Sunscreen can be absorbed in the bloodstream, new study says

Sunscreen is one of the best ways to protect against the sun's potentially dangerous ultraviolet rays.

The effects of sunscreen's ingredients on our body is still unknown, but a new study published in the medical journal, JAMA, finds that certain active ingredients can be absorbed into the bloodstream after use.

"Results from our study released today show there is evidence that some sunscreen active ingredients may be absorbed. However, the fact that an ingredient is absorbed through the skin and into the body does not mean the ingredient is unsafe," said Dr. Janet Woodcock, director of the FDA's Center for Drug Evaluation and Research, in a recent press release.

Active ingredients in skin care products are the ingredients that cause physical changes in the skin. In this study, they looked at six main active ingredients that were used in different combinations in sunscreens: avobenzone, oxybenzone, octocrylene, homosalate, octisalate and octinoxate.

There are two main types of sunscreen sold to consumers.

Mineral sunscreens sit on top of the skin and reflect the rays away but leave a white residue on the skin and can wash off with sweat and water.

Chemical sunscreen goes on easier and absorb into your skin. These chemical sunscreens are the ones that have now been confirmed to enter your blood stream, but it is still unknown if this is cause for concern. Woodcock says, "This finding calls for further industry testing to determine the safety and effect of systemic exposure of sunscreen ingredients, especially with chronic use."

This was a follow-up study to one done last year. Larger in size and testing additional sunscreen active ingredients and formulations, researchers asked people to apply sunscreen four times a day. Over almost a month researchers tested blood samples and confirmed that all six active ingredients in sunscreen are absorbed in the bloodstream at measurable levels.

So, should you stop using sunscreen?

Dermatologist Dr. Michele Green from Lenox Hill Hospital NYC, says no. "Until we know further, it is important to continue to use sunscreen since it is a good way to protect skin from the sun's UV rays and a lot of these agreements have been around for a very long time," said Green.

Green agrees that further studies need to be done in order to determine if these substances are actually toxic and how absorption differs in infants, children, and cancer patients with weakened immune systems. "We don't yet know the significance of these ingredients in the blood stream," said Green.

According to the World Cancer Research Fund, "melanoma of the skin is the 19th most commonly occurring cancer in men and women."

"Given the recognized public health benefits of sunscreen use, FDA urges Americans to use sunscreens in conjunction with other sun protective measures (such as protective clothing)," said Woodcock.

Green went on to recommend, "limiting time in the sun between 11:00 a.m. and 2:00 p.m. when the sun's rays are most intense; wearing protective clothing that covers skin that is exposed to the sun, such as long-sleeved shirts and pants and a hat with a wide brim."

Dr. Manavjeet Sidhu, MD, MBA, is a resident physician in emergency medicine and contributor to the ABC News Medical Unit.