Mineral water for skin care, the new trend from China.

While certainly safe for the skin, it is reasonable to question whether the use of mineral water for skincare is based on scientific principles. However, to date, there is no scientific study conducted on the benefits of mineral water in cosmetics. Nevertheless, many scientists have explored the properties of various thermal waters. Before we proceed, a quick definition is necessary:

• Natural Mineral Water : According to the Public Health Code, natural mineral water is microbiologically safe water that comes from an underground layer or deposit exploited from one or more natural or drilled springs constituting the source. It stands out for its purity and richness in minerals. The extraction of mineral water is done according to a strict legislative framework: these waters can only undergo a few treatments authorized by regulations, such as the separation of naturally present constituents like iron or sulfur.

• Thermal Water : According to the Ministry of Labor, Health, Solidarity, and Families, thermal water is a natural mineral water used for therapeutic purposes. It has been the subject of scientific research and its use is regulated in thermal centers or in cosmetics. However, its extraction process, as well as its richness in minerals, are identical to those of mineral water.

All thermal waters are natural mineral waters, but not all natural mineral waters are thermal waters.

However, their chemical composition varies greatly depending on the location from which they are extracted. This variability depends on the nature of the soils through which the water travels, which determines the minerals and trace elements it contains. If a mineral water and a thermal water are extracted from the same source, it can be assumed that they offer similar benefits. But this remains a hypothesis, due to the lack of scientific validation for mineral waters available in supermarkets. The properties of thermal waters, on the other hand, are well documented. These can be classified into different categories based on their chemical composition and have several virtues for the skin. Thermal waters are especially praised for their soothing, anti-inflammatory, and healing properties, particularly beneficial for sensitive skin. These virtues, derived from their mineral concentration, have been confirmed in numerous studies, conducted in vivo and in vitro.

One such study was conducted on 18 children with atopic dermatitis, 18 children without skin problems, 39 adults suffering from psoriasis, and 39 control adults. These volunteers underwent a three-week thermal cure, consisting of daily showers and thermal water spray baths for twenty minutes. Skin samples were taken before and after this period. After analysis, the scientists noted a significant decrease of 36.3% in interleukin-8 levels in the skin of children with atopic dermatitis. At the beginning of the study, this inflammatory marker was nearly seven times higher than in the skin of the controls. The SCORAD of children with atopic dermatitis, a tool used to assess the severity of eczema, also decreased by half. Similar results were obtained for the volunteers suffering from psoriasis, who saw their IL-8 levels halved.

The conclusions of several other studies are presented in the table below.