I’ve done a little reading about this topic, and you can find pretty strong opinions, especially on the side of raw food. The question I’m addressing here is not which is more appealing, but which is healthier. I think that question can be looked at from two aspects: which is the most digestible and which contains the most nutrients. Here’s what I have learned about digestibility and nutrition.
1. Digestibility. Raw vegetables contain enzymes that aid digestion. Cooking can destroy those enzymes and hinder digestion. However, vegetables also contain cellulose, a fiber which we have difficulty digesting, even with those enzymes. While fiber doesn’t contain nutrients, it is an important part of digestive health. Cellulase, the enzyme needed to digest cellulose, is produced by intestinal bacteria. Cooking vegetables, even lightly steaming them, breaks down that cellulose layer and makes them digestible. Blending or pureeing vegetables, such as in a smoothie, also helps make them more digestible.
2. Nutrition. Generally, minerals withstand heat, especially dry heat. Vitamins are more easily destroyed, but do better with moist heat. Both vitamins and minerals leach into cooking liquid, and it is good to use that liquid in the meal. Some nutrients, particularly vitamin C, are easily destroyed by heat. On the other hand, some nutrients are made more available by cooking. In one study, lycopene in tomatoes rose 35 percent after cooking them.
In addition, fresh fruits and vegetables sold in stores have often lost many of their nutrients by the time we eat them. It is best to chose items that are in season and grown locally. Frozen vegetables are usually frozen at their peak and could contain more nutrients than fresh. Obviously, they would have to be cooked.
The bottom line for me is that we should eat a variety of vegetables in a variety of ways. The important thing is to eat them. If you won’t eat broccoli raw, but you will eat it cooked, then cook it and eat it. If your child eats carrots raw, but not cooked, then give him raw carrots. You get what I’m saying: Eat Your Vegetables! (And I’m speaking to myself as well.)
You can find more information at the following sites (and many more with a little searching).
Surprising News About How Cooking Affects Antioxidants – NutritionData
Vegetable Nutrient Chart – Dr. Decuypere
Fact or Fiction: Raw veggies are healthier than cooked ones – Scientific American
How to Eat Your Vegetables Raw – Body Ecology
This post is third in a series on vegetables. I’ll finish next week with ways to cook vegetables. You can view the first two posts here:
What do you think about cooked versus raw?