Dr Mike Hart
http://www.huffingtonpost.ca

Posted: 06/07/2013 8:37 am
 
cancerThe majority of sunscreens on the market today are more harmful than beneficial. Sunscreens are designed to decrease your risk of skin cancer and allow you to enjoy the sun without worry. Unfortunately, most modern day sunscreens may increase your risk of cancer and disrupt the functioning of your hormones.
 
What causes skin cancers?
 
Ultraviolet radiation from UV-A and UV-B rays from sun exposure is the number one cause of skin cancer. Smoking, HPV (the virus that causes genital warts) and artificial light from tanning beds are also associated with an increased risk of skin cancer.
 
UV-A vs. UV-B
 
UV-B rays penetrate only the epidermis (the outer most layer of the skin) and increase your risk of cancer by direct photochemical damage to your DNA, resulting in mutations in your genes. These mutations contribute to wrinkling and aging of the skin by degrading elastin and collagen.
 
UV-A rays penetrate deeper into the dermis (the 2nd major layer of the skin) and can contribute to the development of cancer by increasing reactive oxygen species, which can, in turn, damage your DNA.Therefore, when choosing a sunscreen, you should opt for a sunscreen that blocks both UV-A and UV-B rays.
 
Origin of sunscreen
 
Franz Greiter first invented sunscreen in the 1940s. The active component consisted of zinc oxide. Zinc oxide acts as a physical barrier that sits on the surface of your skin; it offers the same protection as wearing a long sleeve shirt. Zinc oxide has been approved by the FDA and has been shown to be photo-stable against both UV-A and UV-B sun-rays. Because it is not absorbed into the skin, it is nonirritating, non-allergenic, and non-comedogenic (does not cause acne).
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