Whey Protein\Lactis Protein\Proteine Du Petit-Lait is a form of protein derived from milk that is used in cosmetics and personal care products as a skin and hair conditioning agent.
There are two types of protein found in milk: whey and casein. Whey is the translucent liquid that is left over when milk is coagulated during the process of cheese production, after coagulation and curd removal. It contains everything that is soluble from milk after the pH is dropped to 4.6 during the coagulation process. The term “whey” refers to a complex substance that is separated from the liquid and made up of a combination of globular protein, lactose, minerals, immunoglobulins, and trace amounts of fat. Whey is primarily lactalbumin (~4%) and lactoglobulin (~10%).
In cosmetics and personal care products, whey protein may be present as three major forms: whey protein concentrate, whey protein isolate, or hydrolyzed whey protein. Whey protein concentrate and whey protein isolate are produced by physical separation techniques such as precipitation, filtration, dialysis and/or ion exchange. Non-protein constituents are removed from whey so that the finished dry product contains not less than 25% protein for whey protein concentrate, and not less than 90% protein for whey protein isolate. Hydrolyzed whey protein is processed with mild acids and warm temperatures to break the amino bonds, resulting in a protein content of about 90 to 95%.
In cosmetics and personal care products, whey protein primarily functions as a skin and hair conditioning agent. It is believed that constituents with lower molecular weight in cow’s milk whey are similar to the Natural Moisturizing Factor (NMF) found within human skin. The NMF is an expansive group of substances including amino acids, PCA, lactates, sugars, salts, urea, and peptides. All of these substances work together to keep the skin’s surface intact, supple, and hydrated. As we age, the NMF can become depleted from routine exposure to sensitizing ingredients like drying cleansing agents and denatured alcohol. The result is visibly dry, tight-feeling, flaky skin. Since whey protein is similar to NMF it is thought that topical application of this ingredient may help to restore the NMF, leading to soft and hydrated skin.
Whey protein also contains that amino acid cysteine, which is a building block for the powerful antioxidant glutathione. As an antioxidant, glutathione functions to combat free radicals, the unstable molecules that contribute to the formation of premature wrinkles and fine lines on the skin. Levels of glutathione decrease as a result of aging, stress, and toxin exposure. Using ingredients that increase the production of glutathione, such as whey protein, can better prepare the skin to fight off free radicals.
Research indicates that whey protein can also be used as a natural alternative for cosmetics packaging. According to Cosmetics Design Europe, academic studies have revealed that whey protein acts as a good moisture barrier film with acceptable mechanical integrity. It is thought that whey protein could replace harmful petroleum-based plastics with a natural byproduct.
The safety of whey protein has been evaluated and rated on EWG’s Skin Deep Cosmetic Database. According to the Cosmetic Database, whey protein is rated as a 1 on a scale of 1 to 10, with 1 being the lowest risk to health and 10 being the highest.
References: Wikipedia “Whey protein”, Dr. Axe “9 Health Benefits of Whey Protein + How to Choose the Right Product” 2017, Cosmetic Ingredient Review “Safety Assessment of Milk Proteins and Protein Derivatives as Used in Cosmetics” 2017, Cosmetics Design Europe “Whey protein found to be natural alternative for cosmetics packaging” 2011, EWG’s Skin Deep Cosmetic Database “Whey Protein”