things like increase GABA receptors in the brain, meaning more GABA gets put to use. GABA is vital for mood regulation and a decrease in GABA receptors has been linked to issues like chronic depression.
An intriguing case study to examine how the role of food affects your mental health takes us to Great Britain during WWII
At the time, the country was under rations and food staples, especially bread, were difficult to come by. But something interesting happened when bread left the table: doctors found that many patients institutionalized for psychosis showed improvement in their symptoms.
Once the war ended and bread came back, conditions worsened. But why?
In gluten-sensitive people - roughly 7% of the population or 20 million Americans, many of whom are undiagnosed - gluten can cause symptoms similar to opiates, including brain fog, psychosis, depression and even schizophrenia
That’s because gluten contains opiate-like substances called gluteomorphin and gliadorphin that bind to receptor sites in the brain, hijacking its normal function. Gluten can also damage the lining of the gut, which decreases the ability of the small intestine to absorb the necessary fats and amino acids that are critical for healthy brain function.
Without healthy fuel, the brain can’t do its job effectively, putting you in a bad mood and contributing to conditions like anxiety, depression and fatigue.
How messages get from here to there
The microbiome of the gut communicates with the brain via the vagus nerve, the longest cranial nerve in the body. It runs from your abdomen to your head, crossing the pancreas, liver, kidneys, gallbladder, heart, lungs, neck, ears and tongue as it transmits messages that influence memory, mood and cognition.
It was given the name vagus, or wanderer, precisely because it touches so many parts of the body. It also helps to regulate the parasympathetic nervous system - your rest-and-digest setting - which is crucial for keeping a smile on your face and your stress levels at a manageable level.
When we eat foods that cause inflammation in the body, we’re also inflaming the vagus nerve, which limits its ability to deliver messages effectively. For example, refined sugar is a particularly inflammatory food that’s been shown to contribute to depression due to its detrimental impact on the brain, microbiome and vagus nerve.
Luckily, we can improve the functioning of our the vagus nerve by boosting vagal tone, a fancy way of saying “how the vagus nerve works”.
To stimulate the vagus nerve, you can:
- Gargle with a glass of water
- Do deep breathing exercises
- Sing or chant loudly
- Initiate your gag reflux
- Eat in a relaxed state
Doing any of these things before eating prompts the vagus nerve to promote the release of stomach acid, a necessary part of proper digestion that has a positive domino effect on the rest of the digestive process.
In terms of eating for optimal brain-mood health, make sure your diet consists of plenty of microbe-boosting foods, including prebiotics like garlic, onions, jicama, Jerusalem artichoke and chicory and probiotics such as raw, fermented sauerkraut, full-fat kefir or yogurt, kombucha, kimchi, miso and natto.
And while a good diet is essential when we’re dealing with mental health and optimal cognitive function, it’s likely not sufficient on its own. Unfortunately, the quality of our soils produces foods that aren’t as nutrient-dense as they once were, so it’s also a good idea to add pre- and probiotic supplements to your daily routine.
These days, an exciting time has dawned, as probiotics are now being called psycho-biotics. People are starting to discover that these microorganisms are quite literally what’s feeding and producing the brain chemicals that help us to thrive. To me, this information is extremely empowering because it paves the way for us to put our mental health and our mood squarely in our own control.