According to the female half of the vapid radio morning show that I listen to (don't ask me why), Jessica Sklar, Jerry Seinfeld's wife, made an appearance on Oprah plugging her book Deceptively Delicious: Simple Secrets to Get Your Kids Eating Good Food. One of the topics of discussion was one of her strategies to get her three children to eat vegetables: apparently, she will mash the vegetables, form them, and fry them. (I should note that I am merely repeating what I heard; the only research I have done is to dig up the title of her book and the spelling of her last name. I have no idea whether what was said on the radio is factual, but it's just a jumping-off point for this post anyway.) I imagine golden brown and delicious nuggets of mashed carrot and the like, kind of like hush puppies. The dynamic duo on the radio were absolutely horrified by this. "That just ruins the nutritional value of the vegetables!" one of them moaned. According to them, Jessica Sklar should be tarred and feathered and branded with a scarlet "B" (for bad parent).
But does frying really destroy the nutritional value of vegetables? I don't think so. There are some people who claim that cooking of any kind is a bad idea with vegetables; and even non-loony people agree that in some cases cooking can degrade the nutrients in them. The folate in spinach is destroyed by heat, for example; and boiling vegetables can eliminate those nutrients that are water soluble. But there's no reason to think that frying is any worse in this regard than any other cooking method and might be better than some: frying is done at a lower heat than some other cooking methods, meaning less heat damage, and it doesn't allow water-soluble nutrients to migrate out of the vegetables. I imagine what really offended these radio guys, though, was that they believe that frying is inherently unhealthy. This is not the case. If the oil is sufficiently hot (325 to 350 degrees Fahrenheit) and the food isn't overcooked, it doesn't become saturated with oil. The oil boils the water in the food, and the water vapor is forced out of the food (that's the bubbling that you see while frying). This outward migration of water vapor prevents the oil from getting in. If the oil isn't hot enough to vaporize the moisture in the food or if cooking continues until after all the water vapor has been forced out, then the food will become greasy and fat-laden. But if it's properly-cooked, this won't happen. So go ahead and cook your carrot puppies proudly, Jessica Sklar.
(See Alton Brown's I'm Just Here For the Food and the fish'n'chips episode of his show Good Eats.)