Chris D. Meletis, ND looks at the role skin plays in aging and health and offers tips for maintaining youthful skin.

By Chris D. Meletis, ND

Human skin can speak volumes about one’s health, and indeed is a reflection of inner health the vast majority of time. Yet, sometimes no matter what steps a person takes his or her skin looks older than desired. This can be the result of stress, excess sun exposure, insufficient antioxidants, metabolic conditions and a myriad of other factors. This does not necessarily mean that a person is not healthy on the inside, yet the skin may not fully embody that radiant glow from within. It is not necessary to passively accept this reflection of a person’s inner level of wellness.

Many people have turned to an external solution to reduce the appearance of aging. Americans spent just under $12.5 billion on cosmetic procedures in 2004. There were nearly 11.9 million surgical and non-surgical cosmetic procedures performed in 2004, according to the most comprehensive survey to date of U.S. physicians and surgeons by the American Society for Aesthetic Plastic Surgery (ASAPS). Surgical procedures represented 18 percent of the total, and non-surgical procedures were 82 percent of the total. From 2003-2004, there was a 44 percent increase in the total number of cosmetic procedures. Surgical procedures increased by 17 percent, and non-surgical procedures increased by 51 percent. Since 1997, there has been a 465 percent increase in the total number of cosmetic procedures. Surgical procedures increased by 118 percent, and nonsurgical procedures increased by 764 percent. Over 882,000 injected HA procedures were performed in 2004 alone. There are, however, a number of natural ways we can improve our skin health without going “under the knife.” In this article, I will explain how a topical preparation of pure Hyaluronic Acid (HA) can help replenish this critical skin-supporting nutrient that declines with the aging process.

Hyaluronic Acid’s Role in Health
Hyaluronic acid is a naturally occurring substance within the body that belongs to the class of compounds known as glycosaminoglycans (GAGs). In addition to HA, GAGs also include chondroitin sulfate, dermatin sulfate, keratin sulfate, heparin, and heparin sulfate. Some of the unique qualities of HA arise from the fact that it is the only GAG that is exclusively non-sulfated. Molecules of HA consist of repeating units of N-acetylglucosamine and glucuronic acid. Clinically the decline in the body’s concentration of HA with aging have long been of interest. Though this paper is dedicated to the discussion of HA and skin health, it is imperative to appreciate that drops in quantity, quality and distribution of HA across the spectrum of body tissue types occur. Therefore, it is logical that we would supplement the skin directly with HA just as we would use it internally to nourish joints, eyes, or any other body part.1

It is clearly documented in the research literature that the elastic properties of joint fluid and connective tissue decrease with age.2 Likewise a decrease in the presence of HA in eye tissue after the fifth decade is believed to contribute to increased retinal disorders.3 Furthermore older individuals with glaucoma were found to have virtually no HA in areas of the optic nerve, while similar changes were not found in either age-matched persons with normal sight, or in younger individuals. 4-5

How Age Damages Skin
The skin is the largest organ and detoxification organ in the body. It serves as dynamic packaging to contain and protect the 75 trillion cells that make up the body. It is comprised of the epidermis, the dermis below, and then the subcutaneous layer. The epidermis keeps producing new cells that push to the top of the skin surface. There are approximately 19 million skin cells on every square inch of your body. Changes that occur within the skin during the aging process decrease the ability to detoxify, convert sunlight into vitamin D, fend off infections and alter the ability of our skin to be resilient to injury.

During the aging process HA becomes more tightly tissue-associated with advancing age. In a baby, for example, 7 percent of the HA is tissue-associated, whereas the amount increases to 23 percent in senescent (aging) skin. Additionally, with age HA accumulates in deeper layers of skin over time. With increasing age, HA levels drop significantly in the epidermis, resulting in the dryness associated with aged skin.6 Clinically, this can be referred to as the “plum to prune, grape to raisin phenomenon.” This change in distribution and cellular allocation generates significant problems in wound healing and comprises the body’s ability to deal with inflammatory diseases involving the skin.7

Young skin is smooth and elastic and contains a large amount of hyaluronic acid that helps the skin look healthy. As we grow older, the ability of the skin to produce hyaluronic acid decreases and the amount of hyaluronic acid begins to fall. Since hyaluronic acid helps to bind water, the ability of the skin to retain water also declines with age. As a result, the skin becomes drier, thinner, and less able to restore itself. The loss of skin fullness also means that the skin becomes looser. This leads to wrinkling and the older appearance of the skin.

The Skin’s Layers
The epidermis protects our bodies from heat, cold, infections and buffers us from the outside environment. The condition of the epidermis determines how the skin looks and also how well the skin absorbs and holds moisture. The dermis represents 90 percent of the thickness of the skin (the epidermis above it makes up the other 10 percent). Collagen makes up 70 percent of the dry weight of the dermis. The dry part is the key, since HA hydrates the dermis so effectively that it is about 70 percent water, representing 15-18 percent of the total body water. Hyaluronic acid within the dermis normally hydrates it, providing elasticity to prevent wrinkles. Since HA chemically attracts water, topical HA (as well as oral) can help by increasing endogenous HA in the dermis or by attracting a water layer on top of the skin surface to protect against water loss.

Here’s an overview of how the dermis breaks down during the aging process:

•    The number of collagen fibers in the dermis decreases.
•    The structural attachment between the dermis and the epidermis, which is the outermost layer of the skin, deteriorates with the aging process.
•    Skin HA content decreases as we age.
•    Dermatan sulfate declines during the aging process.
•    Fibroblasts within the dermis decline by about 50 percent by age eighty.
•    UV-A and UV-B radiation from the sun are absorbed cumulatively by the skin, which can damage the dermis, causing wrinkles.

HA production typically increases during processes such as wound healing, cell migration, and blood vessel creation. During wound healing, HA is thought to open the provisional fibrin matrix in the early stages, allowing for new cells to fill the wound and remodel the tissues. Although HA is non-adhesive to cells alone, several cell surface receptors for HA have been identified on several cell types and are postulated to have several biological effects. The most common of these receptors is called CD44, which is present on vascular endothelial cells where it is thought to be necessary for building blood vessels and the protective insulating myelin layer on neurons in the nervous system. The blood vessel building properties of HA further explains its importance in wound healing. After all, it is the blood vessels that serve as the highways and byways for nutrient delivery for the repair of damaged tissues. Without the ability for cellular building blocks to be delivered all the supplementation in the world won’t get the job done as the trillion cells that comprise your body seek to maintain and regain their optimal integrity and function.

Since collagen makes up 70 percent of the dry weight of the dermis layer of the skin, it’s no surprise that collagen is essential for wound healing. Hyaluronidase breaks down both HA and collagen. Collagen is also broken down by the enzyme collagenase. As we age, our fibroblasts produce more collagenase than young fibroblasts, breaking down the body’s stores of collagen faster.

Strategies for Youthful Skin
Lifestyle factors are critical for maintaining healthy skin. Smoking can cause dryness and premature aging of the skin. Sun exposure is associated with an increased risk of skin cancer, premature aging, and hyperpigmentation of the skin, requiring a limit to sun exposure and the use of sunscreen during prolonged exposure. Clinically, exercise has been shown to help promote a radiant, glowing complexion. Optimal intake and assimilation of nutrients is also essential for promoting healthy skin. A deficiency of omega-3 fatty acids and essential fatty acids (EFAs) is often manifested as dry, flaky skin and a predisposition to inflammatory conditions, such as eczema. Vitamin A in an appropriate amount also is a crucial nutrient for healing tissues and regenerating epithelial tissues including the skin. A vitamin A deficiency can be manifested as follicular hyperkeratosis, poor wound healing, and acne. Vitamin E can prevent scarring from blemishes and incisions. Vitamin C is an important nutrient for the skin, both internally and topically, because the vitamin helps to inhibit free-radical damage and promotes collagen production. The B vitamins promote skin health and offer stress relief, with vitamin B6 being particularly helpful for preventing premenstrual acne. A zinc deficiency is common in acne and other skin problems. Finally, plenty of filtered or spring water also helps the body to remove wastes and keep the skin hydrated and healthy.

While making sure our bodies are nourished with each of the nutrients mentioned above, it is equally important to give our skin the tools necessary for rebuilding collagen and instituting cellular repair. Using a topical HA serum can have dramatic effects on skin health. Bio-identical HA, when topically applied, can buffer the decreased production of HA that occurs with the aging process. Topical HA can serve as a hydrating agent, rejuvenating skin and improving the tone and appearance by enhancing the skin’s ability to retain moisture. Applying a special HA serum that has a light, non-oily texture, can soothe skin, smooth fine lines and reduce wrinkles.

1. Ly DH, Lockhart DJ, Lerner RA, et al. Mitotic misregulation and human aging. Science. 2000;287:2486-2492.
2. Balazs EA. Viscoelastic properties of hyaluronic acid and biological lubrication. Univ Mich Med Cent J. 1968;:255-259.
3. Tate DJ Jr, Oliver PD, Miceli MV, et al. Age-dependent change in the hyaluronic acid content of the human chorioretinal complex. Arch Ophthalmol. 1993;111:963-967.
4. Gong H, Ye W, Freddo TF, et al. Hyaluronic acid in the normal and glaucomatous optic nerve. Exp Eye Res. 1997;64:587-595.
5. Knepper PA, Goossens W, Hvizd M, et al. Glycosaminoglycans of the human trabecular meshwork in primary open-angle glaucoma. Invest Ophthalmol Vis Sci. 1996;37:1360-1367.
6. Meyer LJ, Stern R. Age-dependent changes of hyaluronan in human skin. J Invest Dermatol. 1994;102:385-389.
7. Juhlin L. Hyaluronan in skin. J Intern Med. 1997;242:61-66.