According to the American Academy of Dermatology, the number one cause of melanoma (skin cancer) is exposure to natural and artificial ultraviolet (UV) light, the same light you get from tanning beds and the sun’s rays.
Ultraviolet light is light from the sun that is invisible to the naked eye. There are two types of UV rays that we are concerned about: UVA and UVB.
UVA rays account for the majority (95%) of UV radiation, are relatively constant all year round, this damage is usually an accumulative effect and invisible to the naked eye. UVA lights have a longer wavelength, they penetrate deeper into the skin, cause damage to DNA, and break down collagen and elastin. This kind of rays associated with premature aging of the skin and cancer. They are so long that they are able to penetrate your skin even by passing clouds and your car window.
UVB rays account for less than 5% of total UV radiation and are stronger in the summer. They have a shorter wavelength and associated with sunburn and the tent of the skin. These rays can’t penetrate your skin on a cloudy day or through the glass.
Protection against both UVA and UVB is crucial!
Sunscreen works to protect humans from these two different kinds of UV lights. They work in combination with biological photoprotection (melanin production) by absorbing or scattering UV rays and preventing them from reaching DNA and other skin components that are prone to damage from UV radiation. A study published in September 2018 in JAMA Dermatology reveals that regular sunscreen use in young adults is strongly associated with a reduced risk of melanoma. Similarly, a long-term study published in the Journal of Clinical Oncology suggests that regular sunscreen use may prevent melanoma in adults.
That said, not all sunscreens are created equal, working the same way, and not all of them are safe for us. Let’s have a look:
Sunscreen can be made of chemical filters, mineral filters (also called physical sunscreens), or combination of the two.
Chemical sunscreens are the most popular these days. Products with chemical UV filters typically include a combination of two to six of the following active ingredients: oxybenzone, avobenzone, octisalate, octocrylene, homosalate, and octinoxate.
They absorb into your skin and wait for the UV lights to show up. Once the UV lights penetrate the skin, the sunscreen molecules create a chemical reaction in which UV lights are converted to heat, and the heat dissipates from the skin.
Chemical filters can offer protection against the UVA and/or UVB spectrums. They can come in lotions and sprays with no white residue, but you will need to reapply them more often than you would with a physical option.
Mineral (physical) sunscreens create a physical barrier on your skin, like a shield, that reflects UVA and UVB rays. These types of filters use zinc oxide and/or titanium dioxide. The efficiency of physical sunscreen filters largely depends on the correct application. Mineral formulas can be more difficult to spread on your skin and they also leave behind white cast, but usually, last longer than chemical formulas.
Many products on the market combine mineral and chemical filters for better protection.
How do we know about the effectiveness of a sunscreen?
You probably have heard about SPF, but what about UVA-PF, Broad-spectrum,and PA?
The effectiveness of sunscreen has traditionally focused on SPF and has been accepted as a world-wide standard. SPF stands for Sun Protection Factor.
As per Skin Cancer Foundation, “The SPF number will tell you how long the sun’s UV radiation would take to redden your skin when using the product exactly as directed versus the amount of time without any sunscreen. So ideally, with SPF 30 it would take you 30 times longer to burn than if you weren’t wearing sunscreen.”
And now is the tricky part: SPF measures protection against UVB rays only(!!!). But, protection against UVA rays is critical (UVA can lead to cancer, remember?), so what can we do to protect ourselves from UVA rays as well?
Unlike SPF, there is no internationally universal method for measuring a sunscreen's protection against UVA radiation. However, any sunscreen labeled as broad-spectrum in the US has to contain both UVA and UVB protection. Even though this alone does not tell us how good the UVA protection is, it is better than a non-broad-spectrum sunscreen.
Some measurement methods can help us to determine a sunscreens UVA protection, for example, UVA-PF.
UVA-PF stands for UVA Protection Factor and is a measure of how much a sunscreen offers UVA protection. But how can we know a sunscreen UVA-PF rating? Unfortunately, unless a sunscreen brand advertises its UVA-PF rating, there is no way to tell what the exact UVA-PF is.
Here is my piece of advice: Did you know that cosmetic regulation in the EU is much stricter than in the US or Canada? From my perspective, it makes sense to use sunscreen products that have been approved by the EU. Being said that, If a sunscreen contains on its label the UVA Seal (i.e. the letters U, V, and A in a circle) or if it labeled as Broad-Spectrum in the EU, then we know that the UVA-PF is at least 1/3 of the SPF value. For example:
· SPF 15 = UVA-PF 5
· SPF 30 = UVA-PF 10
· SPF 50 = UVA-PF 16
It also shows, in order to get more than 15 of UVA-PF you better use SPF 50.
Even though I’m trying to keep this article as short and simple as I can (because I am hoping you will read it till the end), I would like to mention the PA System as well. This method used by the EU, and it indicates by pluses. More pluses – better UVA protection. For example:
· PA+ = UVA-PF between 2 and 4
· PA++ = UVA-PF between 4 and 8
· PA+++ = UVA-PF more than 8
· PA++++ = UVA-PF more than 16.
To keep it simple, just remember we are looking for four +!
Chemical vs. Mineral sunscreen - Which is better?
The FDA began to consider sunscreen safety in the late 1970s without reviewing the evidence of their potential hazards. According to the agency, nearly all of these sunscreen active ingredients have limited or no data characterizing their absorption. But, after being behind the game for decades, the Food and Drug Administration has been taking positive steps to improve the state of available sunscreens. While the agency continues testing, the COVID-19 situation is delaying the finalizing of rules that would make sunscreen safer.
In 2019 and 2020, FDA published two studies showing that the ingredients oxybenzone, octinoxate, octisalate, octocrylene, homosalate and avobenzone are all systemically absorbed into the body after a single use (Matta 2019, Matta 2020). The FDA also found that the sunscreen ingredients could be detected on the skin and in blood weeks after application ended (Matta 2020).
These findings are troubling because they show that sunscreen chemicals are circulating in the blood for a long period after application.
As of today, The FDA had posted An important note regarding sunscreens:
The FDA is currently proposing big changes to sunscreen regulations, and only physical sunscreens with the active ingredients zinc oxide or titanium dioxide are currently recognized as safe. Americans should continue to use a sunscreen with other sun protection measures as this important rule-making effort moves forward.”
Ingredients of Concern (chemical)
Researches have suggested that a number of chemical UV filters may mimic human hormones. Two of the biggest alleged offenders are octinoxate and oxybenzone.
Oxybenzone: This ingredient is one of the most commonly used sunscreen chemicals. According to the EWG site, Oxybenzone is the worst and the least safe sunscreen filter. It is linked to endocrine disruption, organ system toxicity, and contact allergies.
Octinoxate: This ingredient is a commonly used UV filter that protects from UVB rays, but not UVA sun rays. On the packaging, it may be listed as OMC, methoxy-cinnamate, or Ethylhexyl methoxy-cinnamate. Octinoxate is linked to endocrine disruption by an abundance of data, as well as to reproductive toxicity. (My question is why to use this one at all if he is not protecting from UVA rays??)
Safer Sunscreen Ingredients (mineral)
Titanium Dioxide - a naturally-occurring mineral found in the earth’s crust. Titanium dioxide absorbs UVB rays and some UVA rays, but may not provide full UVA protection.
Zinc Oxide is a naturally-occurring and offers broad-spectrum protection, as it protects against both UVA and UVB rays.
What do dermatologists recommend?
Dermatologists recommend using products with a combination of mineral and chemical filters and with a broad-spectrum SPF 50 and more. People apply about one-third the amount of sunscreen necessary to achieve the SPF listed on the label, that’s why a high number of SPF can compensate somehow the exposure.
Bottom line and my own thoughts about choosing a sunscreen product
Start reading ingredients!
Mineral sunscreens are generally the better and healthier option. We can compare it to a healthy, home-cooked meal, while chemical sunscreens are like the fast-food option of sunscreens.
It is better to use a sunscreen product that combines chemical and mineral filters, rather only chemicals!
If you are using chemical filters sunscreen, make sure to read ingredients and to avoid two of the most harmful filters: Oxybenzone and Octinoxate! (You still can get great protection without using these two filters)
Mineral sunscreens typically take longer to rub into your skin and they also leave behind a white cast, but usually, last longer than chemical formulas. They are not water-resistant, and you should remember to reapply it very often, especially when sweating or on the beach.
Always look for a broad-spectrum sunscreen (these protect you from both types of UV rays: UVA and UVB) with SPF values of 50 or higher, making sure to reapply at least every two hours.
If possible, use the EU brands because their cosmetic regulation is much stricter than in the US and Canada. It would be great to have a UVA Seal on your sunscreen product and PA evaluation.
Have a great and safe summer!
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