Inflammation of the body is a normal reaction of the immune system when there is a threat to its integrity. But it can also get carried away and become a problem. Explanations.
- Chronic inflammation is the cause of many diseases such as diabetes, asthma, obesity, certain cancers, depression, Alzheimer’s disease, osteoarthritis, inflammatory bowel disease, psoriasis, rheumatoid arthritis or multiple sclerosis.
- Stress and diet, as well as genetic and environmental factors, have been shown to regulate inflammation in one way or another. A healthy lifestyle would thus ward off the risk of harmful chronic inflammation.
When our body fights an infection, we get a fever. If we suffer from arthritis, our joints will be painful. If a bee stings our hand, it will swell and stiffen. What do these three reactions have in common? These are all manifestations of inflammation that occur in the body, and form the basis of a normal physiological response. In an article published in the independent media The Conversationimmunologists Prakash Nagarkatti and Mitzi Nagarkatti, from the University of South Carolina (USA), explain how inflammation is necessary for the proper functioning of our body.
Inflammation as an immune response
Broadly speaking, the term inflammation refers to all immune system reactions that occur when the body is trying to fight infections, recover from physical injury, eliminate toxic molecules, or even fight against an autoimmune disease. There are five main physical signs of acute inflammation: warmth, pain, redness, swelling, and loss of function.
Take a bee sting. After detecting the toxins, bacteria and physical damage caused by the bite, the immune system deploys various types of immune cells to the site of the bite: some will produce antibodies that will neutralize pathogens or cytokines that will repair tissues, others will kill any cell infected with the virus, etc. But, as in any attack, inflammation is accompanied by collateral damage: healthy cells will be destroyed during the process, blood vessels may leak… This is the reason why swelling, redness and pain where you were stung. After a few days, your body will neutralize the poison from the bite, eliminate any bacteria that got in, and heal any damaged tissue. It’s the same logic for everything, even a flu shot.
Inflammation as a possible cause of disease
If inflammation is a saving reaction of our body, it can however be problematic when it becomes chronic or occurs for the wrong reasons. Allergies, for example, develop when the immune system mistakenly identifies harmless substances, such as peanuts or pollen, as dangerous. The reaction can be minor, like itchy skin, or dangerous, especially if someone’s throat closes up.
Chronic inflammation, on the other hand, damages tissues over time and can lead to many non-infectious clinical disorders, starting with cardiovascular and neurodegenerative diseases, obesity, diabetes and certain types of cancer. Sometimes the immune system may even mistake its own organs and tissues for “invaders”, leading to inflammation throughout the body or in specific areas. This is what causes the symptoms of autoimmune diseases such as lupus, arthritis or Crohn’s disease.
