Thursday, December 6th, 2018
We all think we know about the sun, what it does to us and how to protect ourselves from it. Unfortunately, most of us really do not know what we need to know. A great deal of this is because most of the people who write about this keep repeating information that has been outdated for years. Though you may think that this is implausible, several studies have shown that it takes an average of 13 years before a new discovery is adopted into general usage. Unfortunately, it has already been well over 20 years we learned new information about the sun and how to protect from it, and it has still not been generally accepted.
This is based on what we previously knew about UVB. Since UVB is immediately absorbed rather than being reflected, it is much less strong in the shade or inside. It is also what causes sunburn. Because of that, it was considered really bad. Also, many modern windows block UVB so you would not sunburn inside. None really block UVA, which is present almost equally all day, all year, at all latitudes and even inside and in the shade. UVA is also the “bad guy.” It is what really causes sun damage. We remember the effects by “UVB, Burn, UVA, Aging.” We, therefore, need to protect from UVA all the time every day. This requires the proper sunblock and sun protective clothing.
This is similar to the above. While UVB is twice as strong in the summer as it is in winter, the strength of UVA is almost the same. This means that you need to protect from UVA aging all year. This is also true indoors and on cloudy days as UVA is unchanged in strength then also.
SPF is a designation designed to tell you how well the sunscreen protects from sunburn. It has no bearing on whether it protects you from sun damage, however. As I said, sunburn is caused by UVB that is absorbed by everything, including your skin. This is the reason it causes a burn (all the energy is concentrated in the outer skin layer) and present twice as much in the summer as the winter, at noon as morning and evening and in Florida as in North Dakota (because of atmospheric absorption). Since it is UVA that is absorbed into all layers of the skin and causes cellular damage resulting in skin cancers and aging, you need a way to tell if what you are using does that. SPF does not do this.
Since December of 2013, any product labeled as a sunscreen or sunblock have to protect from both UVA and UVB. Any product that simply puts an SPF on the label but does not claim to be a sunscreen or sunblock does not necessarily have any UVA protection and any that it does have is usually short lived. Even those that are approved as sunscreens are not all equal in the protection provided. There is a long list of chemical sunscreens and the manufacturer can use a mixture of them. Some are better than others. The one thing they all share is that they only last about an hour if you are outside or 2 hours if you are inside. The physical sunblocks are zinc and titanium oxide. Both protect from both UVA and UVB and last until washed or rubbed off. However, zinc is by far the best, protecting maximally over a larger spectrum.
There have been many claims over the years. Most recently, several companies have marketed either a pill or something to drink that is supposed to protect you from sun damage. None of these products work, and the FDA has recently warned these companies to stop making such claims.
Since zinc oxide provides the widest spectrum of maximum protection and lasts as long as it remains in place, this is, not only the best, but the most practical. Probably the main reason it has not been adopted better is another myth, “it is that white stuff the lifeguards used to wear on their noses.” A recent health writer even bemoaned that we did not have a reasonable sunblock or “something other than that white stuff.” The fact is that it has not been “white” for well over 20 years and rubs in clear but provides superb protection. Instead of looking for SPF, we recommend that you simply look at the ingredients and buy one with at least 8% zinc oxide. This will give you all the UVA and UVB protection you need. We also suggest that your clothing is sun protective, either bought that way or washed with Rit SunGuard that washes in sun protection for 20 washes. We sell both in the office. Call, come in or visit our web site to find out more.