Normal cancer cell division from NIH

Image via Wikipedia

Cancers can be caused by two related phenomena: A) Genes that cause cancer called oncogenes and B) genes that prevent cancer called tumor suppressor genes. Obviously if we have our oncogenes turned off and our tumor suppressor genes turned on we are in great shape (at least as cancer goes). If on the other hand we have our oncogenes on and our tumor suppressors off, we might be in real bad shape. Genes tell our bodies what to do and rebuild new cells so that we can continue to live a normal life. Our bodies have a system outside of our genes that was designed to keep our bodies running well. This system looks to turn off failing genes and activate genes needed to fight diseases. This management system is called epigenetics. We obviously need food, water, and nutrients to live. These things come from our food source. If we constantly eat bad foods we will knock the management system off-key just like putting bad fuel in our cars will eventually destroy the engine.