Dear PWN,

What impact does microwaving food have on its nutritional content? I have heard that microwaving devoids food of its nutrients, more so than heating on a stove. I am hoping that is false.

-John from University City, MO

The microwave question. We’ve all asked it at one point or another, and maybe we’ve even opted out of researching it in fear of what we’d find.

I actually do not own a microwave. We had a little one that had Ed inherited before we even met, and it was such an eyesore on our counter, and so rarely used, that we decided to get rid of it. I can honestly say that I don’t even miss having one around. If I ever designed a new kitchen maybe I’d designate a place for a microwave, but for now we don’t really need one.

However, I am still very interested in the topic of what different cooking methods do to nutrients in food. I did a little research, and here is what I found:

The main methods used for cooking vegetables are boiling, steaming, microwaving, or stir-frying. All types of cooking alter the food in some way. Generally speaking, the more heat used, the more nutrients and enzymes are destroyed.

Any time vegetables are cooked in water, greater nutrient loss occurs. The water leeches nutrients and, unless the water is used in the final dish, these nutrients are lost. Water-soluble vitamins include vitamins B and C, which are abundant in fresh vegetables. These are the most heat sensitive vitamins, and therefore are easily destroyed.

A study published in The Journal of the Science of Food and Agriculture (2003) found that when vegetables were microwaved in water, they lost 74% - 97% of their antioxidants. A 2009 study came up with similar results: broccoli that was boiled or microwaved retained fewer nutrients than broccoli cooked without as much water, such as by steaming or stir-frying. Other studies I found, however, were inconclusive as to whether or not microwaving foods was more nutrient-destructive than other cooking methods.

Despite the conflicting information on this subject, one thing is certain: microwaving does deactivate enzymes, which are useful when it comes time to digest the food. Other cooking methods can also deactivate at least some enzymes. That being said, gently cooked foods are typically easier to digest than raw foods for other reasons. My recommendation would be to lightly steam your veggies for maximum nutritional benefits. If you boil them, use the water as a base for a soup to get all the important nutrients from the vegetables. If you microwave vegetables, use as little water as possible and only heat them for a short period of time. Most of the research I found was on cooking veggies, but I believe these conclusions would apply to all types of food.

And, of course, never microwave in plastic. Glass or non-leaded microwaveable ceramic is best.

Sources

“Effects of different cooking methods on health-promoting compounds of broccoli” by Gao-feng Yuan, Bo Sun, Jing Yuan, and Qiao-mei Wang (2009

“The Claim: Microwave Ovens Kill Nutrients in Food” by Anahad O’Connor (New York Times, 2006)

www.medicinenet.com

Coconut Water Confusion

Dear PWN,

What do you make of the recent news that coconut water is just sugar water and doesn’t really help you rehydrate? I’ve been using it in smoothies. Do I need to stop?

-Alice, St. Louis, MO

Alice & other readers,

Coconut water, by definition, is the clear liquid inside a young coconut. As the coconut matures, the liquid decreases and is replaced by coconut meat. Therefore, young coconuts have the most water.

There are naturally occurring sugars found within pure coconut water. In fact, most of the calories in a serving of coconut water come from its sugar content. Coconut water also contains high levels of potassium and other electrolytes, which is why it is often marketed as a solid beverage choice for athletes.

People who consume many servings of fresh fruits and vegetables per day will have no issue getting ample amounts of electrolytes and potassium into their diet. Therefore, water works fine for hydration. However, after a hot yoga class, long training run, or intense workout, a serving of coconut water can help quickly replenish electrolytes. The sugar in coconut water also provides energy.

So, to answer your question, coconut water does help you rehydrate. All of its sugars are natural, but they are still sugar. In terms of sports drinks, coconut water is the best. However, I recommend pure water still be your beverage of choice. Save the coconut water for those days when you feel especially depleted: right before or after an intense workout; those mornings when you wake up feeling like you possibly had one too many cocktails the night before; or other times of dehydration.

If you simply enjoy the taste, that is fine! Just be sure to consume coconut water with some protein and healthy fats so your blood sugar stays under control, and watch your sugar intake throughout the day.

Finally, beware of flavored coconut water or those claiming to be energy drinks. Read their labels carefully – any ingredient other than “pure coconut water” can mean added sugars or flavors. These do not contribute health benefits and can increase the sugar content unnecessarily.

I hope this clears things up a bit! Thanks for raising the issue. It can be easy to get caught up in the latest food or beverage trend!

Have You Seen This?

I’ve seen these futuristic, video game-like machines twice in the past week, so I figured it was time to do a little research and figure out what was new in the world of pop (I’m from the Midwest. It’s pop to me).

Meet Coca-Cola Freestyle. Maybe you already have… according to Wikipedia, these touch screen soda dispensers were released by Coca-Cola to stores in June of 2010. But I am old, and my kid is still too young, so I am out of touch with what's hot in the junk food world.

These machines offer over 100 different flavors of beverage, and market them as being “made for you.” It’s a genius idea. If I were seven years old, hanging out at a Freestyle machine and choosing flavors with my friends would probably be really fun and cool. It’s like this generation’s version of going to 711 and mixing all the soda fountain flavors together into one big plastic cup.

Nutritionally, though, these machines are a disaster. Apparently there are over 60 diet and/or low-calorie flavors, which screams artificial sugars. And the ones using real sugar are still packed with real sugar, as well as artificial flavors and colors.

You know all of this though. Soft drinks are very harmful to our health, whether we are drinking an original Coke or a Caffeine-Free Diet Coke with Raspberry Orange flavoring. I just wanted to write about this to bring it to your attention. Just when it seems like we are gaining some momentum in the world of nutrition with things like organic gardens at elementary schools and gluten-free options on chain restaurant menus, something like this pops up. To me, the Coca-Cola Freestyle machine is just a reminder that we need to continue to educate ourselves and our families on the importance of nutrition, and make a consistent effort to incorporate fresh, healthy foods into our diets. No matter how much publicity healthy eating receives, there will always be equally strong pulls in the other direction. The more we know, the easier it is to choose wisely!