The old saying is that we should eat to live and not live to eat, but what we eat can actually do more than help put our bodies on their feet, and can it change how we feel, or even perceive life?
That’s the question that Nutritional Psychology asks and answers but what exactly is nutritional psychology?
We’re all well aware of how dietary decisions can affect us physically in more than one way; it impacts the risk of chronic diseases, and most medical remedies involve adding something extra to our diet or leaving something out.
Nutritional psychology, on the other hand, is a scientific branch that focuses on how what we eat can impact our brain’s physical health as well as our mental health. In other words, nutritional psychology is the link between why we eat can change how we feel.
What Does Science Have To Say About Nutritional Psychology?
More than thousands of years ago, Hippocrates said, “let thy food be thy medicine and thy medicine be thy food”. Today’s nutritional psychology scientists are keeping his word alive as they have found the many implications of food for our brain and mental health.
● In one four-year prospective cohort study involving over 10,000 university students, it was found that following a balanced Mediterranean diet reduced the risk of developing depression by 42%.
● In another study involving 120 children and adolescents, it was found that consuming fast food, high amounts of sugar and soft drinks led to a higher prevalence of attention-deficit/hyperactivity disorder (ADHD)
It’s important to note that these researches took into account a lot of other potential risk factors as well as excluding any isolated deficiencies, to focus on the diet holistically, which is the main interest of nutritional psychology.
But if it’s not about an isolated nutrient deficiency, then what is the connection between diet and psychology?
How Does the Food You Eat Affect How You Feel?
Contrary to popular belief, our gut biome and feelings are connected in more than one way. Nutritional psychology digs deeper into these many pathways, researching how these different pathways can help us improve our mental health by improving our dietary choices. Here are some of the ways it works:
1. Direct Nervous Connection
The vagus nerve is one of the most important parts of our autonomic nervous system and it’s also the bridge between our brains and our guts, creating a bridge between the two organs.
The autonomic nervous system consists of two parts: The sympathetic and parasympathetic. The one that’s responsible for our stress response is the sympathetic and the one that’s responsible for slowing down is parasympathetic. The Vagus nerve is part of the latter and in our gut, it plays an important role in digestion.
This gut-brain axis plays a role in the connection between mental health and brain disorders also explaining Irritable Bowel Syndrome (IBS). This nerve is the secret behind why digestive problems can put you in a foul mood and why our feelings can be felt in our stomach.
2. Gut Serotonin
Serotonin is one of the most important neurotransmitters in our brain, often called one of our “happy hormones”. It has a role in regulating sleep, our appetite, and inhibiting pain.
Our gut is responsible for producing 95% of the body’s serotonin, explaining one of the major pathways of how our gut and diet can affect our emotions.
The production of serotonin in our gut is not just affected by our dietary choices, but also by our intestinal microbiome, the “gut bacteria”, which takes us to our next point.
3. Gut Bacteria
The gut microbiome plays a role in affecting our mental health and how we feel by interacting with many of the other different pathways.
Firstly, the gut bacteria can trigger an immune response that can put the gut-brain communication at work. Secondly, this bacteria can also communicate with the brain through the vagus nerve. This was proven by research that found cutting the vagus nerve stimulates a chain reaction by affecting the gut bacteria, the brain’s biochemistry, and lastly our behaviors and emotions.
Lastly, gut bacteria plays a vital role in manufacturing the gut’s serotonin by producing an essential short-chain fatty acid called Butyrate. This fatty acid is produced by the gut’s bacteria when we eat plants, explaining how vegetables and fruits don’t just keep your gut happy, but your brain as well!
What Could This Mean?
Nutritional psychology opens the door to a possible treatment for mental health problems and low moods.
Small dietary changes, can make big differences in how we feel.
This was proven by another study where diet adjustments helped a third of psychiatric patients reach remission, in comparison to the control group where only 8% did.
The science is there and nutritional psychology can soon be an option in not just improving how we feel but also solving mental health issues.
● Lachance, Laura, and Drew Ramsey. “Food, mood, and brain health: implications for the modern clinician.” Missouri medicine vol. 112,2 (2015): 111-5.
● Sánchez-Villegas, Almudena et al. “Association of the Mediterranean dietary pattern with the incidence of depression: the Seguimiento Universidad de Navarra/University of Navarra follow-up (SUN) cohort.” Archives of general psychiatry vol. 66,10 (2009): 1090-8. doi:10.1001/archgenpsychiatry.2009.129
● Ríos-Hernández, Alejandra et al. “The Mediterranean Diet and ADHD in Children and Adolescents.” Pediatrics vol. 139,2 (2017): e20162027. doi:10.1542/peds.2016-2027
● Jacka, F.N., O’Neil, A., Opie, R. et al. A randomized controlled trial of dietary improvement for adults with major depression (the ‘SMILES’ trial). BMC Med 15, 23 (2017). https://doi.org/10.1186/s12916-017-0791-y
● Clapp, Megan et al. “Gut microbiota's effect on mental health: The gut-brain axis.” Clinics and practice vol. 7,4 987. 15 Sep. 2017, doi:10.4081/cp.2017.987
● Breit, Sigrid et al. “Vagus Nerve as Modulator of the Brain-Gut Axis in Psychiatric and Inflammatory Disorders.” Frontiers in psychiatry vol. 9 44. 13 Mar. 2018, doi:10.3389/fpsyt.2018.00044
● Butler, Mary I et al. “The Gut Microbiome and Mental Health: What Should We Tell Our Patients?: Le microbiote Intestinal et la Santé Mentale : que Devrions-Nous dire à nos Patients?.” Canadian journal of psychiatry. Revue canadienne de psychiatrie vol. 64,11 (2019): 747-760. doi:10.1177/0706743719874168