Chronic Inflammation

Acute inflammation is a healthy, self-limiting response to injury or infection. Chronic low-grade inflammation is something different: a persistent, low-amplitude activation of the innate immune system without an acute trigger, sustained over years. It produces no redness or swelling and is detectable only through biomarkers, principally high-sensitivity C-reactive protein. Its clinical importance comes from its association with disease. Elevated hs-CRP predicts cardiovascular events independently of cholesterol, and the CANTOS trial demonstrated that directly inhibiting interleukin-1 beta reduced cardiovascular events without altering lipids — the strongest evidence that inflammation is causal rather than merely correlated. Similar associations exist for type 2 diabetes, some cancers and cognitive decline. The dominant driver in most people is visceral adipose tissue, which is metabolically active and secretes interleukin-6 and tumour necrosis factor alpha. Physical inactivity, poor sleep, smoking, periodontal disease and chronic psychological stress all contribute independently. This is where the marketing runs well ahead of the science. Anti-inflammatory supplements are sold aggressively, and while omega-3 and curcumin do produce measurable reductions in inflammatory markers, the reductions are modest and the evidence that lowering a marker improves outcomes is limited to specific settings. Weight loss, exercise and smoking cessation move these markers more than any supplement, and their benefit on hard outcomes is established rather than inferred. One practical caution: hs-CRP rises sharply with any acute infection, so a raised value should be rechecked at least two weeks after any illness before it is interpreted.

• •Persistent fatigue
• •Generalised aches and stiffness
• •Poor recovery from exercise
• •Disturbed sleep
• •Low mood
• •Frequent minor infections
• •Often entirely asymptomatic and detected only on blood tests

• •Visceral adiposity
• •Physical inactivity
• •Poor sleep and sleep apnoea
• •Smoking
• •Chronic psychological stress
• •Periodontal disease
• •Diets high in ultra-processed food and refined sugar
• •Excess alcohol
• •Autoimmune disease
• •Chronic infection
• •Gut dysbiosis and intestinal permeability

Visceral adipose tissue behaves as an endocrine organ, releasing interleukin-6 and tumour necrosis factor alpha and recruiting macrophages that shift toward a pro-inflammatory phenotype. Interleukin-6 drives hepatic C-reactive protein production, which is why hs-CRP tracks adiposity so closely. Parallel contributors include innate immune priming by metabolic signals, translocation of bacterial lipopolysaccharide across a compromised gut barrier, and cellular senescence with its associated secretory phenotype, which is thought to underlie much age-related inflammation.