Inflammation-Immunity Connection?

2 min

The human immune system is a remarkable defense mechanism. By recognizing what is “self” and what is not, it fends off bacteria, viruses, and other invaders that can disrupt the body’s balance of health. We can tell that it is activated after an acute injury, when local redness, heat, swelling, and pain are signs that the immune system is working to heal. Likewise, the fever and swollen glands that often accompany illness are signs that the immune system is performing as it should. When inflammation becomes chronic, however, the immune system malfunctions – and the result is a process that injures rather than heals.

In an acute injury or infection, white blood cells rush to the rescue, quickly followed by monocytes and macrophages, which release inflammatory compounds called cytokines to defend the body and restore balance. Once the acute situation is resolved, the cytokines recede. When a state of chronic inflammation exists, however, those cytokines continue to do their work – and by continuing to produce inflammation they compound the problem. (Even in acute situations the process can go awry when an overly aggressive release of cytokines leads to a “cytokine storm,” the sequence of physiologic events that may have played a role in some Covid-19 deaths.)

Keeping the immune system in check, to be called on only when needed, is one good reason to avoid chronic inflammation. There are many others, including its association with the development of type 2 diabetes, cardiovascular disease, dementia, and certain cancers.

We know that inflammation increases as we age – a condition that has been called “inflammaging” – and that immunity wanes then as well. The elderly are more vulnerable to infection than are younger people, and vaccines that work by triggering the immune system tend to be less effective in those over 60. It’s not just older adults who are at risk, however. The typical American diet, combined with a sedentary lifestyle, can facilitate a state of chronic inflammation even in younger individuals.

Although we can’t control aging, we can take steps to live more healthfully and keep inflammation in check. Exercising, getting enough sleep, and eating an anti-inflammatory diet are key strategies.

See also: Dr. Weil’s Anti-Inflammatory Food Pyramid

Andrew Weil, M.D.

Sources
Goldberg EL, Shaw AC, Montgomery RR. How Inflammation Blunts Innate Immunity in Aging. Interdiscip Top Gerontol Geriatr. 2020;43:1-17. doi: 10.1159/000504480. Epub 2020 Apr 9. PMID: 32294641; PMCID: PMC8063508. pubmed.ncbi.nlm.nih/32294641/

Christ A, Lauterbach M, Latz E. Western Diet and the Immune System: An Inflammatory Connection. Immunity. 2019 Nov 19;51(5):794-811. doi: 10.1016/j.immuni.2019.09.020. PMID: 31747581. pubmed.ncbi.nlm.nih/31747581/

Kany S, Vollrath JT, Relja B. Cytokines in Inflammatory Disease. Int J Mol Sci. 2019 Nov 28;20(23):6008. doi: 10.3390/ijms20236008. PMID: 31795299; PMCID: PMC6929211. ncbi.nlm.nih/pmc/articles/PMC6929211/