This week’s blog series is all about the role inflammation and inflammatory foods have on our body as a whole - and I’m sure you’re not surprised by now, how it effects our brain, our mood, and our overall mental well-being.
When Inflammation Becomes Chronic:
Research has shown an inarguable link between gut dysbiosis and the brain through inflammatory markers in the blood (inflammation). 1 As we have learned high levels of inflammation signals to us that our immune system is on alert which can increase the risk of developing depression. Seems logical that the higher the level of inflammatory markers the more our bodily system can spiral into more severe depression. These inflammatory markers could possibly come from one dietary source or a collection of offenders that effect the brain due to their impact on our immune system and the associated stress response.
With the brain imbalance model of depression exposed, the science of psychoneuroimmunology has emerged. This approach takes us away from pointing at ‘bad’ genes and a one pill for all and looks at the interconnectedness of the gut, brain, and our immune system as having a role in mental health.
Lipo means fat, poly means many, and saccharides are sugars - LPS is a combination of fat and sugars found on the outer membrane of certain gut bacteria. LPS can represent up to 50 to 70 percent of our gut microbiome. 2 LPS works to protect these bacteria so they are not digested. LPS is not intended to leave the stomach, but if the tight junctions in the gut lining are compromised they can sneak past and enter the blood stream creating an inflammatory response. LPS can travel to the brain through the blood-brain barrier bringing along with it a pro-inflammatory response. 2 Science is increasingly learning that inflammatory markers correlate with depression and LPS increases the production of these markers.
We know inflammation is a necessary part of our body’s defense mechanism, but as we are learning when the triggers become chronic the effects can be harmful. Inflammatory depression is the activation of the immune response with stress serving to further spark depressive behavior through inflammatory cytokines (remember cytokines are messengers of our immune system).
When cytokines are elevated and as these pathways are constantly activated our body’s begin to recognize them as familiar. In cases of depression and other mental health conditions research has reported that our white blood cells express pro-inflammatory genes that generate the secretion of cytokines. 3 The increase of cytokines leads to a decrease in cortisol sensitivity. 4 Cortisol is our major stress hormone and serves as a barrier to inflammation - this feedback loop enables the cycle of inflammation. And as we discussed in blog # 2 once triggered, inflammation transfers information through the nervous system. During an inflammatory response cells in the brain are activated that produce enzymes that have been shown to have a chain of reactions that have been linked to symptoms of anxiety, agitation, and depression. 5
When we are feeling depressed we can’t feel inflammation in our brain like we would from a bump or a bruise due to the lack of pain receptors in our brain. 6
Inflammation and Mental Health Conditions
Inflammation is the primary cause of chronic illness
70% of our immune system is in our gut
We outsource countless bodily functions to our beneficial microbial communities
Microorganisms outnumber our human cells 10:1
The gut is the gatekeeper of inflammatory response
Depression is far more likely to be a symptom of chronic illness due in part to inflammation stemmed from an imbalance in our gut. Inflammation has a significant role in depression and science is learning more and more that depression is a symptom that something is off balance in the body. It is our body’s way of telling us something is ‘off’. Reminding us that,“mental health is a manifestation of all that your body is experiencing and your minds’ interpretation of its own safety and power.”
Check back next week when we look into another system in our body that plays an integral role in our mental health - The Endocrine System. See you then!
Clapp M, Aurora N, Herrera L, Bhatia M, Wilen E, Wakefield S. Gut microbiota’s effect on mental health: The gut-brain axis. Clin Pract. 2017; vol 7(4): 987 doi: 10.4081/cp.2017.987.
Brogan K MD, Loberg K. A Mind of Your Own. Thorsons. 2016.
Howren MB, Lamkin DM, Suls J. Association of depression with C-reactive protein, IL-1 and IL-6: A Meta-Analysis. Psychosomatic Medicine. 2009; vol 71(2): 171-86. 10.1097/PSY.0b013e3181907c1b.
Carvalho LA, Bergen V, Sumaski L, Wijkuijs J, Hoogendijk WJ, Drexhage HA. Inflammatory activation is associated with a reduced glucocorticoid receptor alpha/beta expression ratio in monocytes of inpatients with melancholic major depression disorder. Translational Psychiatry. 2014. https://www.nature.com/articles/tp2013118.
Steiner J, Walter M, Gos T, Guillemin GJ, Berstein HG, Samyai Z, el al. Severe depression is associated with increased microbial quinolinic acid in subregions of the anterior cingulate gyrus: Evidence for an immune-modulated glutamatergic neurotransmission? J Neuroinflammation. 2011; vol 8: 94. 10.1186/1742-2094-8-94.
Lui Y, Wang Y, Jiang C. Inflammation: The Common Pathway of Stress-Related Diseases. Front Hum Neurosci. 2017; 11: 316. 10.3389/fnhum.2017.00316.