Saturday, February 2, 2013

Nutrifact 5: To cook or not to cook: Vegetables

I've returned...and this time as an RD. I passed!! I completed my bachelor's degree and internship and passed the exam...which are the qualifications for becoming a Registered Dietitian...but I'm not done yet! I'm currently working on my master's and plan to graduate in December.

Because of my frenzied studying the past few months before I took the exam, our dinners have mostly been taking advantage of the frozen section of the new Trader Joe's in town. However, I am now on here to write a blog post that has been insanely long in coming.

Have you ever wondered if those green beans are still as nutritiously wonderful after they're been simmering for half an hour? Should I be eating those carrot sticks raw? I'm here to share what I've learned about this topic so you can squeeze the most out of your vegetables!

Vegetables contain many wonderful minerals, water-soluble vitamins, antioxidants, and phytochemicals. However, these can be lost if they are cooked certain ways, such as in water or for long amounts of time. I read a few research articles to try to understand this issue. As an RD, it is very important to me that what I say is evidence-based.

In 2008, a study was performed to determine what happens to carrots, zucchini, and broccoli when they are boiled, steamed, or fried. Interestingly, the antioxidant capacity of the vegetables increased after all three cooking methods. This is likely due to the softening of the vegetable's structure, allowing the antioxidants to be more readily released in our digestive tracts. However, boiling and steaming better preserved the antioxidants than frying. Also, all three methods reduced the amount of vitamin C in the vegetables. This is to be expected, however, because vitamin C is very sensitive to cooking.

In contrast, a 2012 study on the effects of cooking on kale discovered that this vegetable in the cabbage family loses most of its antioxidant activity after cooking (vitamin C, polyphenols, and beta-carotene in this case). They concluded that vegetables in this family may be best eaten raw or with little processing.

So now it was starting to get confusing...which vegetables should I cook and which should I not?

After a little more digging I found that, in general, the nutrient availability of vegetables increases after they are cooked for a short amount of time and with little or no water.

Now, I know there are some people who would want to have a chart on their refrigerator that says exactly which vegetables to eat raw and which to cook and how to cook them the best way. However, in my mind this is complicating things way too much.

My goal is to make eating healthy a simple matter. 

In my opinion, the best way to eat your vegetables is to eat them. Too many people shy away from vegetables to tell them that the only way they should eat kale is raw.

Have fun with your vegetables! Buy different ones every time. Slice them up and try them raw. Saute them in a little olive oil and salt and pepper. Roast them with some grated cheese. Pop them in the microwave with a teensy bit of water. The point is to eat them and to eat a variety.

The Academy of Nutrition and Dietetics suggests the following tips for cooking vegetables:

-Clean your thick-skinned vegetables under running water instead of soaking them.
-Steam instead of boiling vegetables. Cooking vegetables in water causes their nutrients to leach into the water, which is then discarded.
-If you do prefer to cook vegetables in water, freeze the water for later use in soups and sauces and such.
-Microwave. This may sound strange at first, but microwaving your vegetables actually allows for a very short cooking time, which maximizes nutrient retention.

I agree with these suggestions. To make it even more simple...don't submerge and don't overcook. If you can remember these two pointers, you'll be golden!

So get out there and try some new veggies!

1 comment: