Antioxidant cream: what are its benefits for the skin?

An antioxidant is an agent that possesses the property ofpreventing or slowing down the oxidation process of a substrate, and therefore the production of free radicals. Within the body, there is a constant balance between oxidative defences and pro-oxidant species: in other words, antioxidants are continuously eliminating free radicals. Although it has been proven that the presence of small amounts of free radicals are necessary for the proper functioning of metabolism (defence mechanism against microbes, elimination of old or defective cells, etc...), they can become harmful if they are produced in excess.

An imbalance then sets in (excessive production of free radicals or absence/deficiency in antioxidants) and reactive oxygen species (ROS) begin to cause damage to vital components of cells (DNA, proteins, lipids...) with the result being a disruption in the skin's natural ability to regenerate and in cellular communication, a premature ageing of the skin or even in the long term being the cause of skin cancers. Indeed, free radicals will activate a myriad of signalling pathways which among other things lead to a reduction in collagen production, and the synthesis and activation of matrix metalloproteinases (MMP) responsible for the degradation of connective tissue, thereby promoting skin ageing.

Although free radicals are a natural by-product of processes occurring within the body, these incomplete molecules are not solely generated by the body itself. Numerous external factors (pollution, stress, lack of sleep, sedentary lifestyle, UV rays, smoking, alcohol consumption, electromagnetic waves, allergens, etc...) are known to trigger or increase their production, which then manifests as signs of ageing (age spots, skin sagging, fine lines, etc...), a loss of radiance and an increase in skin sensitivity (photosensitisation, redness, irritations…).

To produce energy, the body's cells undergo oxidations, concurrently generating free radicals. These are atoms that carry one or more unpaired electrons on their outer layer. However, the presence of these single electrons makes the molecule unstable and hyper-reactive towards other substances.

This chemical entity will strive at all costs to react with neighbouring molecules in order to regain an electron and form a stable pair, destabilising them in the process. Consequently, the attacked molecule becomes unstable in turn, thus creating a new free radical. However, when the number of free radicals exceeds what the skin can naturally eliminate, this results in damage to proteins, unsaturated lipids of cell membranes, and DNA. Among the damaged cells are keratinocytes, melanocytes, and fibroblasts that produce collagen, elastin, hyaluronic acid, or melanin.

On the other hand, it has been proven that antioxidants are capable of stabilising these molecules and counteracting their formation, thereby halting this chain reaction and protecting the molecules from oxidation. How do they work? These chemical species possess extra electrons and have the ability to donate electrons. They also prevent the triggering of glycation and lipid peroxidation reactions, and the creation of DNA damage. The care enriched with antioxidants then helps to combat the phenomenon of oxidation that promotes premature skin ageing.