Photo-Aging: Not just any sunscreen will do!
As the long-awaited arrival of the summer sun lifts spirits, sprouts tree buds and blooms countless flowers, remember there can be a dark side to the light. In a previous article I discussed the ill effects of sun exposure on the development of skin cancer. It’s certainly startling that 4 million new skin cancers are diagnosed every year and half of us will have skin cancer within our lifetime! However, this is only one of the negative effects of solar radiation – it also has a profound impact on the premature aging of our skin.
Photoaging or solar elastosis, is becoming an ever increasing concern for young adults who love outdoor recreation. The main culprit is ultraviolet radiation (UV). Among the many wavelengths of light emitted by the sun, the UV spectrum is the most harmful. The UV spectrum is divided into UV-A (320-400 nm wavelength), UV-B (290-320 nm), and UV-C (100-290 nm). For years, the UV-B spectrum has been thought to be the main source of solar damage. One reason for this is because it’s the most visible damage… UV-B damage takes the form of a sunburn. It’s also worth noting that SPF classifications only apply to UV-B rays.
Recent studies have shed new light on other components of the sunlight that, while not directly causing immediately visible results like a burn, have other harmful effects on the skin. UV-A is now known to be a major player. In fact, the tanning component of sunlight exposure is mediated by UV-A exposure. This results from darkening of existing pigment (melanin) in the skin, stimulation of new melanin production, and increasing the number of pigment producing cells (melanocytes). In other words, exposure to UV-A rays will damage and age your skin.
The photo-aging effects of UV-A on the skin are:
1. Thickening of the Epidermis (giving the skin a thick, leathery appearance)
2. Thinning of the Dermis (the underlayer of the skin)
3. Degradation and decreased function of the stretchy elastin within the skin
4. Collagen breakdown and resorption
5. Decrease fibroblast activity (important because these cells replace collagen and elastin)
The key to avoiding accelerated, sun-mediated aging are simple and don’t require you to become a recluse during the summer months. First, always use sunscreen. However, not just any sunscreen will do. Spend a little more on a good product with both UV-A and UV-B protection. These will often contain a substance called Avobenzone, the most common UV-A protectant.
Second, avoid the peak times of UV exposure, typically between 10:00 am and 2:00 pm. Third, cover vulnerable areas such as your face or your husband's increasingly exposed scalp with a hat. Fourth, be aware that sun exposure is relentless; cloudy days offer no shelter, trips to the store occur under the sun's watchful eye, and reflection from the water or ground can be significant. Finally, protect the kids as well, because the solar aging process starts as soon as we get exposed. Try to keep them covered at all times with good sunscreen and hats!