Free radicals
Oxidative stress and free radicals are inseparable concepts in health, ageing and aesthetic medicine. They are sometimes seen as abstract terms reserved for specialists or researchers. Yet they concern everyone because they play a major role in bodily function and many skin changes and diseases. This article clearly explains what free radicals are, how they act, how oxidative stress develops and, above all, how healthy habits and suitable medical care can prevent or limit harmful effects.
What are free radicals?
Free radicals are unstable molecules naturally produced during metabolic processes. During cellular respiration, cells use oxygen to produce energy. A small proportion becomes reactive species called free radicals. These have an unpaired electron, making them highly reactive. Seeking balance, they capture electrons from other structures, causing a chain reaction potentially damaging proteins, lipids and DNA.
Their presence is not inherently pathological. In moderate quantities, they support vital functions such as immune defence against infection or cellular communication. Problems arise when production exceeds natural defence capacity.
What is oxidative stress?
Oxidative stress is an imbalance between free radical production and the body's antioxidant neutralising capacity. Cells have sophisticated protection, including specific enzymes and dietary antioxidants. When radicals dominate, damage accumulates and compromises function.
This process is silent but gradual. It may accelerate skin ageing, impair quality and cause wrinkles, pigmentation spots and elasticity loss. More generally, oxidative stress is involved in chronic conditions such as cardiovascular and neurodegenerative disease or some cancers.
Sources of free radicals
There are two main source categories: endogenous and exogenous.
- Endogenous sources originate within the body. Cellular respiration, liver detoxification, inflammation or intense activity of certain immune cells naturally generate radicals.
- Exogenous sources are external stressors. Air pollution, smoking, alcohol, ultraviolet radiation, certain chemicals and an unbalanced diet increase production.
This dual contribution amplifies imbalance and explains why modern lifestyles promote oxidative stress.
Factors increasing free radical levels
Certain lifestyle and environmental elements strongly increase production. Smoking is particularly powerful because smoke contains thousands of toxic substances capable of massive unstable-molecule production. Excessive alcohol worsens matters, particularly in the liver metabolising ethanol under significant oxidative stress. Modern diets often too rich in refined sugars, saturated fats and processed foods also increase free radical levels.
Environmental stressors add to this. Air pollution exposes the body to fine particles and irritating gases that intensify reactive oxygen species. Excessive sun, particularly UV, directly weakens skin cell DNA and increases radicals. Chronic stress, insufficient sleep and overly intense exercise also contribute by exhausting recovery capacity.
Organs targeted by free-radical-related ageing
Radicals damage not only skin but many vital organs. Cardiovascular vulnerability is high because lipid oxidation in arterial walls promotes atherosclerotic plaques and cardiac events. The brain, with high oxygen consumption and lipid content, is another target. Accumulated oxidative damage is associated with gradual cognitive decline and neurodegenerative disease.
The liver, essential for detoxification, also experiences significant oxidative stress, particularly processing alcohol or some medicines. Eyes are exposed too, particularly the constantly light-exposed retina. Over time, this contributes to age-related macular degeneration, a major cause of vision loss in modern societies. Free-radical ageing therefore affects many systems beyond visible skin changes.
The effects of oxidative stress on skin
Skin, the most environmentally exposed organ, is particularly vulnerable. Free radicals damage collagen and elastin responsible for firmness and elasticity. They also disrupt epidermal barrier function and promote blemishes and inflammation.
Over time, this causes visible premature ageing: deeper wrinkles, laxity, pigmentation irregularities and lost radiance. These changes are major patient concerns in preserving youthfulness and quality.
The role of antioxidants
The body counters radicals with antioxidant defences: enzymes such as superoxide dismutase or catalase and dietary molecules such as vitamins C and E, beta-carotene, selenium, zinc or fruit and vegetable polyphenols.
Sufficient antioxidants are essential for balance and cellular protection. A varied diet rich in colourful plants is therefore among the best defences. Antioxidants trap radicals, stop chain reactions and repair certain damage.
Preventing oxidative stress through lifestyle
Prevention mainly relies on daily habits. A balanced diet rich in fruit, vegetables, pulses, whole grains and healthy fatty acids supplies natural antioxidant resources. Reducing smoking and alcohol is decisive, as is limiting sun exposure.
Regular moderate exercise protects by improving circulation and stimulating natural defences. Conversely, overly intense exertion increases radicals. Psychological stress management is also crucial because chronic stress increases production.
Medical and aesthetic strategies
Medical approaches limit or repair skin effects. Topical antioxidants such as stabilised vitamin C, ferulic acid or polyphenols are increasingly used in dermocosmetic routines, strengthening defences and improving radiance.
Gentle peels, photobiomodulation or injections of certain biostimulators (collagen stimulators) encourage regeneration and strengthen tissues. The aim is restarting collagen production, improving quality and slowing visible ageing.
Specific antioxidant dietary supplements also exist. However, prescriptions must be adapted and personalised because excess can be counterproductive. Medicine always favours considered balance respecting individual physiology.
The link between oxidative stress and overall ageing
Beyond skin, oxidative stress accelerates overall ageing. Damaged DNA, weakened membranes and altered proteins accumulate, gradually reducing regenerative capacity. This contributes to declining vital functions and age-related disease.
Addressing oxidative stress therefore extends beyond aesthetics. It is an overall health issue aimed at preserving energy, vitality and longevity.
The importance of personalised care
Each person has unique metabolism influenced by genes, environment and lifestyle, so manifestations differ. Assessing condition, habits and specific needs is essential before proposing a strategy.
Personalised care preserves beauty and promotes general well-being. Medical guidance provides nutritional and lifestyle advice and targeted treatments according to aesthetic goals and individual physiology.
