The 9 things that matter most for taming inflammation

Untreated chronic inflammation is the clearest natural experiment we have. Rheumatoid arthritis carried about 47% excess mortality across fifty years of cohorts (Dadoun, Joint Bone Spine 2013) — mostly heart disease, not joints. Under modern treat-to-target care, that gap has closed to near the general population (Lacaille, Ann Rheum Dis 2017). The disease did not get milder; the inflammation got treated.

Growth hormone — the body's main repair signal in adults — is secreted almost entirely during slow-wave sleep, and both decline together with age (Van Cauter, JAMA 2000). Meanwhile a 72-study meta-analysis found sleep disturbance and long sleep both associated with elevated CRP and IL-6 (Irwin, Biol Psychiatry 2016). Skimp on deep sleep and you get more inflammatory signaling and less of the hormone that repairs the damage — the same bad trade, twice.

Exercise is an inflammatory stressor that ends up anti-inflammatory: each session releases muscle-derived IL-6 that triggers a counter-regulatory cascade, and with repetition baseline inflammation falls (Gleeson, Nat Rev Immunol 2011). Across 83 randomized trials, exercise training lowered CRP, and it worked even when weight did not change (Fedewa, Br J Sports Med 2017). The dose matters: regular and moderate beats occasional and punishing.

Belly-deep visceral fat is not storage; it is an endocrine organ that secretes IL-6 and TNF around the clock, which is why CRP tracks waist size so closely. Weight loss lowers CRP almost linearly — roughly 0.13 mg/L for every kilogram lost, across 73 studies, by diet or surgery alike (Selvin, Arch Intern Med 2007).

In a randomized trial, a Mediterranean diet lowered CRP and IL-6 within three months compared with a low-fat control (Estruch, Ann Intern Med 2006). A fermented-food diet lowered 19 inflammatory markers in Stanford's randomized microbiome trial (Wastyk, Cell 2021). Fiber feeds gut bacteria that produce anti-inflammatory short-chain fatty acids; sugar and ultra-processed food push the other way.

Smoking keeps the lungs and vessels in a state of continuous inflammatory injury: smokers run measurably higher CRP, IL-6, and white-cell counts, scaling with pack-years, and the elevation persists for years after quitting before slowly normalizing (McEvoy, Arterioscler Thromb Vasc Biol 2015). It is the largest voluntary inflammatory exposure most people ever take on.

Chronic psychological stress keeps cortisol and inflammatory signaling elevated — the pathway mapped from stress to cardiovascular disease runs directly through inflammation (Kivimäki & Steptoe, Nat Rev Cardiol 2018). The link runs both ways into the mind, too: about one in four people with depression shows low-grade systemic inflammation on a blood test (Osimo, Psychol Med 2019). Depression is not "just" psychological; part of it is inflammatory biology.

Periodontitis is a chronic infection that leaks bacteria and inflammatory mediators into circulation daily. Meta-analysis puts it at roughly 24% higher coronary heart disease risk, independent of the usual confounders (Humphrey, J Gen Intern Med 2008), and the periodontology–cardiology consensus treats gum health as cardiovascular prevention (Sanz, J Clin Periodontol 2020). It is the most ignored source of lifelong low-grade inflammation.

Every infection is an inflammatory event, and some leave the immune system persistently activated — long COVID made visible what post-viral syndromes have done quietly for decades. The arithmetic favors vaccines strongly: a vaccine is a small, controlled inflammatory exposure that prevents the massive, uncontrolled one from the disease itself, which is why vaccination in older adults tracks with fewer heart attacks and less dementia, not more (Ferrucci & Fabbri, Nat Rev Cardiol 2018).