Most of us know that signs of inflammation can be a good thing. It means that your body is responding to "an attack" and using the best frontline defense it has against infection or disease. Inflammation is very often the sign that we need to seek medical attention because if the inflammation progresses, it can signal that the disease or infection is progressing and overwehlming the body's defenses. What about chronic inflammation? Is that worrisome?
According to recent research it is of concern and it may be linked to or help to actually nurture a risk for skin cancer. In theory, experts thought that inflammation should prevent tumors. In fact, it may actually put you at risk for skin cancer. IDO is an enzyme that acts kind of like a firefighter, to make sure inflammation remains under control. Unfortunately, it may also be recruited to help to protect early malignant cells.
Experts exposed mice to a single dose of a carcinogen and then actually painted a small portion of mice skin with poison ivy twice a week for 20 weeks in order to instigate inflammation (and mimic chronic sun exposure). IDO was naturally activated by this process and it created an environment that nurtured pre-cancerous cells, allowing them to grow into tumors. The researchers repeated the study but this time they de-activated IDO and the result was that tumor devlopment dropped off dramatically.
The author of the study felt that this scenario is exactly what can occur with chronic sun exposure and its resulting inflammatory response - namely, the sunburn - which means that more than one process is going on when sun exposure raises the risk of skin malignancies. Sure the UV light exposure itself can cause cancerous changes in the skin, but, now a new process has been revealed - the fact that the sunburn itself stimulated IDO and its "cancer protection" powers are unleashed.
So the key is the "chronic exposure/chronic sunburn." One of the authors of the study feels that it is like you are "lighting a fire" and indeed inflammation comes from the latin word inflamatio, which means "to set a fire." IDO favors the tumor growth so anything that stimulates this enzyme (including immune supression treatments as are used in transplant patients) can increase the risk for certain kinds of cancer tumors. Researchers are now looking to use the IDO supressor or inhibitor in breast cancer patients getting chemotherapy.
Another good reason to use sunblock everyday, year round, on yourself and your kids.