Inflammaging: Chronic Inflammation and Aging

What the word means

Inflammation is the body's normal response to injury and infection. Inflammaging is a proposed term for the chronic, low-grade, sterile (not caused by an active infection) inflammation that tends to rise with age. A 2018 review describes it as contributing to age-related diseases, and proposes that stimuli such as pathogens, cell debris, excess nutrients and gut microbiota may sustain it. [1] It is a research concept, not a diagnosis, and no routine test labels a person as "having inflammaging". This page is information only. Evidence labels are explained in How We Label Evidence in Longevity Research.

What is known

Association. A review in Nature Reviews Cardiology says most older people develop elevated blood inflammatory markers, which carry higher susceptibility to chronic illness, disability, frailty and premature death. [2] A large meta-analysis of 160,309 people without vascular disease from 54 prospective studies found higher C-reactive protein (CRP, a blood marker of inflammation) was associated with higher risk of coronary heart disease, ischaemic stroke, vascular mortality and non-vascular mortality. [3] The authors noted that associations with vascular disease depended considerably on conventional risk factors and other inflammation markers, and that the relevance of CRP to so many disorders is unclear. [3] Label: association, not proof of cause (observational).

Possible causes of the rise. The cardiology review lists genetic susceptibility, central obesity, increased gut permeability, changes to gut microbiota, cellular senescence, inflammasome activation, mitochondrial oxidative stress, immune dysregulation and chronic infection as candidates. [2] A 2019 Nature Medicine perspective names infections, physical inactivity, poor diet, environmental toxicants and psychological stress as factors that can promote systemic chronic inflammation. [4] These are proposed mechanisms and risk factors, not a recipe.

Does lowering inflammation help?

This is the key test, and the answer so far is "sometimes, in one setting".

Both trials were in people with heart disease risk, not healthy older adults treated for aging. CANTOS suggests that, for that group, an inflammation pathway matters; the cardiology review says whether modulating inflammation helps in non-cardiovascular problems is controversial. [2] Label: promising but limited for heart events in a high-risk group; insufficient evidence that reducing inflammation extends healthy life in general.