Unlike the cruciferous vegetables, we are not dealing with an activating enzyme leading to the beneficial properties of carrots. So, the raw versus cooked answer falls more in a gray region (but closer to the raw end of the spectrum)- at least when considering falcarinol. There is always more than one aspect to the raw versus cooked argument. Looking at *one* compound is asking for bias, but I am hoping I picked one of the more important compounds to wager my conclusion on. :-) Research from the same leading author as the last three papers, indicates that cooking does reduce the beneficial compounds in carrots, but it doesn’t destroy them.
The following conclusions were reached from this research group:
1) Blanching or boiling carrots leads to a reduction in polyacetylenes by 50%, *but* processed carrots are still a source for these bioactive polyacetylenes.
2) Carrots boiled in water for 12 minutes resulted in a 70% reduction of falcarinol.
3) Both long term frozen storage and steam-blanching 1 cm carrot cubes saw a ~35% reduction in falcarinol.
4) Carrots cooked whole rather than cut up had 25% higher falcarinol levels as well as higher natural sugar levels, making them sweeter tasting.
The anti-cancer benefits observed in the rats correlated to a consumption of 400-600g (fresh weight) carrots a day, so more cooked carrots would have to be eaten to compensate for the reduced falcarinol. Juicing carrots makes this level of consumption very easy. I recall that drinking a lot of fresh carrot juice is one method employed by The Gerson Therapy, which is used to help people recover from cancer. Interesting that the use of carrots for cancer was discovered over 50 years ago; however, the Gerson Therapy is not considered a mainstream cure and is not supported by the current US health care system.
I have my answer, at least in the case of falcarinol. There could be other factors I am not aware of, but I have yet to hear of them. I’ll probably try to find some link to enzymes and carrots since raw foodist are a broken recored with enzymes, but if you don’t hear from me on this it, means I didn’t find anything worth writing about.
My sources: Here is a link to an article that was written by one of the main researchers in these carrots papers. And below that is a link to a paper’s abstract discussing the effects of processing carrots on falcarinol levels (I did not have access to the full paper and didn’t want to pay).