Research shows that cooking vegetables can increase some nutrients, but not all methods are the same. Choosing the healthiest ways to cook your vegetables will help you boost nutrition and improve health.
Microwaving not only provides a quick cooking option, it may also help foods retain more nutrients. Studies show that steaming vegetables in the microwave may be the best way to preserve most vitamins and minerals, especially vitamin C which rapidly decreases with other cooking methods.
Steaming vegetables in a metal or bamboo steaming basket is another ideal option. One study showed that steaming helped to retain the cancer-fighting glucosinolates found in broccoli. It also retained the carotenoids in zucchini and significantly increased carotenoids in carrots and broccoli. Additionally, it was found to best protect the polyphenols (a group of antioxidants) in these vegetables when compared to boiling and frying.
In one study, sauteing (stir-frying in a small amount of oil) helped to retain nutrients (especially vitamin C) when compared to boiling and stir-frying without oil. While sauteing uses high heat, food is cooked quickly which helps reduce nutrient loss. A small amount of oil also adds flavor to the food, unlike steamed vegetables which are bland when unseasoned.
Boiling is often considered a poor method for healthy cooking because nutrients are pulled from the food and into the cooking water. But boiling may not be as bad as we thought. Studies show that boiling produced results similar to steaming for preserving carotenoids in zucchini, and increasing them in broccoli and carrots. It retains vitamin C content better than frying, but not as well as steaming and sauteing.
Roasting vegetables exposes them to high heat for longer periods of time which can decrease vitamins, but not all nutrients are lost. The benefit of roasting is that it brings out the best flavors in vegetables making them much more delicious without adding unhealthy fat and sodium. If you find steamed vegetables bland, a few roasted vegetables mixed in can improve the flavor while still providing plenty of nutrients.
Studies support that frying is the worst cooking method for preserving the nutrients in vegetables. High temperatures quickly degrade even the most stable vitamins. Vitamin C, carotenoids and polyphenols all decrease in foods cooked by frying. Fried foods can also contain saturated fats, trans fats, and excess sodium making frying the least desirable cooking method for health.