Tag: question and answer

I just came across a post where several studies mention that visible light can cause damage too

KindofStephen

…Do you think the damage could have been caused by computer screen light/HEV light? Or is the aging effect of it minimal compared to UV damage?

Great question! The mechanism behind this is believed to be reactive oxygen species (ROS) being created by visible light (400nm to 700nm) and also infrared light (700nm to 1440nm).

Light is a form of energy, the larger the wavelength the less energy it has.

This is why UVA and UVB light, which has a shorter wavelength than visible light, is so harmful. UVC light which has even shorter wavelengths is incredibly damaging, but luckily it is blocked by diatomic oxygen (O2) in our atmosphere.

This paper in the Journal of Investigative Dermatology (Open Access) found less ROS in human skin models when a sunscreen with antioxidants was applied versus the sunscreen without antioxidants.

They also found the produced ROS led to an increase in pro-inflammatory chemicals (cytokines) and MMP-1 in the human skin models. MMP-1 is an enzyme that breaks down collagen in the skin.

Other researchers have proposed additional protection factors for sunscreen, such as Immune Protection Factor (IPF). It’s unlikely we’ll see these labels standardized or used any time soon though.

So, should we freak out and use antioxidants and sunscreen all the time?

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I don’t think there is an answer to that yet. While we’re frequently told by cosmetic companies and anti-ageing gurus that free radicals and ROS are bad and will age/kill us, they also act as important signalers and mediators and have a beneficial function as well.

Recent studies have shown the function of free radicals, ROS, and antioxidants are much more complex than how it’s often portrayed in mass media

One study found that eliminating free radicals caused by exercise could prevent some of the beneficial effects

Another study with mice bred to produce excess free radicals found that they actually had better wound healing

This study found that antioxidant N-acetylcysteine, when applied topically, enhanced melanoma metastasis in mice

Of course there are plenty of other studies that show beneficial effects of antioxidants.

At this point, unfortunately, we just don’t know the long term benefits or effects. It’s becoming more apparent that the amount and context of antioxidants and free radicals is important in creating a beneficial or negative effect.

It’s also important to remember that many antioxidant chemicals have other mechanisms of action that are beneficial that aren’t related to its free radical scavenging ability!

Hope this helps 🙂

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Join in on the discussion!

I’ve shared this post on /r/Asianbeauty and /r/SkincareScience

Hi, previous Anon here. Very nice graphs, and glad to hear you’re switching to something better =)

KindofStephen

…I personally reference Skinacea’s UV filters chart and always pick sunscreens with zinc oxide and/or tinosorb. If the Bioderma is too expensive, there are definitely much cheaper Japanese and European sunscreens with great protection out there! Probably same amount of hassle in terms of shipping though

Thanks for writing back 🙂

Tinosorb S, M and Mexoryl SX, XL seem to have pretty similar protection. Though I haven’t looked at the numbers stringently I would say Tinosorbs tend to offer more absorbance (though I don’t have the concentrations)

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(It’s not really fair to compare Mexoryl XL with Tinosorb S, it would have been better to compare Mexoryl XL with Tinosorb M as the curves are more similar)

I’m going to see if I can find more graphs with labelled axes for different sunscreens and actually graph them all together 🙂

Problem is, the amount used is still limited by Health Canada – not to mention companies choosing to manufacture with these sunscreens have to pay an additional fee. It’s worse in the US as their use is banned.

I’m pretty happy with the Bioderma’s texture, it’s a bit oily on me because of the dimethicone, and makes me shiny by the end of the day, but it’s a small price to pay.

While I do like the texture of Asian sunscreens, I don’t like the PA++++ system, as you can’t tell the difference between say, a UVAPF 20 and a UVAPF 16, as they’d both be the maximum PA++++.

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Hi KindofStephen, I took a look at Ombrelle’s ingredients. It does not have good UVA protection

KindofStephen

Unfortunately Health Canada doesn’t require UVAPF testing, so it’s not clear what the actual UVA protection is.

Ombrelle does contain 3 sunscreens with UVA coverage, but Health Canada has limited how much can be used:

Avobenzone 4%

Drometrizole Trisiloxane (Mexoryl® XL) 2.5%

Terephthalylidene Dicamphor Sulfonic Acid (Mexoryl® SX) 0.5%

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You do raise a good point though, and it’s better to be sure than to assume. I’ll be switching to a European sunscreen, Bioderma Photoderm MAX SPF 50+ with a tested UVAPF of 42.

Having seen the photodamage on my face now, I think the extra hassle, shipping, and price is worth it.

Especially after you consider that UVA (which UVAPF is a protection factor for) is mainly responsible for increased pigmentation, as well as cell and DNA damage.

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