Free radicals, antioxidants, and the balance between them

Free radicals, more precisely, reactive oxygen species (ROS), are unstable molecules produced as a normal byproduct of cellular energy production (mitochondrial respiration) and immune function. They are not inherently damaging at low concentrations; they serve important signalling functions and are used by immune cells to kill bacteria. The problem is when production exceeds the body's capacity to neutralise them.

Antioxidants are the molecules that neutralise free radicals, donating electrons to stabilise them without becoming damaging radicals themselves. The body produces intrinsic antioxidants, glutathione, superoxide dismutase, catalase, and obtains extrinsic antioxidants from diet: vitamin C, vitamin E, polyphenols, selenium, zinc, and CoQ10. When the rate of free radical production exceeds the combined capacity of intrinsic and extrinsic antioxidant defence, the resulting imbalance, oxidative stress, produces progressive damage to cellular structures: lipid membranes, proteins, and DNA.

"Oxidative stress is not a metaphor for cellular ageing. It is a measurable, specific biochemical state with direct consequences for tissue integrity, addressable through targeted nutritional correction."

What produces excess oxidative stress

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Mitochondrial dysfunction
Impaired mitochondrial efficiency produces electron leakage that generates superoxide, the primary mitochondrial free radical, at rates exceeding the normal antioxidant clearance capacity. This is a key pathway by which mitochondrial dysfunction (in CFS, fibromyalgia, and ageing) produces both energy deficit and oxidative tissue damage simultaneously.
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Systemic inflammation
Activated immune cells produce ROS as part of the inflammatory response, particularly through the NADPH oxidase pathway. Chronic inflammation therefore produces chronic oxidative stress, and the two amplify each other in a self-sustaining cycle.
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Elevated blood glucose
Hyperglycaemia directly produces ROS through glycation reactions, the same advanced glycation end-products (AGEs) that damage blood vessels, nerves, and kidneys in diabetes. Glucose auto-oxidation is one of the most potent sources of oxidative stress in metabolic disease.
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Environmental exposures
Cigarette smoke, air pollution, excessive UV radiation, and heavy metal exposure each generate oxidative stress through direct free radical production or by depleting antioxidant reserves, explaining why these exposures accelerate the tissue damage of chronic disease.
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Psychological stress
Stress hormones, particularly catecholamines, stimulate NADPH oxidase activity, producing superoxide in vascular tissue. This is one mechanism by which chronic stress elevates cardiovascular risk: through oxidative endothelial damage that impairs nitric oxide production and promotes atherosclerosis.

Where oxidative stress causes damage

In joints, ROS directly degrade cartilage matrix proteins, including collagen and aggrecan, producing the cartilage loss that characterises osteoarthritis. Chondrocytes (cartilage cells) are particularly vulnerable to oxidative damage because cartilage is avascular (without blood supply) and therefore receives antioxidant nutrients relatively slowly. This explains why antioxidant nutritional supplementation, vitamin C, CoQ10, curcumin, helps reduce joint inflammation markers and slows cartilage loss.

In blood vessels, ROS oxidise LDL cholesterol, converting it to oxidised LDL (ox-LDL), the form that is actually taken up by macrophages in the arterial wall to form foam cells and atherosclerotic plaques. ROS also directly quench nitric oxide, reducing the vasodilatory capacity of the endothelium. Endothelial dysfunction is, at its biochemical core, a state of oxidative stress in the vessel wall.

In nerve tissue, neurons are highly susceptible to oxidative damage because of their high metabolic rate and limited antioxidant defence capacity. Mitochondrial oxidative stress in nerve cells is the primary mechanism of diabetic neuropathy, producing the nerve damage that conventional blood sugar management does not reverse, and that alpha-lipoic acid (a potent neurological antioxidant) addresses directly.

In immune tissue, oxidative stress impairs the function of T-regulatory cells that suppress autoimmune activation, directly contributing to autoimmune disease activity. This is why antioxidant correction is a meaningful clinical adjunct in psoriasis, rheumatoid arthritis, and Hashimoto's thyroiditis.

Osteoarthritis
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Rheumatoid Arthritis
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Type 2 Diabetes
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Endothelial Dysfunction
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Diabetic Microvascular
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Chronic Fatigue Syndrome
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Fibromyalgia
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Psoriasis
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Antioxidant correction as a clinical intervention

Vitamin C is the primary water-soluble antioxidant, recycling vitamin E after it has neutralised lipid-phase free radicals, regenerating glutathione, and directly scavenging aqueous free radicals. At therapeutic doses (above dietary intakes), vitamin C helps reduce oxidative stress markers and supports collagen synthesis.

CoQ10 serves dual roles as a mitochondrial electron carrier and as a fat-soluble antioxidant that prevents oxidative damage in cell membranes. It is directly relevant to conditions involving mitochondrial dysfunction (CFS, fibromyalgia, cardiac disease) and is depleted by statin medications, making CoQ10 restoration clinically important in statin users with muscle or fatigue symptoms.

Alpha-lipoic acid (ALA) is unique in being both water- and fat-soluble, providing antioxidant protection in all cellular compartments. It regenerates glutathione, vitamin C, and vitamin E, and has direct clinical evidence for diabetic neuropathy through its protection of nerve mitochondria from oxidative damage.

Dietary polyphenols, from colourful plant foods, olive oil, green tea, and dark chocolate, activate the Nrf2 pathway, which upregulates the body's intrinsic antioxidant enzyme production. This is more effective than exogenous antioxidant supplementation for long-term oxidative stress reduction, and explains why dietary pattern change produces more durable antioxidant effect than supplementation alone.

In CLCC care, oxidative stress markers, including homocysteine, oxidised LDL, and 8-OHdG where available, are assessed in the context of the patient's condition and dietary pattern. Antioxidant correction is then targeted to the specific tissue experiencing oxidative damage, not provided generically.