Today’s blog post follows up from our previous blog post where we discussed what inflammation is and the differences between acute versus chronic inflammation. Now we are going to discuss how chronic inflammation comes to be and why it is undesirable. Understanding why it happens will hopefully also allow us to better combat it. As a reminder, acute inflammation is the rapid response of the immune system within seconds to days that is intended to protect us from pathogens or to heal recent tissue damage. In contrast, chronic inflammation occurs when our immune system continues to release chemical mediators to elicit inflammation when it is not actually to our body’s advantage. This prolonged inflammation impairs our ability to appropriately heal, keeping us in a state of pain or discomfort.

How does our body’s intricate immune system begin to work against us? Our immune system’s baseline operation is to recognize and act in our defense. Though not fully understood yet, chronic inflammation generally occurs when there is a mismatch between the response from the immune system and what it is reacting to within our environment or in the stimuli of daily life. While in a state of chronic inflammation, the immune system mistakenly triggers an inflammatory response or an overexaggerated response to something seemingly harmless that persists over time. In other words, our immune system puts out an oversized defense against something that isn’t necessarily a harmful pathogen (bacteria or virus) or a real tissue injury (broken bone). An example of this is when we have a stressful day at work, the immune system senses this as a threat to our health and tries to help support the body by releasing proinflammatory molecules like cytokines.

Unfortunately, this prolonged inflammatory response to non-life threatening stimuli comes with consequences. Despite being consistently activated, the immune system becomes overall less efficient leaving us more susceptible to infection and delayed healing. Additionally, the immune system’s defenders can also begin to turn on our own tissues leading to breakdown of cartilage, bone, and other structures in the joint or muscle, and ultimately pain. The longer the slow simmer of chronic inflammation lasts, the greater the increase in risk for various chronic diseases like cancer or cardiovascular disease.

So, what contributes to chronic inflammation occurring? There are a variety of contributing factors to chronic inflammation, some in our control and others beyond our control. There are many health conditions where chronic inflammation is much more prevalent, as well as lifestyle factors that provoke it. Here are some common reasons why chronic inflammation can persist:

1. Chronic infections: Certain types of infections, such as hepatitis C, HIV, and tuberculosis, can cause chronic inflammation as the immune system tries to fight the infection.
2. Autoimmune disorders: In autoimmune disorders, the immune system mistakenly attacks the body’s own tissues, leading to chronic inflammation. Examples of these conditions include rheumatoid arthritis, lupus, and Crohn’s disease.
3. Exposure to environmental toxins: Exposure to pollution, pesticides, and chemicals can cause chronic inflammation in the body. These toxins can damage cells and tissues, leading to an immune response.
4. Poor diet: A diet high in processed foods, sugar, and unhealthy fats can contribute to chronic inflammation in the body.
5. Chronic stress: Chronic stress can trigger the release of stress hormones, which can lead to inflammation.
6. Physical inactivity: A sedentary lifestyle characterized by prolonged periods of physical inactivity can increase the risk of chronic inflammation.
7. Sleep: Studies have shown that lack of sleep or poor quality sleep can increase levels of inflammation in the body, while getting enough sleep can help reduce inflammation.
8. Aging: As we age, our immune system becomes less efficient and can trigger chronic inflammation or make us more prone to inflammation. This can contribute to age-related diseases such as Alzheimer’s, cardiovascular disease, and osteoarthritis.
9. Genetics: Some people may be genetically predisposed to chronic inflammation due to variations in genes that regulate the immune response. These genetic variations such as those involved in the immune system or inflammatory pathways, can increase the risk of chronic inflammation

As you’ve probably come to realize, the immune system is designed to protect us but its response must be kept in check. If allowed to work overtime and run amok, then it stops working in our favor and starts to work against us. Therefore, it is important to identify the signs, understand the underlying causes, and take steps to reduce chronic inflammation, such as adopting an appropriate diet for our needs, getting regular exercise, managing stress, and avoiding exposure to environmental toxins. Look for our future blog posts in this series as we discuss specific steps in managing chronic inflammation!

SOURCES 

1. Richtel M. An Elegant Defense : The Extraordinary New Science of the Immune System : A Tale in Four Lives. William Morrow Paperbacks; 2020.
2. Calder, P. C., Bosco, N., Bourdet-Sicard, R., Capuron, L., Delzenne, N., Dore, J., . . . Visioli, F. (2017). Health relevance of the modification of low grade inflammation in aging (inflammaging) and the role of nutrition. Ageing Research Reviews, 40, 95-119. doi:10.1016/j.arr.2017.09.001
3. Stojanović, M., & de Luka, S. R. (2019). Physical activity and inflammation in chronic diseases. International Journal of Medical Sciences, 16(12), 1494-1509. doi:10.7150/ijms.38636
4. Furman D, Campisi J, Verdin E, et al. Chronic inflammation in the etiology of disease across the life span. Nature News. https://www.nature.com/articles/s41591-019-0675-0. Published December 5, 2019. Accessed March 10, 2023.
5. “Chronic Inflammation.” National Center for Biotechnology Information, U.S. National Library of Medicine, 2021, https://www.ncbi.nlm.nih.gov/books/NBK493173/.