We all know the powerful benefits of regular vegetable consumption. Vegetables of all types are packed with vitamins and minerals, cancer fighting phytonutrients and a good amount of essential dietary fiber. And they are a great way to fill you up without packing on the calories – i.e. great fat loss tool. You may have also heard that certain cooking methods affect the ‘active’ content of nutrients in vegetables. I have been asked before, “You’re a trainer and you cook your vegetables?” What…. Are you kidding me? Cruising the aisles of Whole Foods I have even heard some hardcore raw foods advocates say that cooking vegetables is the equivalent of murder,... “you take the life out of them”. Seriously?, Am I a bad person for torturing vegetables in our Stir Fry pan? But I digress. Me personally, I can handle a good salad with raw vegetables (thanks to the fatty dressing), but you will not find me snacking on good, old raw vegetables like it was a handful of my favorite salted nuts. I definitely like to cook my vegetables, especially stir frying them. So what is the effect of cooking on vegetables and is one cooking method better than others?
There have been many studies on the effect from cooking vegetables. And although there is some reduction in nutrients, especially from boiling and crock potting, the good news is you are not ‘killing’ the value of these foods.
Boiling vegetables or making your favorite soup loaded with vegetables can cause about an average 30-50% reduction in nutrients. For example, boiling broccoli has a 38% reduction in Vitamin C. The longer you boil or ‘crock pot’ the vegetable the higher the percentage loss. And the more you reheat these vegetables the more the percentage loss. I suppose if you make a good vegetable soup and let it sit for hours on the stove top (I wonder if my wife is reading this… she makes a ‘mean’ soup) you could potentially kill all the nutrients in the vegetables. I think the bottom line is to try and not boil your vegetables, and if you are going to make a soup try to consume it near its completion and not allow it to sit for hours.
Steaming and quick stir frying with a moderate amount of oil were shown to be the best choices. Steaming retains about 90 to 100% of the nutrients. Stir frying retains about 80 to 95% of the nutrients. Baking retains about 60 to 75% of the nutrients. Sautéing, which typically uses more oil than stir frying, retains about 60 to 75% of nutrients.
So yes there is some reduction in nutrients when cooking vegetables. But I look at all this cooking stuff in a different way, kind of the same way that I have always looked at everything related to good health and wellness choices. Consistency is king… Not perfection! If cooking your vegetables makes you enjoy them that much more and if cooking allows you to make them part of your diet more often - then do it. If adding a little bit of oil and spices and stir frying works better for you – then go for it. Yes, you might not want to consider the vegetables in a soup the best way to get them, but that doesn’t mean it is a horrible food choice.So go ahead, torture those little guys. You are going to eat them anyways!