When sad, eating something sweet may boost mood. In the long term, though, eating sugar-added food regularly has been linked to depression.
Research studies suggest that the gut microbiome, the millions of bacteria, fungi and archaea in the colon, benefits health—particularly brain health—in a variety of ways. Mood/depression is one of the aspects of brain health impacted by eating/gut health.
The key connection between the gut and emotional well-being are the chemicals created when bacteria in the colon process the foods people eat. This processing, the metabolization of the foods by the bacteria, has been linked to activity of the mood hormones serotonin and melatonin within the brain.
Essentials for serotonin
A form of Vitamin E known as α-tocopherol (alpha tocopherol) is one of the chemicals associated with the biosynthesis of serotonin. Researchers at the California Institute of Technology found that α-tocopherol and 15 other “metabolites” are generated from beneficial bacteria working with digested food in the colon.
Foods that work in harmony with the gut microbiome include fish, olive oil, and red wine. Asian and Mediterranean diets promote diversity of gut microbiota, which is a good thing. Additionally, fermented foods and probiotic supplements populate the gut with more beneficial bacteria.
On the other hand, foods that kill healthy microflora, the good bacteria, are red meat, refined sugars and other refined carbohydrates. These foods promote inflammation-causing microflora, leading to problems such as leaky gut, indigestion, heartburn, hormonal imbalance, arterial hardening, and neurodegenerative diseases.
Another study has shown a link between the good bacteria in probiotic supplements and brain activity. Although probiotics help to regulate digestion and immunity, the study participants who took the supplements not only reported fewer symptoms of depression, but their MRIs also showed brain activity in the mood-regulating parts (e.g., the amygdala).
When there are proper levels of serotonin, an individual is happier, alert and satiated. It works with melatonin to regulate the body’s sleeping and waking cycle. When there are higher levels of melatonin, the sleepiness hormone, symptoms of depression can present.
The gut-mood connection of eating is evident not just with hormones carrying messages between nerve cells within the brain, but it is also evident within the cells themselves. The protein BDNF (brain-derived neurotrophic factor) is inside brain cells and is key to cell growth and life. BDNF also promotes the movement of serotonin and melatonin within the brain. When BDNF levels fall, research has shown that depression and Alzheimer’s, among other things, are more likely to occur.
This is just the tip of the iceberg. The intricacies at play among nutrients, gut microbiota, cells, nerves, and hormones seem to be as numerous as the gut bacteria themselves. It’s fascinating to read about the ways they use different foods to positively or negatively impact heart, digestive, and brain health. But all of the reading in the world can’t replace action. May you be healthy and happy.