What can be done to prevent the onset of sun spots?

Pigmentation spots can have various origins (hormonal fluctuations, pregnancy, sun, genetics). Sun spots, also known as lentigos or age spots are due to repeated exposure to the sun's UV rays. Etymologically, lentigo refers to lentils. Sun spots take the form of small flat spots of light brown to black colour. They usually appear around the age of 50, or sometimes even earlier at 40 years old. They are much more prevalent in people with light phototypes.

Sun spots are caused and/or exacerbated by a phenomenon known as oxidative stress.As a reminder, this phenomenon results from the overproduction of pro-oxidant species in cells, and/or the reduction of cellular antioxidant capacity, and can damage DNA, cellular membrane lipids and proteins, leading to mutagenesis or cell death. Reactive oxygen species (ROS) are produced by mitochondria and peroxisomes during normal cellular metabolic processes. However, ROS production can be heightened under pathological conditions, such as inflammation and cancer, as well as when exposed to exogenous factors, like ultraviolet (UV) rays.

The skin is the largest organ interfacing with the environment, and a significant source of Reactive Oxygen Species (ROS) which are induced by sun exposure. Epidermal melanocytes are particularly vulnerable to excessive ROS production due to their specialised function: the synthesis of melanin, which is stimulated by sun exposure during the tanning process. When melanocytes are disrupted, they produce excess and disorganised melanin, leading to brown spots known as solar lentigines.

Lentigos are associated with skin ageing. As we age, the skin fails to fully protect itself from external aggressions and deteriorates. A dysfunction of melanocytes is observed, associated with the exhaustion of their pigmentary potential at the level of hair follicles. This phenomenon is also correlated with the consequences of repeated attacks of reactive oxygen species (or free radicals) on the nuclei of melanocytes and mitochondria. When this happens, the skin becomes vulnerable to UV rays, which are responsible for sun spots also referred to as "age spots".

Note:Solar lentigines are by definition benign lesions, but some can progress to precancerous lesions. This is then referred to as Dubreuilh's melanosis, sometimes also called "malignant lentigo". Even though the mutation from a benign lentigo to a malignant one is slow, it is essential to regularly visit your dermatologist to monitor the possible evolution of these age spots.

The emergence of certain brown spots is sometimes inevitable (especially those due to hormonal fluctuations such as pregnancy masks) but others can be avoided by adopting two essential practices.

• Use a sun protection suitable for your skin tone.

  Unprotected, prolonged and repeated exposure to the sun's UV rays is the cause of the appearance of sun spots. Therefore, it is essential to protect your skin!

  The choice of sun protection depends on each individual's phototype. According to the FITZPATRICK classification, skin types are categorised into 6 phototypes defined based on hair colour, complexion, frequency of sunburn, and type of tanning. Thus, individuals with red hair, freckles, and a pale complexion (phototype I), and those with blonde hair and fair skin (phototype II) should opt for a sun protection factor of 50. People with light brown hair and fair skin (phototype III) or brown/dark brown hair and slightly tanned skin (phototype IV) should lean towards a sun protection factor of 30 or even 50. Finally, for mixed-race skin of phototype V or black skin of phototype VI, a sun protection with a minimum factor of 30 is sufficient for protection.

• Applying antioxidant treatments.

  Sun spots are exacerbated by a phenomenon known as "oxidative stress", largely stimulated by UV rays. Oxidative stress causes the deterioration of healthy skin molecules and compounds. These are "attacked" by oxygen radical species (free radicals) generated in excess by the sun's UV radiation. Free radicals are particularly unstable compounds due to their unpaired electrons. In cosmetics, certain active ingredients have the ability to stabilise these free radicals by donating an electron, thus making them much less harmful to the skin and preventing the appearance of several deteriorations such as brown spots but also wrinkles, sagging etc... Among these preventive molecules on hyperpigmentation, we find the vitamin C, the resveratrol and also the ferulic acid which will neutralise the free radicals.

Thus, during your morning beauty routine, you can apply several treatments enriched with vitamin C. On clean, dry skin, apply the radiance lotion with vitamin C, which also containslemon verbena water (INCI: "Lippia Citriodora Leaf Water") for a light fruity scent. Concentrated in active ingredients to regulate the skin's pH, brighten the complexion and reduce the appearance of pigmentation spots, this toning lotion is applied with a cotton pad over the entire face, avoiding the eye contour, and does not need to be rinsed off. Thenapply the radiance face serum highly concentrated in vitamin C derivative (INCI: "Sodium Ascorbyl Phosphate"). This treatment also contains 3% ofAlbizia Julibrissin extract (INCI: "Albizia Julibrissin Bark Extract"). This Asian-origin plant revitalises the skin. Together, these ingredients help slow down photo-ageing and prevent the appearance of brown spots. If you wish to even out your complexion, ourtinted serum is also enriched with vitamin C and provides light coverage and a natural finish to the skin. Finally, don't forget to finish your routine with asun protection suitable for your phototype. At Typology, we offer two facial sun creams with two different sun protection factors (SPF): one SPF 30 and one SPF 50. Both are enriched with antioxidant agents such as karanja oil for the SPF 30 and limonium extract for the SPF 50.

Furthermore, the body is not immune to the appearance of sunspots, quite the contrary, so remember to protect yourself well. We also offer two levels of sun protection for the body, SPF 30 and 50.

Please note: even though sunscreen can protect the skin fromhyperpigmentation spots, we recommend avoiding sun exposure between 11am and 3pm.

• DENAT L. Melanocytes as instigators and victims of oxidative stress. Journal of Investigative Dermatology (2014).