Skin aging occurs through two primary processes: intrinsic aging and extrinsic aging. Intrinsic aging is influenced by chronological and genetic factors—essentially, the natural passage of time and inherited traits. In contrast, extrinsic aging results from environmental and lifestyle factors, such as sun exposure and smoking.

When examined under a microscope, intrinsically and extrinsically aged skin show distinct differences. These microscopic structural changes are reflected in their visible appearance to the naked eye. Intrinsically aged skin appears thinner and finely wrinkled, while extrinsically aged skin has a coarse, leathery texture with deeper wrinkles.

The photograph referenced, originally published in the New England Journal of Medicine, illustrates this contrast vividly. It features a 66-year-old truck driver whose left side of the face experienced prolonged sun exposure through his truck window over 28 years. The right side, affected only by intrinsic aging, is markedly different from the sun-damaged, extrinsically aged left side. This type of damage is referred to as photoaging.

What Can Be Done?

Unfortunately, reversing intrinsic aging remains a challenge, as folklore’s “fountain of youth” has yet to be discovered. Genetic factors, of course, are beyond control—though “choosing the right parents” is humorously suggested.

However, extrinsic aging is preventable to a significant extent.

Sunlight: The Primary Culprit

The sun emits UVA and UVB rays, both of which alter the skin’s structure:

• UVB rays penetrate the skin superficially, causing sunburn.
• UVA rays penetrate deeper, contributing to photoaging.

Shielding your skin from UV radiation is crucial. Broad-spectrum sunscreen that protects against both UVA and UVB is essential. To use sunscreen effectively:

• Apply it 15 minutes before sun exposure.
• Reapply every two hours or immediately after rubbing the skin or getting wet.

Remember, sunscreen is still necessary on cloudy days or under shade, as UV rays can reflect off surfaces and penetrate through clouds. Additionally, UVA rays can pass through glass, making protection vital even indoors near windows.

For those seeking a simpler (albeit drastic) solution, living in a cave and avoiding sunlight entirely could be an inexpensive alternative!