Moral of the story: pay attention, because your body may be telling you something
Joint pain and muscle aches are a fact of life—chances are you will experience one or the other at some point in your life. In fact, up to 70% of people experience non-specific back pain in their lifetime. So, chances are, if you haven’t experienced this yet, you’re very likely to experience it soon. The thing is, we tend to shrug off these aches and pains as a symptom of getting older, but on a deeper level, it’s actually your body informing you about inflammation in the body.
While inflammation is typically a good thing in the face of injury and wound healing, it can also cause damage to many bodily systems if left uncontrolled.
As such, long-term increases in inflammation have been linked to medical problems like stroke, Alzheimer's disease, allergic asthma, chronic kidney disease, chronic obstructive pulmonary disease, chronic respiratory diseases, inflammatory bowel disease, heart diseases, cancer, obesity, diabetes, and a variety of autoimmune diseases.
It is important to understand the effects of inflammation, and to listen to your body, because it may be telling you about its inflammatory state.
What is Inflammation?
Thinking back to the early middle to high school days, you may remember talking about the immune system, and how its primary purpose is to signal the body to fight off invading bacterial and viral pathogens.
What you likely didn’t learn about, are the many ways the immune system is activated. For example, pathogen-associated molecular patterns, or PAMPs are agents associated with infection: these are your typical viral and bacterial organisms.
On the other hand, there are danger-associated molecular patterns, or DAMPs, which may be a term you have never heard of.
DAMPs are things in the intracellular and extracellular environment that trigger the immune response, but are not pathogenic (i.e., not viruses or bacteria). Examples of DAMPs are reactive oxygen species (ROS) and free radicals, improperly folded proteins, increased intracellular calcium, or low glucose levels in the cell. All of these can trigger an immune response, which increases inflammatory compounds in the body that are meant to protect the cellular environment against the strain and stress caused by these damaging events.
Inflammation protects our bodies from damaging stimuli, whether these stimuli are external in the environment or internal within our bodies.
What Happens When We Experience Inflammation?
As you may expect, inflammation is highly coordinated by the immune system.
When you experience a cut or scrape on the skin, chemical signals called cytokines are released by local immune cells like macrophages and neutrophils. Cytokines are small proteins of the immune system that enhance the immune response by recruiting more cytokines and other inflammatory mediators like acute-phase proteins.
All of this is simply to promote blood clotting and repair of the tissue that was cut open. The tender feeling you get with a cut or bruise is a signal that inflammation is active in that region of the body. The area may also begin to feel warm and appear red—these are all signs of local inflammation at work.
So, Is Inflammation Good or Bad?
Well, long story short, it can be both.
The body requires inflammation because, as mentioned, it is an essential process that protects the body from foreign substances and pathogens, and helps the body repair itself. The body responds to these events through acute inflammation—a rapid increase in inflammatory mediators like cytokines and acute-phase proteins, followed by a rapid decline in these mediators by anti-inflammatory compounds like interleukin-10 and stress hormones (i.e., cortisol).
Interestingly, the body also relies on constitutive levels of inflammatory mediators even in the absence of an inflammatory response. For instance, interleukin (IL)-6, tumor necrosis factor (TNF)-α, and interleukin (IL)-1β are all cytokines important in various bodily functions, including the stress response, cognition, exercise, and mood regulation.
But, when inflammation gets out of hand and begins to go awry, things can turn for the worse pretty quickly if left unchecked.
Constant activation of the inflammatory response via frequent infections or by reducing the body’s ability to turn off the immune response (which can result from chronic stress) can both cause a gradual shift away from the delicate balance between anti- and pro-inflammatory processes in the body. As a result, a low-grade, pro-inflammatory state can arise, which is often a cause for concern and is thought to be the origin of many age-related diseases.
What Are the Effects of Oxidative Stress as It Relates to Inflammation?
Think back to when you exercised last. After that last bicep curl, that final step of a walk, or the last stair climbed on the stepper, do you remember feeling a bit warm? If you were doing bicep curls, did you stop to feel the warmth given off by the bicep muscle? These are instances where inflammation is active.
You see, exercise causes the muscles to work and burn energy. The result of the chemical reactions required to burn the energy necessary to contract muscle tissue produces free radicals in the cellular environment. While heat is a direct byproduct of these chemical reactions, the unchecked buildup of free radicals is also a cause of heat dissipation, which primarily results from oxidative stress-induced inflammation.
This is why recovery is important.
Recovery allows muscle to remove free radicals, and overworking causes a buildup of these free radicals. The buildup of free radicals in any cell is a source of inflammation, and this goes back to the idea of DAMPs. Free radicals and other reactive oxygen species cause a molecular pattern of events in the cell that trigger a large protein complex called the inflammasome. This complex is responsible for producing inflammatory proteins like IL-1β and IL-18, which are both signals of cellular stress. Prolonged activation of the inflammasome can weaken cellular health and has even been linked to deficits in mood and the ability to process and sense rewards.
Aside from natural processes that cause inflammation via free radicals, the inflammatory response can directly increase oxidative stress by increasing metabolic activity of cells. These free radicals can impair the normal function of proteins and membranes of the cell, which can result in cellular damage and even cell death (i.e., apoptosis).
It’s suggested that ensuring a good antioxidant status in the body, either through food or supplements, may be a suitable approach in lowering the oxidative stress caused by inflammation.
Why Does Chronic Inflammation Occur?
As mentioned, chronic inflammation is a continuous bodily state where the regular acute inflammatory response becomes persistently imbalanced.
In other words, chronic inflammation is when the body’s ability to reduce inflammation becomes weakened. As a result, compounds related to the active inflammatory response like pro-inflammatory cytokines gradually increase and circulate in the blood.
Other events in the body that control inflammation, like the stress response, also become weakened. The primary stress hormone, cortisol, is anti-inflammatory and helps suppress the immune system. But the repeated exposure to stress and/or frequent activation of the immune system, combined with the subsequent release of pro-inflammatory molecules, can weaken the stress response, and further weaken the body’s ability to reduce inflammation.
It’s basically like a vicious cycle.
You can think about the development of chronic inflammation as a dam that holds back a large body of water. The water being held back is the combination of pro-inflammatory molecules while the dam itself is a combination of anti-inflammatory compounds.
The dam regulates the flow of water by keeping a delicate balance between the water being held back and the amount of water permitted to travel to the body of water on the other side.
Similarly, anti-inflammatory compounds regulate the amount of pro-inflammatory activity, allowing only a necessary level of inflammatory compounds to circulate and safeguard the cells and tissues, and to engage in their other roles throughout the body (as mentioned earlier).
But, if there is frequent heavy rainfall or the dam isn’t updated regularly to maintain its integrity and strength, the water being held back may overpower the dam and burst through, which can cause erosion to shorelines and lead to potential flooding.
Again, this is similar to how chronic inflammation works. Over time, if you experience long periods of stress without taking care of your body and immune system, the cumulative effects of this stress and strain can buildup and breakdown the anti-inflammatory mechanisms of the body, leading to increased inflammation and heavy wear and tear on the body. What’s worse, because there is nothing controlling the inflammation (i.e., there is no dam controlling the flow of water), the pro-inflammatory molecules can flow freely and persistently wreak havoc on the bodily environment.
As suggested, this continuous damage caused by chronic inflammation is linked to many health conditions, especially those associated with aging.
In The End…
Only you can tell when something is off. Again, listen to your body and learn the signs and symptoms of inflammation. Improving your antioxidant status and letting your body recover are suitable ways you can help your body fight off the negative impact of inflammation and reduce your chances of developing chronic inflammation over time.
1. Back pain prevalence:
3. Effects of inflammation:
4. Inflammasome/unfolded protein response, inflammation, mood & reward:
5. Inflammation effects on motor and motivation:
6. Danger-associated molecular patterns (DAMPs):
7. Autoimmune Diseases: Types, Symptoms, Causes, and More: https://www.healthline.com/health/autoimmune-disorders
8. Everything You Need to Know about Inflammation:
9. Free Radicals, Antioxidants in Disease and Health. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3614697
10. Free Radicals, Antioxidants and Functional Foods: Impact on Human Health. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3249911
11. Oxidative Stress Inhibits Distant Metastasis by Human Melanoma Cells. https://www.nature.com/articles/nature15726
12. Antioxidants, Inflammation, and Chronic Inflammation
13. Could a cold teach your body to fight COVID-19? https://magazine.medlineplus.gov/article/could-a-cold-teach-your-body-to-fight-covid-19