Fresh vs. Processed: Cooking is processing too!

Cooking really is processing your food. Even the minimal processing of cooking your food can lead to nutrient loss. However the difference in nutrient loss between processed foods purchased at a grocery store and raw foods cooked at home can be significant. Processed foods typically have a nutrient loss of 50% to 80%. Whereas steaming or blanching cause 5% to 15% nutrient loss. Of course this all depends on the nutrient and how carefully you watch the vegetables to make sure you do not overcook. Oftentimes this minimal nutrient loss is beneficial as the cooking process aides in digestion and absorption of the vitamins and minerals into your body. In fact, some foods contain enzyme inhibitors which prevent nutrient digestion if uncooked.


This list, adapted from Dummies.com, shows which nutrients are sensitive to which kinds of processing:

Vitamin A - Heat and Fat
Vitamin D - Fat
Vitamin E - Heat, Air, and Fat
Vitamin C - Heat, Air, and Water
Thiamin - Heat and Water
Riboflavin - Water
Vitamin B6 - Heat, Air, and Water
Folate - Heat and Air
Vitamin B12 - Heat and Water
Biotin - Water
Pantothenic acid - Heat
Potassium – Water

For example then, sautéing carrots which are high in Vitamin A in olive oil would be a poor choice for nutrient retention. But don’t get too wrapped up in memorizing this list or confusing yourself with cooking times and temperatures and methods. Simply avoid overcooking your food and enjoy raw fruits and vegetables whenever possible.