Misleading and False information might be what the public has been fed over the years regarding sunscreens and skin cancer, especially malignant melanomas. Beginning with my heading above. There is no such thing as “Melanoma“. It is either a MALIGNANT melanoma or a BENIGN melanoma, the two have NOTHING in common. They don’t even have to be pigmented.
The general population is being confused by the pseudo scientific information presented to them by the companies marketing the various types of skin protection, from sunscreen creams to clothing, hats, motor vehicle window tints, etc.
There are now more people using sunscreen on a regular basis than ever before and in spite of that, the percentage of superficial skin cancers as well as malignant melanomas has been increasing. So, can it be possible that the sunscreen that you are using might place you at risk of developing cancer, rather than preventing it ?
The SPF factor displays the percentage of presumed protection against UVB (which is the “good” UV) and offers no protection against the “bad” UVA. There are some “broad spectrum” sunscreens on the market that protect against UVA as well as UVB, but, the percentage of protection against UVA is not stated. SPF only applies to UVB. There are also two kinds of sunscreens. One is the oily type on the skin surface and the other the “dry” type that absorbs into the skin. A new type of sunscreen has also been developed in Australia that claims that it blocks only UVA and allows the UVB to come through, so that vitamin D can be produced and not be blocked. It would then also allow the natural melanin in the skin to increase in a normal way, due to the stimulation by the UVB. The idea is good.
When you “tan” the superficial UVB naturally increases the melanin in your skin, which then in turn becomes darker and then offers a natural barrier against the “bad” UVA, which has a longer wave length and penetrates deeper. It seems that chronic low grade exposure to the sun increases the natural production of melanin in the skin which in turn protects the skin against the harmful UVA in a completely natural way.
What is more important than the type of sunscreen, is your type of skin. Certain types skin should never be exposed to sun. See the Fitzpatrick scale.
There is evidence that UV can increase the incidence of some superficial skin cancers. But they are generally more localized and do not metastasize. There is NO evidence that sunlight can or does increase the incidence of malignant melanoma. Furthermore there is also a difference between benign and malignant melanomas. It is NOT the natural course for benign melanomas to change into malignant melanomas. Furthermore, malignant melanomas, basal cell carcinomas and squamous cell carcinomas have NOTHING in common. The one cannot progress to the other. They are as different from each another as chalk and cheese.
The production of Vitamin D is also prevented by sunblock. Vitamin D is essential for our bone strength as well as preventing various kinds of systemic cancer such as breast, colon and others. Not only systemic, but, also in the skin. The natural production of Vitamin D by the skin also cannot be replaced by drinking supplements. It is possible that sunblock can cause vitamin D deficiency in a person.
There was an interesting article by Margaret B. Planta, in the recent JABFM of Nov / Dec 2016, regarding whether our message of sunscreen protection and melanomas is correct. Sunscreen and Melanoma: Is Our Prevention Message Correct?
Once again, a good example where we should probably not interfere with the natural functionality of our bodies. We were designed as pretty efficient functioning creatures.