How Cooking Methods Affect the Nutritional Composition of Vegetables

Me and broccoli, we got a rocky relationships. When broccoli disguises itself in a pot of pasta or roasted and drizzled in butter and garlic, I'm all over it. But when he comes as is or slightly sautéed, I'm not loving the texture or taste. We simply don't jive, and that's okay. 

However, whenever there's any struggle or challenge, I see it as an opportunity to learn something new. I wanted to dive in and learn more about the health benefits of broccoli and find a variation of recipes I could try. That is when I asked myself: Does boiling, sautéing or baking destroy vitamins in vegetables? 

Fruits and vegetables have a variety of vitamins, however, it has been shown that cooking methods alter their nutritional composition. Now you may think eating raw is the best option to preserve the vitamins, but that is not the case. Some nutrients are not absorbed or available in raw foods and even though cooking can degrade some nutrients, it can enhance others. For example, uncooked tomatoes have lower lycopene content than cooked tomatoes. Lycopene is an antioxidant and a carotenoid that may help to prevent heart disease and breast and prostate cancers. 

Here are some additional findings regarding nutrient loss with varied cooking methods:

  • "Boiling, stir-frying/boiling, stir-frying, and microwaving led a great loss of chlorophyll in broccoli. In contrast, steaming did not cause any significant loss of chlorophyll content."1
  • "Vitamin C is water soluble, stir-frying/boiling and boiling might cause great losses of vitamin C by leaching into surrounding water other than thermal degradation." 1
  • "Cooked frozen products have often been shown to be equal or superior to cooked fresh products in their ascorbic acid levels. This is likely due to the losses of vitamin C during storage of the fresh produce." 2

In the end, there's isn't one superior way to prep or cook your food to preserve the nutrients. The key to good health is to incorporate a variety of cooking methods and find ways to enjoy a variety of vegetables throughout the day. 


1 Effects of different cooking methods on health-promoting compounds of broccoli. Gao-feng Yuan,1 Bo Sun, Jing Yuan, and Qiao-mei Wang

2 Nutritional comparison of fresh, frozen and canned fruits and vegetables. Part 1. Vitamins C and B and phenolic compounds. Joy C Rickman, Diane M Barrett and Christine M Bruhn