if our skin cells are constantly dying and being replaced by new ones, how can a bad sunburn turn into cancer YEARS down the line?
In: 3306
The truly dangerous changes don’t happen at the epidermis level. The concerning damage occurs in the dermis to melanocytes. A group or cluster of melanocytes is called a mole (or a nevus) and a mole is evidence something has happened. That something is when melanocytes are “zapped” by UV *radiation*, this activates them by way of tyrosinase enzyme. Activated melanocytes create melanin, which darkens your skin aka a tan. A tan is itself evidence that your dermis has been exposed to UV. Not surprising, right? Sit in the sun, get a tan. But the mechanism is this enzyme causing melanocytes to create melanin.
The exposure to UV *radiation* causes alterations in the DNA of the melanocytes, which is why repeated exposures and/or too intense of exposure can cause this DNA damage to become carcinogenic.
I’m italicizing radiation because many people don’t seem to understand that UV is high energy wavelengths being emitted from our star, just like gamma and x-ray, and just like those wavelengths of radiation UV will alter your DNA (why you wear a protective lead shield when getting x-rays performed). This is why the recommended amount of tanning bed use is exactly 0.
Also, UV-A and UV-B pass through the ozone layer. This is why you should only buy broad spectrum sunblock, which I think is standard now.
Latest Answers