It is common knowledge that vegetables are healthy, and that most people do not consume enough in their diet. For those people who do eat vegetables on a regular basis, there is often confusion as to the healthiest method of cooking. Some experts recommend eating everything raw, while other studies show that cooking may increase the antioxidant power of certain vegetables.
A study in the Journal of Agriculture and Food Chemistry compared the effect of different cooking methods, such as frying, boiling, and steaming, on the phytochemical properties of three different vegetables. They found that cooking definitely alters the nutritional composition of vegetables, but sometimes that change is beneficial. For example, the lycopene content is greater in cooked tomatoes than raw ones. However, they did find that frying retained the fewest amounts of antioxidants, and that steaming and boiling retained more antioxidants overall.
There is no one “best” way to eat vegetables; in fact, each vegetable is unique. No single cooking preparation is superior to another for preserving 100% of the nutrients while cooking. Cooking can degrade some nutrients while enhancing other nutrients, and therefore, it is a tradeoff when deciding how to prepare them. Consumers should vary the way they eat their vegetables to get the best benefits from their food.