Researchers have identified a natural pesticide in carrots which they believe stimulates mechanisms in the body that fight cancer:

A compound in carrots may reduce the risk of developing cancer, research suggests.

A team from the University of Newcastle Upon Tyne found the natural pesticide falcarinol reduced the risk of cancer developing in rats by a third.

They hope the discovery will lead to a new generation of anti-cancer drugs - and tips to growers on how to boost the beneficial properties of their produce.

I prefer my carrots cooked, but this experiment used raw carrots. It is not known if cooked carrots or carrot juice will have the same effect.

Oh, and as with everything, balance is critical. The article does note that falcarinol is toxic in large amounts. If you eat 400 kg (nearly 882 lbs) of carrots at once, you would die. (Good to know!)