All about red algae.

Thered algae or Rhodophytes belong to a large taxon of marine algae that encompasses several species. Their colour is attributed to their pigment composition, characterised by the presence of a single type ofchlorophyll. They predominantly grow on the Atlantic coast and are harvested on beaches. There are several varieties of red algae: the Chondrus crispus, the Porphyra conchocelis, the Palmaria palmata...

In skincare, but also in the food industry, the carrageenan is a sulphated polysaccharide extracted from red seaweeds that is used to thicken formulas and give them a gel-like consistency. Traditionally extracted from the species Chondrus crispus (Irish moss), carrageenan is now predominantly derived from the species Kappaphycus alvarezii and Eucheuma denticulatum.

In skincare and haircare, red algae is often used to thicken formulas. Indeed, red algae extract contains carrageenans, natural polysaccharides composed of sulphated D-galactose residues. When in contact with water, these biopolymers unfold and form a gelified network. As a natural thickening agent, red algae extract is often used in organic cosmetics to replace certain synthetic gelling agents such as carbomers.

Beyond its primarily functional capacity, red algae brings benefits to the skin. Its moisturising power allows it to retain water in the superficial layers of the skin, thereby reducing insensible water loss. When applied externally, red algae extract combats the tightness often associated with skin dryness, and prevents the appearance of dehydration fine lines.

Furthermore, red algae extract is capable of stimulating the synthesis of hyaluronic acid. As a reminder, hyaluronic acid is a biomolecule predominantly produced by the dermal fibroblasts that ensures skin hydration and gives it its plump and rejuvenated appearance.

Over the years, not only does its content decrease but its quality also changes. Each decade, we lose about 6% of hyaluronic acid.

This drastic decrease leads to an atrophy of the fat pockets located deep within the dermis, which are responsible for the emergence of wrinkles and fine lines on the skin's surface. Therefore, stimulating its synthesis allows for the maintenance of plump skin for as long as possible.

Furthermore, red algae extract limits imperfections on the skin's surface. Indeed, studies have demonstrated thebactericidal activity of carrageenan against the Staphylococcus epidermidis and theEnterococcus faecalis, two microorganisms implicated in the development of acne and associated inflammatory reactions.

Finally, the red algae extract helps to stimulate the synthesis of ceramides which strengthens the skin's barrier and limits insensible water loss. As a reminder, ceramides are lipids organised into dense and structured layers that form the intercellular cement.