Taming inflammation

Untreated chronic inflammation is the clearest natural experiment we have. Rheumatoid arthritis carried about 47% excess mortality across fifty years of cohorts [2] — mostly heart disease, not joints. Under modern treat-to-target care, that gap has closed to near the general population [11]. 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 [8]. Meanwhile a 72-study meta-analysis found sleep disturbance and long sleep both associated with elevated CRP and IL-6 [9]. 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 [7]. Across 83 randomized trials, exercise training lowered CRP, and it worked even when weight did not change [6]. 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 [12].

In a randomized trial, a Mediterranean diet lowered CRP and IL-6 within three months compared with a low-fat control [13]. A fermented-food diet lowered 19 inflammatory markers in Stanford's randomized microbiome trial [14]. 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 [15]. 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 [16]. 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 [17]. 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 [4], and the periodontology–cardiology consensus treats gum health as cardiovascular prevention [18]. 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 [5].