Anti-aging creams belong to skincare’s most contentious and emotive sector. Each year, more and more “wonder” formulas flood the market, claiming to solve skin’s million dollar mystery – how to cure lines and wrinkles. Many formulas borrow theories and active ingredients from mainstream medicine, which lends them a scientific image. But anti-aging creams are still cosmetics – not drugs, and despite high-tech formulas, the real keys to skin defense remain surprisingly simple.
The Importance of Moisture
Skin needs moisture – that’s the bottom line. A water quota of no less than a healthy 60 per cent gives skin its smooth, plump, translucent quality, bathes cells with nutrients and keep them soft and functional. A moisturizer’s most basic job is to supplement the skin’s Natural Moisture Factor (NMF) a cocktail of moisture-attracting humectants and preservatives), help preserve fluid in the skin’s upper layers and prevent losses which hasten aging. As environmental factors such as sunlight, central heating, wind, cold and pollution all encourage moisture loss, state-of-the-art creams are designed to buffer external aggression by reinforcing the skin’s own barrier mechanisms.
In young, healthy skin natural oils and friendly flora preserve the slightly acidic mantle that keeps the barrier function of the horny outer layer intact. Overlapping dead skin cells form a scaly, water-resistant seal against dehydration. As skin ages, however, natural oil production drops and the skin surface becomes drier and less moisture-retentive. Surface scales roughen and gaps appear in the barrier, through which moisture can escape. As cell turnover also slows with aging, it takes longer for replacement cells to reach the surface and repair breaches. A malfunctioning surface barrier leaves cells in the skin’s lower layers vulnerable to damage. So, creams that help to reinforce the stratum corneum seem like the obvious answer. For, if the horny layer is doing its job, the deeper skin layers – where aging begins – are more able to look after themselves.
CREAMS CONTAINING Alpha-hydroxy acids (AHAs)
Creams containing AHAs, also known as fruit acids, bridge the gap between cosmetics and cosmeceuticals. More commonly used AHAs include citric acid, which is derived from citrus fruits; tartaric acid from grapes; malic acid from apples; and mandlic acid from cucumbers. Glycolic acid, which is derived from sugar cane, is one of the most widely used in creams because its small molecules penetrate further than other AHAs.
Creams containing AHAs exfoliate the skin by loosening the glue-like bonds that hold together the dead cells on the surface of the outer horny layer. Consistent exfoliation boosts slow cell turnover and helps other skin-care ingredients to penetrate below the surface. AHAs are also said to reduce the appearance of lines and pigment patches and boost the skin’s hyaluronic acid (moisture) quota. There is evidence that they also improve sun-tolerance up to an equivalent of SPF 25. Trials at the University of California, Los Angeles, indicate they may even encourage collagen production.
High concentrations of AHAs may cause sensitive skin reactions. Newest cream formulas hover around a “safe” 4 per cent of the total mass. However, at a recent conference, dermatologists stated that the acidity level of the AHA used was the crucial factor. Glycolic acid, for example, with a pH (acid value) of 3.5 – close to the skin’s own – is better tolerated. Even at higher percentages, AHAs work well for mature, 35-plus skin. They also help to unclog pores and regulate oily, acne-prone skin. Results are rewardingly rapid.
CREAMS CONTAINING Vitamins
Vitamins A, C and E are all antioxidants. They mop up free radicals and convert them into harmless compounds which can then be eliminated from the skin. When applied in the form of a cream, they protect against environmental damage and UV rays. They have a neutralizing effect on free radicals that is the equivalent of using SPF 2 to 3. Although antioxidants are no substitute for sunscreens, their presence in sun-protection formulas reduces the need for high levels of chemical filters which are potentially irritating to the skin. Zinc, copper, manganese, selenium and super oxide dismutase antioxidants.
In addition to their antioxidant properties, vitamins in skin creams provide other benefits. Vitamin E is an excellent hydrating surface lubricant that supplements the barrier function of the outer layer. Vitamin C plays an important role in collagen formation. Some cosmetologists suggest that Vitamin A can be turned into minute doses of retinoic acid, which can repair damaged collagen and elastin. Research is also being done into the use in creams of beta-carotene – a chemical cousin of Vitamin A – and a potent antioxidant when taken internally.
Some enzymes in the skin build and repair tissue, others break it down. Enzyme technology is an attempt to influence the skin’s natural enzymes by encouraging the function of “productive” enzymes and inhibiting the function of “destructive” enzymes, which may become over-active due to age and sun damage. Some enzymes are also excellent exfoliants. They dissolve protein and fats, and help to loosen dead surface cells. Their action is less irritating than that of AHAs, so they make good alternatives. Products with pineapple and papaya extracts are examples of enzyme-based formulas. Heather and honey enzymes are also used in firming creams.
Do cells communicate? If they do, intercellular enzymes are the messengers. Cosmetologists theorize that signals received by one set of cells set off a chain reaction, enabling the right cells to turn up in the right place at the right time. If, for example, surface cell are exfoliated, new cells are stimulated to migrate upward to take their place. So an important part of enzyme technology is to keep cells talking. Enzymes found in plant extracts are usually useful for this purpose.
Liposomes were originally used in medicine to aid the penetration of injected drugs, so their use in skin creams had contentious beginnings. Microscopic, lipid spheres (soya oil and ceramide are common ingredients), these hollow carrier molecules can be filled with other skin-care ingredients, which are then delivered to target sites in the skin. Early cosmetic liposomes were deemed unstable and useless – nothing more than oily lubricants that melted on the skin’s surface. After countless refinements, however, it does seem that the liposomes of today – newer, tinier and more stable molecules – can access the lower layers of the epidermis. Most skin creams contain them.
Does skin breathe? Oxygen is the key to healthy cell regeneration and skin metabolism. Medical opinion is that skin cells receive oxygen via the bloodstream and not through the pores of the skin. An increasing number of cosmetologists, however, suggest that oxygen can be introduced into the skin via specially constructed liposomes. Sceptics hold that too much oxygen generates free radicals. Champions assert that oxygen creams are like a breath of fresh air to dull skin (especially smoker’s skin) with poor circulation. The skin aerobic debate is set to continue for many years to come.