Chronic low-grade inflammation
A persistent, mild elevation of inflammatory signals in the blood that tends to rise with age.
Chronic low grade inflammation is a persistent, mild elevation of inflammatory signalling without an infection or injury to explain it. It is not the redness and swelling of acute inflammation; it is a background hum measurable only in blood markers such as hs-CRP.
It matters because it tracks with most of the major chronic diseases: cardiovascular disease, type 2 diabetes, some cancers, and cognitive decline. It rises with age, a pattern often called inflammaging, and it is one of the mechanisms proposed to link ageing with the diseases of ageing.
Its main drivers are identifiable and largely modifiable. Excess visceral fat is a major one, since expanded fat tissue releases inflammatory signals. Physical inactivity, smoking, poor sleep, chronic psychological stress, periodontal disease and a diet low in fibre and unsaturated fat all contribute.
Exercise has an interesting dual role. Each session produces an acute inflammatory response, and regular training lowers baseline inflammatory markers over months, which is the same hormetic pattern seen throughout exercise physiology.
Measuring it is cruder than the concept suggests. hs-CRP is the practical marker and it is non-specific, rising with any recent infection, injury or hard training session, which is why a single raised value means retest rather than act.
The anti-inflammatory supplement category vastly outruns its evidence. Effects on markers are small and inconsistent, and effects on outcomes are largely unstudied, which is a poor basis for a shelf of products.
In practice, the interventions with real effect sizes are losing excess visceral fat, exercising regularly, sleeping, stopping smoking and eating enough fibre.