UV protection and sunscreen: Investing in lifelong skin health

Hannah Rezaian, DO is a primary care physician at Inova 360° Concierge Medicine. As a board-certified internal medicine and geriatrics specialist she focuses on helping patients maximize their health and wellbeing through every stage of life – understanding the whole person and partnering to create plans that align with individual goals.

Many of us appreciate the benefits of sunshine. Sunlight helps regulate circadian rhythms, supports vitamin D production and can positively influence mood and overall wellbeing. However, cumulative exposure to ultraviolet (UV) radiation remains one of the most significant and preventable causes of skin aging and skin cancer.

UV radiation reaches the earth mainly as ultraviolet A (UVA) and ultraviolet B (UVB) rays. UVB is responsible for sunburn and can lead to development of skin cancers. UVA penetrates more deeply into the skin, accelerating collagen breakdown, pigmentation changes and the visible signs of aging. Both contribute to long-term skin damage.

When selecting sunscreen, dermatologists recommend choosing a product that is broad-spectrum, provides protection against both UVA and UVB radiation, has an SPF of at least 30, and is water-resistant when used during outdoor activities, exercise or swimming.

The sun protection factor (SPF) measures protection against UVB radiation. While SPF 30 blocks approximately 97% of UVB rays and SPF 50 blocks about 98%, proper application is just as important as the SPF itself. One of the most common mistakes is applying too little sunscreen. Most adults require approximately one ounce, or about a shot-glass full, to adequately cover the entire body. For the face and neck alone, roughly one teaspoon is recommended.

For optimal protection, apply sunscreen 15 to 30 minutes before sun exposure and reapply at least every two hours. Reapplication is also necessary after swimming, excessive sweating or towel drying, even when using water-resistant products.

Sunscreen should be viewed as only one component of a comprehensive sun protection strategy. Additional measures include seeking shade during peak UV hours, wearing a wide-brimmed hat, using UV-blocking sunglasses and choosing sun-protective clothing with a high ultraviolet protection factor (UPF).

The bottom line is simple: protecting your skin today pays off for decades to come. Daily use of a broad-spectrum sunscreen, combined with thoughtful sun-protective habits, remains one of the most effective ways to preserve skin health and reduce the risk of skin cancer.