Q: Are cooked carrots more nutritious than raw?
A: Yes, cooked carrots are more nutritious, but you still get plenty of nutrients from raw carrots.
Cooking, especially prolonged boiling, does reduce the vitamin content of vegetables. But carotenoids, such as the beta carotene in carrots, are more readily available when vegetables are cooked or processed (such as chopped or puréed). Cooking and processing help release the carotenoids, which are bound to the cell wall “matrix” of the vegetables.
The same is true of tomatoes. For example, studies have found that people consuming an ounce or two of tomato paste end up with more than twice as much lycopene (another carotenoid) in their blood as when they ate larger amounts of fresh tomatoes. Ounce for ounce, processed tomato products such as sauce, paste, or juice contain two to 10 times as much available lycopene as fresh tomatoes.
However, for most vegetables, especially those rich in vitamin C, it’s best to keep heating to a minimum. Steam them quickly or microwave them to preserve the most vitamins.
Bottom line: In the end, it doesn't matter much—raw or cooked, you can’t go wrong with veggies.
Also see 60+ Healthy Ways to Cook Vegetables.