这篇说:生的比熟的有效。
Possible mechanisms by which cooking affects the relationship between vegetables and cancer risk include changes in availability of some nutrients, destruction of digestive enzymes, and alteration of the structure and digestibility of food. Both raw and cooked vegetable consumption are inversely related to epithelial cancers, particularly those of the upper gastrointestinal tract, and possibly breast cancer; however, these relationships may be stronger for raw vegetables than cooked vegetables.
from http://cebp.aacrjournals.org/content/13/9/1422
这篇讲 Consuming the proper kinds of foods and changing the method of food processing were beneficial to increase the intake of lutein, zeaxanthin and β-carotene.
https://www.ncbi.nlm.nih.gov/pubmed/21418822
这篇说到煮或蒸的胡萝卜含有更高的胡萝卜素
Cooked carrots, spinach, mushrooms, asparagus, cabbage, peppers and many other vegetables also supply more antioxidants, such as carotenoids and ferulic acid, to the body than they do when raw
https://www.scientificamerican.com/article/raw-veggies-are-healthier/
下面这篇详细的比较了胡萝卜不同烹法造成不同成分流失,而展示不同的效果。认为熟的比生的有效,其有效成分可能是falcarinol 。
There are several steps in the chain of logic that implies “whole carrots fight cancer”, and although the concentration of the chemical falcarinol may be maintained in carrots cooked whole, it is yet to be proven that falcarinol can actually prevent cancer in humans. The researchers quote an animal study that was conducted four years ago, which showed that rats fed on a diet containing carrots or isolated falcarinol were a third less likely to develop tumours than those in a control group.
From https://www.nhs.uk/news/cancer/cooking-carrots-and-cancer/
另一篇支持Falcarinol 的研究报道 https://www.sciencedaily.com/releases/2005/02/050212184702.htm