By: Dr. Sanjana Shivshankar, MBBS, MD (DVL), FRGUHS, Director&chief dermatologist, Medical Adviser for Entod Pharmaceuticals
Since childhood, we’ve been told that morning sun is good for our health, while the harsh midday sun should be avoided. With summer heat at its peak, it’s important to understand this difference. Sunlight is vital for skin, bone health, and immune function. However, UV rays can be harmful, leading to sunburn, premature aging, and an increased risk of skin cancer. Balancing sun exposure is key to maintaining healthy skin while minimizing the harmful effects of UV radiation.
The benefits of sun exposure
Sunlight stimulates the production of vitamin D, which is synthesised when UVB rays interact with the skin. Vitamin D is vital for calcium absorption, promoting strong bones and teeth, and plays a role in immune system regulation. Deficiencies in vitamin D can lead to rickets in children and osteomalacia in adults, conditions characterised by weakened bones.
Beyond vitamin D production, moderate sun exposure has been linked to improved mood and mental health. Sunlight boosts serotonin levels, which can help alleviate depression and anxiety. Moreover, some studies suggest that limited sun exposure may reduce the risk of certain cancers, such as colon and breast cancer, though the evidence is not conclusive.
The risks of UV exposure
Despite these benefits, the risks associated with UV exposure are significant. UV radiation, particularly UVA and UVB rays, can penetrate the skin and cause direct damage to DNA. This damage can result in mutations, which may lead to skin cancers, including melanoma, basal cell carcinoma, and squamous cell carcinoma.
UV exposure is also the primary cause of photoaging, which manifests as wrinkles, loss of skin elasticity, and pigmentation changes. The cumulative effect of UV damage over a lifetime can lead to the breakdown of collagen and elastin fibers in the skin, accelerating the ageing process.
Moreover, excessive sun exposure can lead to sunburn, an acute inflammatory response to UV damage. Repeated sunburns, especially during childhood, substantially increase the risk of developing skin cancer later in life.
Balancing sun exposure
Given the benefits and risks, it is crucial to find a balance that allows for sufficient vitamin D production while curtailing DNA damage. Here are some guidelines to achieve this balance:
- Moderation is key: Aim for moderate sun exposure, typically around 10-30 minutes several times a week, depending on your skin type and geographical location. Those with lighter skin need less time to produce adequate vitamin D compared to those with darker skin.
- Use sunscreen: Apply broad-spectrum sunscreen with an SPF of at least 30 to exposed skin when spending extended periods outdoors. Reapply every two to three hours. Sunscreen helps block harmful UV rays while still allowing some UVB exposure necessary for vitamin D synthesis.
- Wear sunglasses: Avoid direct sunlight during peak hours, between 10 am and 4 pm, when UV radiation is strongest. Wear sunglasses with complete UV protection.
- Opt for protective clothing: Long sleeves, wide-brimmed hats can provide physical barriers against UV rays. Choose fabrics with a tight weave for better protection. Light-coloured clothing can also help reflect sunlight and keep you cool.
- Regular skin checks: Perform regular self-examinations of your skin for any new or changing moles or spots. Early detection of skin cancer can lead to more effective treatment.