Inflammaging: How Chronic Low-Grade Inflammation Accelerates Every Aspect of Aging

What Is Inflammaging?

In 2000, Italian immunologist Claudio Franceschi published a paper coining the term "inflammaging" -- a portmanteau of inflammation and aging. The concept: as humans age, they develop a chronic, low-grade, sterile inflammatory state that is systemic rather than localized and persistent rather than acute. This smoldering inflammation is not the immune response you experience during an infection. There is no pathogen, no injury, no visible signs of illness. But the inflammatory machinery is running -- quietly, continuously, and at a cost.

Inflammaging is now understood as one of the central mechanisms driving age-related decline. It contributes to sarcopenia, cardiovascular disease, cognitive decline, insulin resistance, osteoporosis, and cancer risk. It is also self-reinforcing, which is what makes it particularly significant.

How to Identify It: The Markers

Inflammaging is measured through blood biomarkers. The most clinically relevant:

• High-sensitivity C-reactive protein (hs-CRP). CRP is produced by the liver in response to IL-6. The high-sensitivity assay detects the low levels relevant to chronic inflammation rather than acute infection. Values below 1 mg/L are considered low risk; 1-3 mg/L is intermediate; above 3 mg/L is high and associated with significantly elevated cardiovascular and all-cause mortality risk. This is the most accessible marker -- available on standard lab panels and generally covered by insurance.
• Interleukin-6 (IL-6). A cytokine that rises consistently with age and is one of the primary drivers of the systemic inflammatory state. IL-6 is also secreted by senescent cells as part of the SASP (senescence-associated secretory phenotype). Elevated IL-6 predicts muscle loss, cognitive decline, and mortality across multiple large population studies.
• Tumor necrosis factor-alpha (TNF-alpha). Another cytokine elevated in inflammaging, with particularly strong connections to insulin resistance and muscle catabolism.
• Interleukin-1 beta (IL-1beta). Elevated in obesity-related inflammation and implicated in beta-cell dysfunction and type 2 diabetes progression.

If you want to understand your own inflammatory burden, hs-CRP is the starting point -- it is inexpensive, widely available, and meaningfully predictive. Ask your physician to include it on your next panel.

What Drives It: The Sources of Chronic Inflammation in Aging

Inflammaging does not have a single cause. It emerges from the convergence of several processes that build with age.

Senescent Cells and the SASP

Senescent cells -- cells that have stopped dividing but remain metabolically active -- secrete a complex mix of cytokines, chemokines, growth factors, and matrix-degrading enzymes collectively called the senescence-associated secretory phenotype. SASP is one of the most significant drivers of inflammaging. Senescent cells accumulate in virtually every tissue with age. Each one is a small, persistent inflammatory signal. Collectively, they create the background noise of chronic inflammation that characterizes aging tissue.

Gut Dysbiosis and Increased Intestinal Permeability

The gut microbiome changes substantially with age. Diversity declines, beneficial species decrease, and the gut epithelium -- the single-cell-thick barrier between the gut lumen and the bloodstream -- becomes more permeable. This allows bacterial products, particularly lipopolysaccharide (LPS) from gram-negative bacteria, to leak into circulation and trigger immune activation. This "leaky gut" contribution to systemic inflammation is now well-documented and represents a direct mechanistic link between gut dysbiosis and inflammaging.

Visceral Adipose Tissue

Fat stored around the organs -- visceral adipose tissue -- is metabolically active and pro-inflammatory. It secretes its own cytokines (adipokines), including IL-6 and TNF-alpha. As visceral fat accumulates with age (a tendency driven partly by declining sex hormones and shifting metabolism), it becomes a persistent source of systemic inflammation. This is one reason waist circumference is a better predictor of metabolic and cardiovascular risk than BMI.

Mitochondrial Damage

Damaged mitochondria release mitochondrial DNA (mtDNA) into the cytoplasm. The immune system recognizes mtDNA as foreign -- it shares structural features with bacterial DNA, reflecting mitochondria's ancient bacterial origins. This triggers an innate immune response and contributes to the inflammatory background of aging.

Immunosenescence

The immune system itself ages -- a process called immunosenescence. Adaptive immune function declines (weaker responses to new pathogens and vaccines), while innate immune activation becomes dysregulated and prone to generating inflammatory signals. Chronic viral infections, particularly cytomegalovirus (CMV), which is carried asymptomatically by the majority of older adults, place ongoing demands on immune resources and contribute to the inflammatory load.

The Feedback Loop

What makes inflammaging particularly insidious is that it drives the very processes that generate more inflammation. SASP from senescent cells damages neighboring cells, pushing them toward senescence. Chronic inflammation impairs mitochondrial function, generating more mitochondrial damage and oxidative stress. Gut permeability worsens with inflammation, which worsens gut permeability. The system is self-reinforcing, which is why early intervention has disproportionate value.

What Reduces Inflammaging

The good news is that the same lifestyle inputs that address other hallmarks of aging also reduce the inflammatory burden.

• Exercise -- particularly aerobic exercise. Exercise produces a paradox: it causes acute inflammation (that is part of how it drives adaptation), but consistent training results in a lower resting inflammatory state. Regular aerobic exercise reduces IL-6, TNF-alpha, and CRP at baseline. Resistance training adds to this by reducing visceral fat and improving insulin sensitivity. The anti-inflammatory effect of exercise is one of the strongest, best-replicated findings in the field.
• Omega-3 fatty acids. EPA and DHA -- found in fatty fish and algae-based supplements -- are precursors to anti-inflammatory signaling molecules (resolvins and protectins). Multiple RCTs show meaningful reductions in hs-CRP and IL-6 with 2-4g daily of EPA+DHA. This is one of the strongest supplement signals in inflammation research.
• Visceral fat reduction. Since visceral adipose tissue is a direct inflammatory source, reducing it through caloric deficit and exercise directly reduces inflammatory output. Waist circumference response to lifestyle intervention tracks closely with hs-CRP reduction.
• Quality sleep. Sleep deprivation acutely raises inflammatory markers. Chronic poor sleep -- even mild insufficiency over weeks -- produces a sustained elevation in IL-6 and CRP. Sleep is not a passive state but an active anti-inflammatory one.
• Dietary pattern. The Mediterranean dietary pattern -- high in polyphenols, fiber, olive oil, and fish -- consistently associates with lower inflammatory markers in population studies and some RCTs. Ultra-processed foods, refined carbohydrates, and trans fats have the opposite effect.
• Gut microbiome support. Dietary fiber (particularly prebiotic fiber from vegetables, legumes, and whole grains), fermented foods, and reduction of ultra-processed food improve microbiome diversity and reduce intestinal permeability. This directly addresses one of inflammaging's primary fuel sources.

The Practical Priority

If you want a single proxy for how well you are controlling inflammaging, request an hs-CRP on your next blood panel. A level below 1 mg/L suggests your inflammatory burden is low. If it is elevated, the interventions above -- particularly consistent exercise, omega-3 supplementation, and reducing visceral fat -- have the strongest evidence for bringing it down. These are not mild suggestions; they are addressing one of the central mechanisms of accelerated aging.