When Bugs Bunny uttered his famous catchphrase, "What's up, doc," he was often chomping on a carrot, though he wasn't inquiring about the health benefits of the vegetable. New findings suggest that they would have had a lot to talk about: results from a recent rat study indicate that a naturally occurring compound in carrots reduces the risk of developing cancer by a third.

The compound falcarinol helps protect carrots from fungal diseases. Kirsten Brandt of the University of Newcastle upon Tyne in England and her colleagues investigated the effects of the natural pesticide on rats suffering from precancerous tumors. The researchers studied 24 animals that were divided into three groups: one group ate regular feed that did not contain falcarinol, another group consumed the feed plus carrots and the last group dined on the feed with falcarinol added to it. According to a report published in the February issue of the Journal of Agricultural and Food Chemistry, after 18 weeks the rats that received falcarinol (either from carrots or feed additives), were one third less likely to develop full-scale cancerous tumors than were rats in the control group.

Falcarinol can be toxic in large amounts, but it would take 400 kilograms of carrots to reach a lethal dose. The scientists used raw carrots for the study, so it is not yet known if cooked carrots or carrot juice will exhibit the same beneficial effect, and the mechanism for the vegetable's apparent cancer-fighting effects remains unclear. "We now need to take it a step further by finding out how much falcarinol is needed to prevent the development of cancer," says Brandt, "and if certain types of carrots are better than others, as there are many varieties in existence, of different shapes, colors and sizes."