Skin

The awesome organ and the science behind skincare

Ask people what the largest organ in the body is and most will not think of skin. However, this elastic and dynamic organ is the biggest and one of the most important structures. Skin not only protects our flesh and inner organs from cuts, scrapes, and burns, but also waterproofs us, repairs early sun damage, and regulates our body temperature. Most interestingly of all, it plays a large role in our social lives. Skin is the only organ whose appearance is highly public, prized, and preened. In the United States alone, 8 billion dollars are spent annually on cosmetics. The skincare industry is fraught with false advertisements. These range from ingredients with limited research for backing up their claims to products that cause more damage than good. With so many choices of products and thousands of anecdotal reviews, what is the true science behind skincare?

To begin, some foundational knowledge about skin is needed. This organ is made up of tightly knit cells called epithelial cells. These tiny units join together into sheets with the help of a multitude of proteins, which give the structures flexibility, waterproofing, and the capacity to communicate. Sheets upon sheets of epithelial cells layer on top of one another to form the dermis (the deeper layer of your skin) and the epidermis (the visible outer layer).

In the skin, cells specialize within their layers to form pores. For example, some dermal cells become hair follicle cells, while others specialize into oil gland cells that coat the hairs with sebum. Skin cells are also always aging and changing. Though it seems like your skin and pores look the same, the turnover rate for cells is quick compared with other cells in the body. Skin cells migrate to the outer surface and detach from the sheets when they can no longer sustain a bond with living cells. In most normal cases, skin cells simply fall off unnoticed. However, when they become trapped among their cell neighbours, problems arise.

Acne is one of the most prevalent skin conditions and tends to occur in teenagers and young adults. The signs are obvious: red pimples (papules), whiteheads (pustules), blackheads, and painful bumps underneath the skin called cysts or nodules. Though acne is often thought to be the product of dirtiness, pimples cannot be scrubbed away with cleansers. The true cause of acne can be varied: bacterial proliferation, hormonal changes, or a combination of both. The bacteria in the first case are called P. acnes, and they are a naturally occurring microbe on the skin. These bacteria often grow out of control during puberty due to the over-production of sebum that comes with the raising of androgen levels. Androgens are male sex hormones present in all humans, and their side effects include stimulating oil production and increasing skin inflammation. With more sebum in the pores, P. acnes can proliferate and become trapped inside pores in a clump of skin cells and oil. The resulting clog is called a comedone. In the second case of hormonal acne, the increase in androgens during puberty and progesterone before menstruation can cause an excess of sebum. The natural exfoliation of cells from the epidermis may not be functioning optimally; therefore, the sebum-sticky dead cells collect in the pore, causing inflammation.

How does one remove these comedones? For immediate relief of visible whiteheads, a hot cloth over the comedone can soften the oil for removal. However, the underlying cause of the pimples cannot be treated this way. When it comes to bacterial acne, the answer is typically benzoyl peroxide. This topical disinfectant can be bought over the counter at 2.5, 5, and 10 percent concentrations. Benzoyl peroxide kills P. acnes and tames breakouts in the long term. Another option is salicylic acid, a derivative of willow bark extract. Its better-known precursor, aspirin, is often touted as a home remedy for pimples. Many online sources suggest crushing aspirin pills and mixing them with water. The pure form of aspirin, though, has the potential to dry and irritate the skin, making it a dubious treatment. Salicylic acid, on the other hand, is often already packaged into over-the-counter creams in 1 to 2 percent concentrations. This acid is a chemical exfoliant that can dissolve oil plugs and fix the shape of the pore lining over time, improving oil flow. Most people think of exfoliation as scouring with a washcloth or gritty scrubs. However, manual exfoliation only touches the surface of the skin and cannot reach the source of the problem: the pores. It also irritates the skin, causing microtears. Therefore, if exfoliation is the treatment of choice, chemical exfoliation is more targeted and effective. The only limitation of salicylic acid products is the pH range required for proper exfoliation. pH is a measure of acidity or basicity in a liquid. Salicylic acid only works within an acidic pH range of 3 to 5. Most products have a pH far above 5, so it is important to check online resources for the pH of specific products.

With this new knowledge, however, it is important to note that other ingredients make a difference in the efficacy of skincare products. Toners, creams, masks, and other leave-on products should include antioxidants such as Vitamin E (tocopherol), Vitamin C (ascorbic acid), and squalene, as well as ingredients to help with cell communication, such as niacinamide. For those with sensitive skin, soothing ingredients such as bisabolol and allantoin help tone down redness. These components bolster the skin’s sun-damage repair mechanisms and speed up the healing of dark spots left over from past pimples.

Some ingredients should be avoided completely, such as denatured alcohol and essential oils (bergamot, linanool, limonene, lavender, sandalwood, etc.). These ingredients often add to the texture and fragrance of products, making them more aesthetically pleasing. However, they have been proven to cause short-term irritation by drying out the skin, while also affecting skin in the long term by damaging cells’ ability to regenerate. To put denatured alcohol into perspective: it is used as rubbing alcohol to kill bacteria in households and laboratories alike. Considering its potency in killing cells, it would not make a good skincare ingredient.

How does one choose ingredients? Take the time to look at the ingredient list of new skincare products. Due to FDA regulations, most ingredient lists show ingredients in descending order of quantity. Therefore, keep an eye out for the ingredients that come first. To fill in any unknowns, online dictionaries have been made to sort ingredients by function and potential for irritation. Not only is it an interesting exercise to find ingredients you recognize, but having this knowledge proves useful time and time again. In the Internet era of self-care, misguiding advice and unfounded fads are at an all-time high. The feeling of health and wellness can be subjective, but thankfully, skincare can be backed by objective science.