Not All Vegetables Lose Their Nutritional Value When Cooked. Some Actually Become Healthier.
With all the food trends out there today, it's hard to know what's truly good for you. When it comes to veggies, there are many ways to prepare our favorites. But whether we eat our greens raw or cooked isn't just a choice for our taste buds, it's also a choice for our health.
Have you ever wondered why we don't eat raw potatoes? Or why vegetables change color when they're cooked? There are many questions about whether cooking vegetables will add to or reduce nutritional values. South Florida chemist Dr. Barbara Colonna lays the pros and cons out on the table for us.
1. What happens
As a reminder to those of us who are far removed from chemistry class, there are two types of reactions—physical and chemical. Physical reactions tend to occur at lower temperatures, whereas chemical reactions need an energy source to occur, such as heat. Heat provides enough energy to cause molecular compositions to change, breaking down cell walls and changing the textures and colors of your vegetables.
2. What you'll lose
When veggies are cooked, many lose micronutrients, like vitamin C, folate and riboflavin. This is because they are soluble in water, so methods such as boiling extract the nutrients. But, do you really want to eat that raw spinach?
3. What you'll gain
While some vegetables lose nutritional value, some actually become healthier when they're cooked. For example, The Journal of Agricultural and Food Chemistry found that cooking tomatoes at about 200 F for 30 minutes increases the amount of accessible lycopene content. Lycopene is a cancer-fighting nutrient already found in tomatoes. So while the amount of lycopene doesn't increase, it does transform into a compound that's easier for the body to use and break down.
4. What to consider
If you're still pondering why we don't eat raw potatoes, here is your answer: Raw potatoes are even harder to bite into than apples, and they're full of starch. But, according to On Food and Cooking: The Science and Lore of the Kitchen, when starchy vegetables are exposed to high temperatures, the proteins begin to change and the rigid cells swell with water, producing a chain of sponge-like cells that hold water pockets. Visualize this by thinking of squeezing a raw potato versus a cooked potato.
So, whether you're eating your vegetables raw or cooked, remember to make them a part of your daily diet—your body will thank you.