A recent study from Pennsylvania State University suggests that sunscreen may not only protect from sunburn and skin cancer but also can help maintain the health of the blood vessels.
For the study, the researchers recruited 13 healthy participants all of whom had light-to-medium skin tone. One arm of each participant was exposed to UVR, and the other arm served for the control purpose. The UVR exposure equaled to approximately one hour of staying outside on a sunny day.
The analysis showed that in the areas, exposed to UVR, nitric oxide (NO) was prevented from triggering the relaxation of the muscles in blood vessels reducing the ability of the body to cool itself down. At the same time, areas with the sunscreen didn’t show any reduction of NO-associated vasodilation.
A clinical review, published in The Journal of the American Osteopathic Association, finds that about 1 billion people around the globe may experience vitamin D deficiency or be insufficient of vitamin D levels because of chronic disease and improper sun exposure connected to sunscreen use.
Moreover, the study found that 95% of African American adults may be vitamin D deficient or have insufficient levels of the vitamin.
A researcher on this study Kim Pfotenhauer, DO, assistant professor at Touro University, explains: “People are spending less time outside and, when they do go out, they’re typically wearing sunscreen, which essentially nullifies the body’s ability to produce vitamin D. While we want people to protect themselves against skin cancer, there are healthy, moderate levels of unprotected sun exposure that can be very helpful in boosting vitamin D.”
A new study by Danish scientists has shown that the chemical substances that protect the skin from harmful UV rays, may be the reason for male infertility.
Sunscreen can deprive a man of having children, destroying sperm cells. The fact is that almost half of the substances present in the composition of these funds mimic the action of the female hormone progesterone, which prevents the normal functioning of male germ cells. Lotion absorbed by the skin, whereupon the chemicals get into the bloodstream.
Niels Skakkebaek, a professor of the University of Copenhagen, said that these results are interesting and may partly explain why unexplained infertility is so common. Professor and his colleagues tested 29 UV filters permitted for use in the manufacture of sunscreens and lotions, for live sperm cells obtained from completely healthy donors. Nearly half of the UV filters have broken function of sperm cells.
Sperm has a special channel, which is a receptor for the female hormone progesterone. 13 filters of all tested violated the vital function of male sex cells – such as the movement of sperm.
Professor Skakkebaek said that this effect began at very low doses of chemicals, lower than levels of certain UV filters found in people after applying sunscreen all over the body.
This proves once again that the principle of “the more – the better” does not work when it comes to health. And when choosing a sunscreen is better to be safe and thoroughly examine its composition.