THE BALANCED LIFE | The truth about sunscreen |
How to choose your sunscreen? In a conclusive study conducted on four of my male cycling friends, it seemed to be due to the color of the tube.
Ten days ago, during our week of July to May and during a beginner drive-to ride in Cayuga, none of us had thought to bring sunscreen. All that was available were a few, mostly sold out, dollar store tubes of sunscreen lotion that had been wintering in my van. One tube was a cute pink, the other a more masculine orange. Both were labeled SPF 30 in bold enough letters for all of us to read without our glasses. When the two tubes were offered to the guys, each chose the orange with no questions asked about the ingredients or the protection.
Why should we care?
Going beyond the color of the tube to understanding sunscreen, what it can and cannot do, the different types available, and the pros and cons of each, can make significant long- and short-term differences in health. of your skin, and how likely you are to get one of the three most common types of skin cancer: squamous cell carcinoma, basal cell carcinoma and melanoma. The Canadian Cancer Society estimates that in 2022, some 9,000 Canadians will be diagnosed with melanoma, the most common but least deadly form of skin cancer. Twelve hundred will die, 770 men and 440 women.
Melanoma starts in our melanocyte cells, most of which are located in our skin. Cancer occurs when melanocyte cells grow out of control and turn into tumors that most often appear on the backs of men and on the backs and legs of women.
The US National Cancer Institute says the rate of new cases has tripled since the 1970s and cites ultraviolet A (UVA) radiation and severe sunburn as major contributing factors.
To choose your sunscreen wisely, it is important to know that the sun emits two distinct types of ultraviolet light. Each reacts differently with our skin and causes different long-term health effects.
UVA light has a longer wavelength that can penetrate the dermis, our thickest layer of skin. Skin aging, wrinkles and immune system suppression can result from unprotected exposure to UVA rays.
UVB rays have a shorter wavelength and are the rays associated with burning the top layer of the skin. The resulting sunburn, and therefore ULV rays, play a key role in the development of skin cancers and permanent skin damage over time.
The protective ingredients found in sunscreen lotions are classified into two main groups.
Sunscreen that contains physical blockers protects us by reflecting and scattering UV rays away from our skin. Sunscreens that use chemical blockers protect by absorbing the sun’s UV rays and converting them into heat.
Physical blockers generally include two active mineral ingredients, zinc oxide and titanium dioxide, which are classified by Health Canada as natural ingredients. Sunscreens that contain only physical blockers can be identified by an eight-digit Natural Product Number (NPN) on their packaging.
A recent trend in the manufacture of sunscreens containing physical blockers is to reduce, or micronize, their mineral compounds into nanoparticles. This process facilitates the application of sunscreen and allows it to disappear into the skin, eliminating the white and greasy residue of old sunscreen lotions. Studies have shown that these nanoparticles do not enter our bodies beyond the skin or into our bloodstream, so they are unlikely to create additional health risks.
Sunscreens using chemical blockers such as avobenzone, homosalate, octocrylene, octisalate, octinoxate and oxybenzone are classified by Health Canada as containing medicinal ingredients and carry an identification number of the medication (DIN) on the label similar to other over-the-counter medications. Some small studies conclude that these chemicals can pass through our skin, as evidenced by the high concentrations found in human blood, urine, and breast milk. This is especially common in people who apply large amounts of sunscreen to their skin.
Health Canada agrees that more studies are needed, but at this time they are following US FDA guidelines which state that taking sunscreen is safe and using all the chemical ingredients currently present in sunscreens is safe.
Sunscreens labeled “broad-spectrum” contain both physical and chemical blockers, meaning they’re effective at blocking both UVA and UVB rays, maximizing overall protection from the sun. In Canada, broad-spectrum sunscreens are labeled with a DIN number.
It is important to recognize that the SPF rating of a sunscreen is not an indication of its ability to protect against all types of radiation.
SPF is a relative measurement that compares how long it will take for unprotected skin to burn against a specific sunscreen when applied as directed on its label. SPF numbers therefore represent a protective factor related to sunburn only, and not to other types of skin damage such as accelerated skin aging, DNA cell damage, free radical generation and cancer. skin. If you reapply your sunscreen at two-hour intervals as recommended, an SPF of 30 is considered sufficient. Ratings above SPF 60 have more to do with marketing than protection.
Sunscreens advertised as moisture or sweat resistant, often aimed at athletes, should also be used with an understanding of their true capabilities.
No sunscreen is 100% waterproof and labels in Canada generally recommend an effective limit of 80 minutes. All sunscreens, including those that are moisture resistant, should be applied about 10 to 15 minutes before going out in the sun or entering the water. Using towels to dry off, or the sleeve or back of a bicycle or golf glove to absorb sweat will also wash out most sunscreens, reducing protection.
Does using sunscreen create a risk of vitamin D deficiency? Science says no. During peak sunlight hours, between five and thirty minutes of sun exposure each day will provide humans with enough vitamin D. It is highly likely that even the most conscientious sunscreen users will find themselves exposed unprotected for an extended period of time. enough every day.
For those who hike, bike, paddle, or participate in any other sport that puts them near mosquitoes, ticks, and black flies, sunscreen and insect repellent can be safely used together. Apply your sunscreen first and leave it on for 10-15 minutes before applying your choice of insect repellent on top.
Unused sunscreen deteriorates over time. On the tubes in our house, the expiration date is stamped into the plastic at the bottom where the tube is heated and crushed for sealing purposes.
Now that you’ve chosen the most protective sunscreen, what’s the best way to use it?
As above, apply approximately 10-15 minutes before exposure. Sunscreen breaks down in light and quickly loses its effectiveness, so reapply every two to four hours, or more often if you sweat or swim.
In Southern Ontario, between 11 a.m. and 3 or 4 p.m. is when the sun is at its brightest and extra care should be taken to apply enough sunscreen.
It is important to apply the right amount of sunscreen. Health Canada recommends one teaspoon per arm, leg, front, back and face or neck. This equates to about seven teaspoons to cover all exposed skin areas on our bodies, or 35 milliliters. If metric conversion isn’t your forte, using a shot glass full of sunscreen will do a full job.b.
Turns out, choosing a broad-spectrum sunscreen, with an SPF of at least 30, that’s water and sweat resistant, and that’s not a year past its expiration date might have been smarter than just going for the orange colored dispenser. Live and learn. ◆