In 2023, a landmark revision of the hallmarks of ageing added something that had been hiding in plain sight for decades: chronic inflammation. The original nine hallmarks, set out in 2013, already hinted at it — damaged DNA, exhausted stem cells and senescent "zombie" cells all release inflammatory signals. But the updated framework, now twelve hallmarks strong, gave chronic inflammation its own entry, acknowledging that the slow, sterile fire the field calls "inflammaging" is not merely a by-product of other damage — it is a driver of ageing in its own right.
This article explains what inflammaging is, why it matters for long-term health, and what high-sensitivity C-reactive protein (hs-CRP) — the most accessible blood marker of systemic inflammation — can and cannot tell you about it.
What inflammaging actually means
The term was coined in 2000 by the immunologist Claudio Franceschi to describe a paradox: as we age, the immune system simultaneously weakens (immunosenescence) and becomes chronically activated, producing low-level inflammation even without an infection to fight. Two decades of research have fleshed out the picture. Inflammaging is now understood as a complex, systemic, low-grade pro-inflammatory state driven by multiple converging sources — senescent cells secreting inflammatory molecules (the senescence-associated secretory phenotype, or SASP), mitochondrial dysfunction leaking damage signals, shifts in gut-barrier integrity, accumulating cellular debris, and changes in body-fat distribution that favour visceral adipose tissue, itself an active inflammatory organ.
What makes inflammaging insidious is that it operates below the threshold of symptoms. You do not feel acutely unwell; there is no fever, no swelling you can point to. Yet the low-grade signalling — interleukin-6 (IL-6), tumour necrosis factor-alpha (TNF-α), and the liver's downstream read-out, C-reactive protein (CRP) — grinds away at tissues over years.
Why it matters: the disease links
The evidence connecting chronic low-grade inflammation to age-related disease is STRONG, built on large prospective cohorts and, crucially, a proof-of-concept randomised trial.
Cardiovascular disease. A meta-analysis of prospective cohort studies found that people with the highest hs-CRP levels had significantly elevated risks of both cardiovascular and all-cause mortality, compared with those in the lowest category. A separate dose-response meta-analysis of multiple cohorts confirmed that the relationship between CRP and both all-cause and cardiovascular mortality is non-linear, with risk increasing across the concentration range. Inflammation is not just a bystander in atherosclerosis; the CANTOS trial (10,061 patients, randomised, double-blind) demonstrated that blocking a single inflammatory cytokine (interleukin-1β) with canakinumab reduced major cardiovascular events by about 15%, independent of any change in cholesterol — evidence from a randomised trial that lowering inflammation itself can lower cardiovascular risk.
Frailty. A systematic review and meta-analysis of cross-sectional studies found that both frail and pre-frail older adults had significantly higher CRP and IL-6 levels than robust peers. The association is consistent enough that some researchers now describe frailty as an inflammatory phenotype of ageing — though the longitudinal evidence (does inflammation predict who becomes frail?) is still maturing, and the relationship is likely bidirectional.
Neurodegeneration. Chronic peripheral inflammation is associated with worse cognitive trajectories and higher dementia risk in several large cohorts, with inflammation-related proteins measured at baseline predicting incident dementia over extended follow-up periods. The mechanisms are not fully settled — peripheral cytokines may cross the blood-brain barrier, activate microglia, and accelerate neuroinflammation — but the epidemiological signal is consistent.
The honest gap. Inflammaging is strongly associated with these outcomes, and the CANTOS trial provides causal evidence for the cardiovascular arm specifically. However, no randomised trial has yet shown that lowering chronic inflammation in otherwise healthy people extends human lifespan. The evidence is observational for all-cause mortality and for neurodegeneration; causal language must be capped at association for those links.
hs-CRP: the accessible read-out — and its limits
High-sensitivity CRP is one of the most widely used blood markers for tracking low-grade systemic inflammation. It is cheap, standardised, and measured in virtually every clinical laboratory. The "high-sensitivity" prefix simply means the assay can detect the low concentrations (below 10 mg/L) relevant to chronic inflammation, rather than only the dramatic spikes seen in acute infection.
What it does well. In population studies, a single hs-CRP measurement stratifies cardiovascular and all-cause mortality risk consistently across a range of populations. It captures the net inflammatory output of many upstream processes — visceral fat, senescent cells, poor sleep, a pro-inflammatory diet, physical inactivity — and condenses them into one number.
What it does not do. hs-CRP is non-specific. An acute infection, a dental procedure, a vigorous training session, or a minor injury can spike it for days to weeks. A single high reading does not mean you are "inflamed" in the chronic sense — it means something raised CRP, and context matters. It also does not tell you why inflammation is elevated; it is a thermometer, not a diagnosis. And while hs-CRP predicts risk at the population level, its predictive power for any single individual is modest — it is most useful as a trend over time, not a one-off verdict.
This is precisely why repeat measurement matters. A single hs-CRP reading is a snapshot; two or three readings over months, ideally taken when you feel well and have not recently been ill or injured, begin to reveal whether your baseline inflammatory tone is drifting up, holding steady, or coming down after a lifestyle change.
What the evidence says about lowering chronic inflammation
If inflammaging is a hallmark of ageing, the practical question is whether anything you can do about it actually moves the needle. The short answer: several lifestyle factors have consistent evidence for reducing hs-CRP, though none is a magic switch.
Physical activity. A meta-analysis of randomised controlled trials in healthy middle-aged and older adults found that aerobic exercise programmes were associated with reductions in inflammatory markers, including CRP, compared with inactive controls. The effect is modest but reproducible, and it complements the independent mortality benefit of cardiorespiratory fitness.
Dietary pattern. A systematic review and meta-analysis of randomised controlled trials in patients with coronary heart disease found that Mediterranean-style dietary patterns were associated with reductions in CRP. The benefit likely comes from the pattern as a whole — high in polyphenols, fibre, omega-3 fatty acids — rather than any single nutrient, and effect sizes vary across populations.
Body composition. Visceral adipose tissue is among the most potent drivers of inflammaging, and fat loss has been associated with lower CRP levels in intervention studies. This is one reason the metabolic benefits of exercise extend beyond the session itself.
Other modifiable inputs. Observational data link poor sleep quality, psychological stress and smoking to elevated inflammatory markers. However, RCT evidence for specific interventions targeting these pathways (beyond the broader lifestyle changes above) is thinner, and effect sizes are less well established.
None of these is a treatment for a disease; they are modifiable inputs associated with lower chronic inflammation in healthy adults. Whether lowering hs-CRP through lifestyle change translates to the same mortality-risk reduction seen in epidemiological studies remains an open question — plausible, supported by mechanism, but not yet proven by a long-term RCT in the general population.
Rating the evidence
| Claim | Rating | Key gap | |-------|--------|---------| | Chronic inflammation is a hallmark of ageing | STRONG — consensus framework, large mechanistic base | Hallmark status is expert-led taxonomy, not a single falsifiable hypothesis | | Higher hs-CRP is associated with higher all-cause and CV mortality | STRONG — multiple large meta-analyses, dose-response | Observational; residual confounding cannot be fully excluded | | Blocking inflammation (IL-1β) reduces CV events | STRONG — CANTOS RCT | One drug, one pathway, post-MI population — not healthy ageing | | Chronic inflammation linked to frailty | STRONG (cross-sectional), EMERGING (longitudinal/causal) | Bidirectional relationship; limited prospective data | | Chronic inflammation linked to dementia risk | EMERGING — consistent observational signal | No anti-inflammatory RCT has shown dementia prevention | | Lifestyle change lowers hs-CRP | STRONG for exercise and diet pattern | Whether CRP reduction = mortality reduction is unproven in healthy adults |
How Omniwo helps you measure this
Chronic inflammation is, by definition, something you cannot feel — and a one-off reading tells you less than a trend. That is where repeat, accessible testing earns its place.
Omniwo's Quick Wellness Check includes hs-CRP alongside thyroid, iron and vitamin-D markers, delivered as an at-home finger-prick kit. The idea is straightforward: take a baseline when you are well (no recent illness, injury or unusual exertion), change one input — a training block, a dietary shift, a sleep overhaul — and re-test after two to three months to see whether your inflammatory baseline has moved.
hs-CRP has its own biomarker page on Omniwo, explaining what healthy ranges look like and how to interpret a result in context. If you want a broader ageing picture, Omniwo's BioAge score — a composite of multiple validated markers — places hs-CRP alongside metabolic and organ-function signals so you can see how systemic inflammation fits into your overall ageing trajectory.
What Omniwo does not do is diagnose a disease, identify the source of inflammation, or replace your GP. If your hs-CRP is persistently elevated and you are unsure why, that is a conversation for a clinician — the test gives you the signal; a doctor interprets it in the context of your full health picture.
Omniwo's tests and content are for wellness and educational insight. They do not diagnose, treat, cure or prevent any disease, and do not replace advice from a qualified healthcare professional.
Sources
-
López-Otín C, Blasco MA, Partridge L, Serrano M, Kroemer G. Hallmarks of aging: An expanding universe. Cell. 2023;186(2):243–278. doi:10.1016/j.cell.2022.11.001 (PMID: 36599298)
-
Baechle JJ, Chen N, Makhijani P, Winer S, Furman D, Winer DA. Chronic inflammation and the hallmarks of aging. Molecular Metabolism. 2023;74:101755. doi:10.1016/j.molmet.2023.101755 (PMID: 37348790)
-
Franceschi C, Garagnani P, Parini P, Giuliani C, Santoro A. Inflammaging: a new immune–metabolic viewpoint for age-related diseases. Nature Reviews Endocrinology. 2018;14(10):576–590. doi:10.1038/s41574-018-0059-4 (PMID: 30046148)
-
Ferrucci L, Fabbri E. Inflammageing: chronic inflammation in ageing, cardiovascular disease, and frailty. Nature Reviews Cardiology. 2018;15(9):505–522. doi:10.1038/s41569-018-0064-2 (PMID: 30065258)
-
Li Y, Zhong X, Cheng G, et al. Hs-CRP and all-cause, cardiovascular, and cancer mortality risk: A meta-analysis. Atherosclerosis. 2017;259:75–82. doi:10.1016/j.atherosclerosis.2017.02.003 (PMID: 28327451)
-
Ni P, Yu M, Zhang R, et al. Dose-response association between C-reactive protein and risk of all-cause and cause-specific mortality: a systematic review and meta-analysis of cohort studies. Annals of Epidemiology. 2020;51:20–27.e11. doi:10.1016/j.annepidem.2020.07.005 (PMID: 32702432)
-
Ridker PM, Everett BM, Thuren T, et al. Antiinflammatory Therapy with Canakinumab for Atherosclerotic Disease. New England Journal of Medicine. 2017;377(12):1119–1131. doi:10.1056/NEJMoa1707914 (PMID: 28845751)
-
Soysal P, Stubbs B, Lucato P, et al. Inflammation and frailty in the elderly: A systematic review and meta-analysis. Ageing Research Reviews. 2016;31:1–8. doi:10.1016/j.arr.2016.08.006 (PMID: 27592340)
-
Nedelec T, Couvy-Duchesne B, Monnet F, et al. Association of the inflammation-related proteome with dementia development at older age: results from a large, prospective, population-based cohort study. Alzheimer's Research & Therapy. 2022;14:128. doi:10.1186/s13195-022-01063-y (PMID: 36085234)
-
Zheng G, Qiu P, Xia R, et al. Effect of Aerobic Exercise on Inflammatory Markers in Healthy Middle-Aged and Older Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Frontiers in Aging Neuroscience. 2019;11:98. doi:10.3389/fnagi.2019.00098 (PMID: 31080413)
-
Mayr HL, Thomas CJ, Tierney AC, et al. Mediterranean-type diets and inflammatory markers in patients with coronary heart disease: a systematic review and meta-analysis. Nutrition Research. 2018;50:10–24. doi:10.1016/j.nutres.2017.10.014 (PMID: 29540268)
This article is educational and not medical advice. See our medical disclaimer.