Nutritional Lipids for Skin Support

Fat may still be a relatively taboo word in the food formulation arena, but in the area of skin care and nutricosmetics, lipids play an essential role in the health of the skin. They are particularly important in the stratum corneum, the permeation barrier with hygroscopic properties that includes a number of lipid layers.

As noted in the Delivery System Handbook for Personal Care and Cosmetic Products (William Andrew Inc., 2005), lipids can be broadly classified as simple lipids (i.e., long chain fatty-acids or –alcohols), phospholipids, sphingolipids, and complex or miscellaneous lipids. In the epidermal stratum corneum, the principal lipids include ceramides, cholesterol and saturated fatty acids.

Ceramides are composed of sphingosine and a fatty acid, and are one of the component lipids that make up sphingomyelin, a major lipid in the lipid bilayer. Nava Dayan, Ph.D., Lipo Chemicals, said ceramides in particular play a key role in establishing the barrier function of the stratum corneum. “Being major lipid constituents of the intercellular lamellar sheets, ceramides account for 40 to 50 percent of the stratum corneum lipids by weight,” she added. “Ceramide NS, commonly referred to as ceramide 2, is incorporated into topically applied formulation to treat dry mature skin. It can be metabolized and serve as a precursor for other molecules from the ceramide family.” She noted nature-identical ceramides can be converted to other sphingolipids to assist in repairing dry skin and enhancing skin protection.

While ceramides have gained some interest among formulators, consumer attraction to more “natural” options is increasingly manifesting in the incorporation of natural oils as ingredients for cosmetic formulations, both as emollients and sources of skin nutrients.

“The use of nutritional lipids to serve multiple functions in cosmetic formulations is becoming increasingly popular,” said David Chance, sales and marketing manager, Sanmark. “There is a great and growing interest in using natural products, which are non-synthetic. Nutritional lipids have similar compositions to skin lipids; they are therefore more compatible to human skin and can improve sensory properties of skin care products if used properly.”

In addition to compatibility with the natural skin layers, natural lipids further contain high levels of nutrients such as vitamin E and phytosterols, as well as essential fatty acids (EFAs). John O’Keefe, director, and Carla Danca, technical sales representative, AAK Lipids for Care N.A., along with Jari Alander, technical director, AAK Sweden, noted: “From a skin care viewpoint, omega-6 fatty acids are the most important ones to consider. Omega-6 fatty acids are incorporated in skin lipids and the epidermal barrier. Omega-6 is a precursor to many important products in the skin including ceramides, which are important for the moisturization and barrier function of the skin. A proper balance between omega-6 and omega-3 also contributes to maintain a good health status of the skin by regulating the inflammatory pathways in the skin.”

In fact, AAK developed its new Lipex Omega range of products to bring optimal content of omega-6 and omega-3 with technology that enhances the stability and functionality for advanced formulation. The products are based on different natural oils—Gold of Pleasure (Camelina oil), Passion Flower, and Evening Primrose—to support a wide variety of creativity in formulation.

Gold of Pleasure oil, for example, delivers between 30 and 40 percent omega-3 and approximately 20 percent omega-6, along with the naturally protective antioxidant tocopherols (vitamin E) Chance added oils such as evening primrose and borage deliver gamma linolenic acid (GLA), which has been shown to be beneficial in reducing skin inflammation and protecting against eczema. He noted, “both topical application and dietary supplements of EFAs have been shown to restore dry skin conditions.”

Another important group of natural lipids are the phytosterols, which are important hormone and vitamin precursors that also influence the stability and barrier properties of membranes, according to information provided by AAK. The company noted phytosterols are found in vegetable oils in concentrations ranging from 0.1 percent to 1 percent with oils such as canola and wheat-germ frequently used in this area. In addition, phytosterols play a functional role in the skin barrier, strengthening the lipid barrier and improving dry skin.

While natural lipids are beneficial for the skin, they are also particularly susceptible to oxidation. O’Keefe, Danca and Alander said formulating for high stability in topical formulations can be challenging if a company isn’t starting with high quality oils. “Many of the nutritional oils are polyunsaturated, and use of poorly refined oils can lead to short shelf life, unattractive smell, or discoloration in the finished formulation,” they explained. AAK noted it has specialty technology to ensure stability of its lipid ingredients, as well as assistance with related ingredients that can aid in incorporating oils into water-containing formulations.

Chance agreed there are several important issues to address to ensure the efficacy of a finished product: “The complexity of formulation, the concentrations of lipid bioactives, the degree of saturation or unsaturation of the lipids, their organoleptic properties and the chain length of the fatty acids all contribute to the final result of the product and affect the physicochemical properties, and are, in turn, related to how effective the product may be in providing a health benefit.”

Another new technology breakthrough involves the use of oilbodies, storehouses within seeds for emollient oils, antioxidants and moisture barriers. SemBioSys’s Botaneco division is using a patented process, DermaSphere, to isolate the oilbodies from the seeds without using traditional crushing methods; the process involves no chemicals to capture the liposomes, thereby creating a natural, exceptionally mild material that serves as an emollient, emulsifier and moisturizer in formulation. This oil-in-water emulsion naturally delivers moisturizing oils, emulsifying proteins and phospholipids. Botaneco officially released a branded line of oilbody-based ingredients, Hydresia™, in late 2007. The company is working with potential marketing partners to encourage the use of Hydresia as a base emulsion.

Ultimately, the use of natural lipids in skin care has global appeal, according to O’Keefe, Danca and Alander. They noted: “Coming from nature, natural lipids support the important ideals of sustainability and renewability. When developing products for today’s consumer, leading companies recognize the needs of their audience and the global environment. By using natural ingredients, formulators show that they care about the consumer’s personal wellbeing, while protecting the environment in which they live.”