A cut apple left on the table turns brown. A metal railing rusts by the sea.
In our bodies, oxygen presents the same paradox: without it, there is no life. Our cells need it to produce energy, but this process also generates highly reactive molecules, including the well-known free radicals.
Oxidative stress, simply put: a balance that tips
After a meal, nutrients from food reach our cells. Mitochondria, tiny powerhouses within our cells, convert them into energy with the help of the oxygen we breathe. A magnificent concerto that allows us to think, observe, laugh, dance... but it comes at a price: a small amount of reactive species is produced.
And that is normal.
The body has its own antioxidant defences. Some neutralise some of these reactive species; other systems repair the damage that may occur.
However, this natural production is supplemented by the effects of certain exposures and situations: UV rays, cigarette smoke, pollution, certain infections, or very intense physical exercise can increase the production of these radicals. If this pressure accumulates over time and the defences can no longer keep up, the balance tips: this is oxidative stress. In other words, the production of radicals outpaces our defence capabilities.
The problem, therefore, is not their presence, but a sustained excess compared to what the body can handle.
Why aren't free radicals necessarily bad?
In small doses, reactive species also serve as messengers. They trigger certain adaptation responses and can stimulate our own defence systems.
A kind of little booster shot that keeps the defence system running, but also helps eliminate some pathogens. They are therefore vital to our body.
Physical exercise illustrates this well: it temporarily increases the production of free radicals, which serve as a signal to the body to strengthen its antioxidant defences and improve its adaptation to exercise.
The goal, therefore, is not zero free radicals, but a level that the body is able to handle.
Can you feel that you are experiencing oxidative stress?
Fatigue, difficulty recovering, less radiant complexion... these signs are sometimes associated with oxidative stress, but none belong exclusively to it. Feeling tired, therefore, does not allow you to conclude that you have "too much" of it.
Researchers can observe different markers, but no single test today summarises the situation with a simple number. So you probably won't see this on your next blood test results: "oxidative stress: 7/10".
A temporary increase can be perfectly normal. The problem arises mainly when an imbalance sets in over time.
Why is it talked about so much with age?
With age, the balance can become harder to maintain: some sources of reactive species increase, while several defence, adaptation, and repair systems become less effective.
Oxidation can then affect cell membranes, certain proteins, or even DNA. However, it does not explain ageing on its own: genetics, inflammation, metabolism, and the environment are also involved. Oxidative stress contributes, like other factors, to ageing.
Oxidative stress is one piece of the puzzle, not the whole puzzle.
Why is the skin particularly exposed?
The skin is on the front line against a particularly aggressive environment. UV rays, in particular, increase the production of reactive species and are a major environmental factor in premature skin ageing.
With repeated exposure, collagen and other elements that support the skin can degrade and become disorganised. On the surface, this contributes to wrinkles, loss of firmness, a less even texture, or changes in pigmentation.
What can really be done on a daily basis?
We cannot eliminate all production of free radicals. And that is not desired. We can, however, reduce what overloads the balance and help the body defend itself better.
A few simple actions really count when they become habits: not smoking, protecting your skin from the sun, getting enough sleep, recovering, moving regularly, and eating a varied diet.
Fruits, vegetables, legumes, seeds, and nuts notably provide vitamins and minerals. Vitamin C and zinc, for example, contribute to the protection of cells from oxidative stress.
And antioxidants, what role do they really play?
Antioxidants act complementarily. Some directly help neutralise reactive molecules, while others support our body's own defence systems. Combining them thus allows us to act on several levels: help protect cells and support the body's own antioxidant defences over time.
Astaxanthin is one example. An analysis grouping several human studies observed an improvement in skin hydration and elasticity with an oral intake compared to a placebo.
We detail this work in our article on its benefits.
At Thaléïs, SkinGlow notably combines vitamin C and zinc. Our Astaxanthin provides 8 mg of astaxanthin derived from Haematococcus pluvialis.
The real story of oxidative stress is a story of balance
Our body produces reactive species, uses them, keeps them in check, repairs the damage and starts again.
The goal is not to eliminate all oxidation, but to help the body keep the balance on the right side.
Varied diet, sun protection, movement, sleep, less tobacco, and, when it makes sense, a few well-chosen nutrients: nothing spectacular taken in isolation.
But over years, the little things repeated for a long time are rarely little things. And as always, in nutrition, it is a story of balance.