Specialized pro-resolving mediators I – How does inflammation work?

 
 
 

Inflammation is part of the body’s immune response to an infection or injury. When something harmful or irritating affects a part of our body, there is a biological response to try to remove it; the signs of inflammation (redness, swelling, heat, and pain) show that the body is trying to heal itself. These signs occur as a result of an increase in blood flow, which allows that cells and molecules of the immune system arrive at the infected or lesioned tissue and begin the healing process of damaged tissue; they have a lot of work to do: to kill the pathogens (virus, bacterium, or other microorganisms), to make them disappear completely (a group of cells named macrophages will eat them when they are dead!), to clean the infected tissue, and repair it. These actions of the immune system must be ordered and controlled in a normal, immune response. Inflammation is part of the healing process.

Although inflammation is a normal response, when it occurs in an uncontrolled or inappropriate manner, excessive damage to tissues can be produced. Acute inflammation starts and becomes severe rapidly, for example: a cut on the skin, an infected ingrown toenail, and an acute appendicitis. If it is not resolved, chronic inflammation (long-term inflammation) appears. Thus, an unresolved inflammatory response is likely to be involved in the development of several diseases, for example: asthma, some cancers, rheumatoid arthritis, atherosclerosis, periodontitis, etc. An overactive immune system reaction can cause chronic inflammation. So, controlling inflammation is crucial to human health.

Nutrition influences inflammatory processes and can help to reduce chronic diseases risk. The Western diet, rich in fat and simple sugars but often poor in important nutrients, is linked to the increase of diseases with immunological components, for example: allergies, atopic dermatitis and obesity.

Long-chain omega-3 polyunsaturated fatty acids (mainly EPA and DHA) decrease the production of inflammatory molecules and are precursors of specialized pro-resolving mediators.

But we will leave that for next post.

 

Bibliography:

Calder PC. n-3 Polyunsaturated fatty acids, inflammation, and inflammatory diseases. Am J Clin Nutr. 2006;83(suppl):1505S–19S. http://ajcn.nutrition.org/content/83/6/S1505.long

Medical News Today. Inflammation: Causes, Symptoms and Treatment. Last updated: Wed 16 September 2015. http://www.medicalnewstoday.com/articles/248423.php

Minihane AM, Vinoy S, Russell WR et al. Low-grade inflammation, diet composition and health: current research evidence and its translation. Br J Nutr. 2015 Oct 14;114(7):999-1012. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4579563/