Making Sense of Photo-aging and Its Prevention

The numerous causes of skin aging can be divided into two broad categories: intrinsic and extrinsic. Intrinsic aging results from cellular processes that occur over time and are influenced by genetics. Extrinsic aging results from environmental exposures that cause cellular damage. These exposures include: UV light, infrared and radiation exposure, air pollution, smoking, tanning beds, alcohol and drug use, stress and poor diet. Extrinsic skin aging, commonly referred to as photo-aging, presents as coarse wrinkling, irregular pigment spots and decreased elasticity.

As much as 80% of facial aging can be associated to sun exposure. Ultraviolet light has been known to cause DNA damage, free radical formation and inflammation. However, this is only part of the picture. We now know that exposure to traffic produced air pollution and soot are also big contributors to the aging process. In addition, exposure to tobacco smoke and fumes from burning trash or wood and grilling meat attribute to the signs of extrinsic aging.

Broad- Spectrum sunscreens and sun avoidance are important steps in preventing DNA damage from exposure to UV radiation. Other cosmeceutical agents have been designed to hinder the effects of UV radiation or to help with DNA repair. Antioxidants, such as polypodium leucotomos, ascorbic acid, and green tea have good data documenting their protective effects. Polypodium leucotomos (Heliocare) is an oral extract derived from ferns. Taken daily, it has been shown to reduce DNA damage after exposure to UVB. Ascorbic Acid, also known as Vitamin C, has been shown to be beneficial both orally and topically. Topical application of ascorbic acid, along with Vitamin E, resveratrol, and ferulic acid have been demonstrated to decrease DNA damage. Green tea is one of the world’s oldest and most potent antioxidants. It is rich in polyphenols- the compounds that provide our fruits and vegetables with their colors. Polyphenols help to repair UV-induced DNA damage.

In addition to topical cosmeceuticals being important in preventing photo-aging, diet is now recognized to play an important role as well. The juice and fruit of pomegranate contain a complex number if antioxidants. These have been shown to inhibit collagen breakdown and DNA damage from UVB radiation. Consumption of pomegranate juice has been found to benefit patients with carotid artery stenosis, hypertension, hyperlipidemia, and coronary heart disease. Pomegranate fruit extracts have also shown promise in cancer treatment, osteoarthritis and in slowing the progress of Alzheimer’s disease. Other foods known to be rich in similar antioxidants are dark grapes, eggplant, tomatoes, carrots, purple sweet potatoes, red cabbage, red onions, strawberries, apples, cucumber and persimmon.

It is obvious that our environment contributes to the aged appearance of our skin. This occurs because UV radiation and pollution cause DNA damage, inflammation and irregular cell production. These are some of the same factors involved in the formation of skin cancer. Therefore, we can assume that these potent antioxidants, topical and dietary, could also be helpful in preventing skin cancer development. So as mom always says, eat your fruits and vegetables.

Dr. Kevin Pinski