Biology of Food-Mood Connection
Understanding the biological aspects of nutrition shows how food significantly influences the body’s ability to manage stressors and support mental well-being.
Serotonin is often called the “feel good” neurotransmitter or “feel good” hormone. Serotonin helps regulate your mood, sleep, appetite, and tolerance for pain.
It’s the target of many antidepressant medications. To produce this neurotransmitter, the brain must complete several steps inside the gastrointestinal system that require certain nutrients, including but not limited to vitamin B1, copper, riboflavin, and calcium.
What happens when you don’t get enough of these nutrients? A tug-of-war for nutrients happens. Some systems will lose.
Your intestinal microbiome includes billions of beneficial bacteria that can produce certain vitamins when you don’t get them in your diet. It can create B1 and neurotransmitters like serotonin.
The bacteria in the gut communicate with the brain about what they need from the body to stay healthy. The body tells the gut what it needs to produce more of for various functions.
While the link between gut health and overall health has long been assumed worldwide, researchers are just beginning to understand the importance of gut health to mental health.
A study at Deakin University gathered information about the diets of 213 pregnant women in their third trimester as well as gut microbiome samples. They then followed the new mothers and their children until the age of two. They found that the women with the most diverse intestinal microbes during pregnancy had toddlers who had fewer depressive, anxious, or withdrawn characteristics.
This doesn’t show a direct cause-and-effect relationship. However, all studies are building blocks in our overall understanding.
Combine this study with serotonin’s impact on mood and mental health. This demonstrates the importance of a healthy gut. Consequently, it shows how important it is to maintain a healthy microbiome with nutrition.
Another 2019 study targeted the gut as a means to improve outcomes of patients with mood disorders. This provides further support for the importance of nutrition when therapeutically treating mental illness symptoms.
The bacteria in the gut love fiber, especially the insoluble fiber found in foods like broccoli stems, asparagus, dark leafy greens, beans, whole seeds, and fruit peels. The better fed the microbiome is, the more diverse it becomes.
A diverse microbiome is more adaptable and healthier. A less diverse microbiome can easily be overtaken by harmful bacteria, become inflamed, and lack the necessary components to support mental health.
Immune System Function
Inflammation is a natural tool the immune system uses to fight threats in the body. Certain foods increase inflammation, primarily saturated fat, sugar, and food additives that the body can’t recognize.
Current research suggests that this increased inflammation may explain why those who eat a lot of ultra-processed food also experience brain health challenges like cognitive decline as well as dysfunction in areas of the brain like the hippocampus and amygdala.
The hippocampus helps you manage stress through dopamine production. The amygdala regulates the fight or flight response through adrenaline and epinephrine.
Most of this research has historically looked at how food that may contribute to inflammation can impact people’s physical health. For example, researchers have long known that rampant inflammation increases the risk of developing type 2 diabetes or cardiovascular disease.
However, it’s becoming clearer now that this inflammation also impacts mental health.
One 2010 study found that those with type 1 or 2 diabetes also have abnormalities in their hippocampus, amygdala, and other brain structures that directly impact mental health.
The nervous system includes your brain, spinal cord, and peripheral nerves. This neural network sends and receives messages throughout the body. These communicate instructions for systems to follow.
The efficiency with which nerves transfer these messages depends on the brain’s neuroplasticity—the brain’s ability to create new neural pathways and remove ones that are no longer needed. This allows the body and mind to adapt to changes in the environment or inside the body.
For this reason, a poorly functioning nervous system could lead to or worsen mental health conditions such as anxiety, depression, bipolar disorder, obsessive compulsive disorder, and attention-deficit/hyperactivity disorder, among others.
This complex system depends on nutrients to build proteins and create and maintain nerve fibers. This requires certain amino acids, minerals, fatty acids, and carbohydrates.
For example, omega-3 fatty acids can reduce inflammation in the nervous system and are used therapeutically to help manage many neurodegenerative disorders, such as Alzheimer’s and Parkinson’s diseases. Omega-3s are found in fatty fish like salmon and sardines, as well as plant sources like walnuts, chia, and flax.