"Most people prefer to rub the cream into the skin," said Lead researcher Dr. Rachel Haywood. "They find it more pleasant and comfortable. However, our research shows for the first time that if the cream is rubbed in, the protection is minimal."
In their study of skin cancer -- which kills more than 2,000 people annually in the UK, according to the journal PhotoChemistry and Photobiology -- the researchers recreated intense sun conditions in their lab and exposed skin leftover from plastic surgery operations.
The study found that allowing sunscreen to dry into a white film on the skin offered much better protection than rubbing it into the skin. Rubbing the substance into the skin reduces its UV protection levels to near-zero because it sinks into sweat glands and skin lines, causing uneven protection.
Rubbing sunscreen in does still protect from the UVB rays that cause skin to redden, but without this conspicuous indicator of skin damage, people may stay out in the sun longer, the scientists reported.
The chemicals in commercial sunscreen products have been found to be toxic in some studies, and may actually promote some forms of cancer. According to natural health advocate Mike Adams, sensible sun exposure is imperative to the body's production of vitamin D, a chemical that has been shown to reduce the risk of many types of cancer. Adams adds that following healthy nutritional habits and eating antioxidants from sources like astaxanthin and blueberries boosts the skin's natural sunscreen ability.
Adams also warns that many sunscreen products contain cancer-causing chemicals, including carcinogenic fragrance chemicals. In this way, Adams explains, using sunscreen may actually increase the risk of liver cancer.
For more information on sunscreen and the hazards of personal care products, read "The Hundred-Year Lie: How Food and Medicine Are Destroying Your Health" by Randall Fitzgerald, available for purchase here.