Doctor Rhonda Low shares how to protect yourself from a summer sunburn
If you think Vancouver’s oft-overcast skies will protect you from burning, think again. Local rays are strong enough to damage your skin even on cloudy days. Lucky for you, Dr. Rhonda Low is here to answer your FAQs about sunscreen. How often should I apply sunscreen? How much do I need? What do SPF and SPF numbers really mean? What ingredients should I look for? But isn’t some sun good? What can I do if a little damage has already been done?
It’s recommended that sunscreen be applied 15 to 30 minutes before heading outside and then re-applied every two hours or immediately after swimming – even if the product is waterproof.
Studies show that most people only use about 25 per cent of the recommended amount of sunscreen. For an average-sized person, you need to use about a quarter of a regular-sized bottle (approximately 180 ml), which is about a golf ball-sized amount or a shot-glass full.
SPF stands for “sun protection factor,” and is derived under controlled laboratory settings. The number indicates how much additional time you can stay in the sun without burning. For example, an SPF of 30 would protect you 30 times longer than if you went without sunscreen, so if you normally burn after 10 minutes of being out in the sun, an SPF of 30 would protect you for up to 300 minutes, or around five hours.
As a rule, sunscreens with fewer ingredients tend to be better for sensitive skin, but the right ingredients are key. Good sunscreens block both UVA and UVB rays, are less likely to cause skin irritation and are water-resistant. To help protect against the harmful UVA rays that cause aging, wrinkles and skin cancer, look for products that contain a combination of micronized titanium dioxide, Parsol 1789 or Mexoryl XL.
The U.S. National Institute of Health suggests the average person only needs about five to 30 minutes of unprotected summer sun a couple of times a week in order to manufacture sufficient levels of vitamin D in their body. Since most of us tend not to put on enough sunscreen or diligently renew on schedule, the vast majority will get enough vitamin D. Like everything, we have to balance the benefits of using sunscreen to prevent skin cancer, wrinkles and other signs of aging against the potential risk of a possible vitamin D deficiency. The way I see it, getting enough vitamin D from the sun doesn’t take much and you can always top up with a supplement – but there’s no magic pill or easy way to prevent skin cancer and wrinkles (contrary to what some marketing companies may have you believe).
There is increasing evidence suggesting topical antioxidants – those containing vitamin C and E – may increase the efficacy of your sunscreen by preventing and even reversing sun damage. But to be effective, they need to have at least one per cent of vitamin E in the D-alpha-tocopherol form and the vitamin C must be formulated as 15 to 20 per cent L-ascorbic acid. To date, oral ingestion of these vitamins has not been shown to be very effective in providing sun protection and should not replace the use of a good sunscreen.
If you think Vancouver’s oft-overcast skies will protect you from burning, think again. Local rays are strong enough to damage your skin even on cloudy days. Lucky for you, Dr. Rhonda Low is here to answer your FAQs about sunscreen.
How often should I apply sunscreen?
How much do I need?
What do SPF and SPF numbers really mean?
What ingredients should I look for?
But isn’t some sun good?
What can I do if a little damage has already been done?