Inflammation is an immune system response to damage or injury in the body.
When we sprain our ankle, for example, we feel pain and swelling, discomfort and tenderness. The injured area feels warmer than usual. Those are all symptoms of acute inflammation, where the immune system is sending out highly intense cytokine (a lot of it in the form of TNF-α) signals to recruit all available macrophages (immune cells) to the site of injury so that repairs can be done more quickly.
In the same way, when one catches a cold, TNF-α signalling recruits macrophages to the site of invasion to eliminate the pesky invaders as swiftly as possible. Again, we’re looking at acute inflammation, and the symptoms of intensely high TNF-α levels are mucus hypersecretion (hence runny noses), and a feeling of soreness/inflammation in the throat (much like the soreness in a sprained ankle).
These acute inflammation signals are damped down towards the end of an injury/illness, such that everything can go back to normal. We wouldn’t want to be feeling pain when there shouldn’t be any.
However, what happens when our body is experiencing small pockets of damage consistently?
In oxidative stress situations, for example, our cell mitochondria are producing more free radicals/reactive oxygen species (ROS) than their endogenous glutathione antioxidant levels can handle.
As a result, some of these ROS can leak out and cause damage to other cells or proteins. A mild inflammatory signal is activated for the macrophages to commence repairs. However, oxidative stress consistently generates more ROS than the cells can handle. Hence there will be consistent damage, leading to consistent, or mild chronic inflammation.
Of course, inflammation can come from other sources. In autoimmune diseases, inflammatory signals are generated by the immune system to eliminate healthy cells within the body. Healthy functional cells that the immune system has misdiagnosed as “invaders”. For example, beta cells in the pancreas are destroyed by the immune system in autoimmune (Type 1) diabetes, leading to a weakened insulin signalling and the rest of the body’s cells being unable to take in a “regular” dose of glucose for energy production.
In women, menopause shifts their inflammation balance as well. Estrogen is an anti-inflammatory hormone that is greatly reduced post-menopause, hence post-menopausal women do experience higher levels of inflammation if they do not change up their diets or lifestyles to fit menopause requirements.
We can do blood tests to check TNF-α levels to determine how much inflammation we are experiencing. Or else, we can also check C-reactive protein (CRP) levels. Here’s an Instagram post that I’ve done previously about the CRP levels in our blood, and how it corresponds to the inflammation levels in our body:
A CRP blood concentration of 200 mg/L is considered as acute inflammation and occurs when we have an injury or illness to contend with.
For mild chronic inflammation, we’re looking at CRP concentrations of 10 mg/L or less.
If you don’t want to spend money on blood tests at the hospital, you can look at your own body to see if you are indeed experiencing chronic inflammation or not. The symptoms of one experiencing chronic inflammation are quite obvious:
- Type 2 diabetes, high cholesterol, hypertension (or the metabolic syndrome)
- Osteoporosis (the shift in the inflammation balance for post-menopausal women can be a reason why they are more likely to experience osteoporosis – it ain’t just a calcium intake issue)
- Alzheimer’s/Parkinson’s/dementia (the inflammatory biomolecules can disrupt the blood brain barrier and penetrate into the brain, where they attach themselves to brain cells and programme the brain cells to commit suicide prematurely)
- Osteoarthritis. Macrophages in an inflammatory environment upregulate the production of matrix metalloproteinase (MMP) enzymes. These MMPs digest extracellular matrices, including joint cartilage, leading to a painful degeneration of our joint structures and osteoarthritis over time.
- As I mentioned earlier, autoimmune diseases are a source of inflammation. Someone harbouring an autoimmune disease over a long period of time will be more prone to experiencing chronic inflammation.
These health problems are all linked by chronic inflammation. It’s not surprising, then, that when one contracts one of these problems, the rest will follow when the body’s inflammation balance has gone completely haywire. And of course, there will be more reasons for one to feel symptoms of chronic pain too.