Does Cooking Vegetables Destroy Their Nutrients? – FOXOLIFE Blog

Does Cooking Vegetables Destroy Their Nutrients?

To Cook or Not to Cook Your Vegetables?

I will admit, I spent a good month in college trying a “raw” diet, which meant cutting out all processed and cooked foods. I had stumbled upon the diet after finding a cookbook among the library shelves claiming the numerous benefits of eating raw food. Game to try anything that promised to make my energy levels higher, skin more glowy, and digestion strong as an ox, I checked out the cookbook and headed to the grocery store.

What did I learn after weeks of cold salads, raw veggie wraps, and handfuls of seeds and nuts? Well, I was eating a LOT more fruits and vegetables, but I didn’t really feel any better and on top of that, the diet was expensive and unrealistic—especially for a college kid. My digestion was actually worse, and I just wanted to eat something warm. Let me tell you, there’s not much comfort in a cold salad.

So, my failed diet experiment aside, were those cookbook authors really onto something? They claimed that cooking our fruits and vegetables destroys key nutrients…but does it? Today on the blog, I dig into the research to find out how cooking impacts nutrient levels in foods! 

How Does Cooking Vegetables Impact Their Nutrients? 

Long story short: the answer to this question is a bit of a mixed bag. Some foods increase their bioavailability of certain nutrients after cooking them, while at the same time, other nutrients may decrease.

Take carrots, for example. One study showed that cooking carrots actually increased their amount of beta-carotene, while at the same time decreased their levels of Vitamin C. Turns out, both the type of nutrient and the cooking method have a large effect on what happens to those nutrients. 

These Nutrients Have Been Found to Increase with Cooking

  • Lycopene: A study published in the Journal of Agriculture and Food Chemistry found that cooking actually boosted the amount of lycopene found in tomatoes. And, guess what? According to another study that followed 198 subjects on a strict raw diet, they were all low on lycopene. Lycopene is an antioxidant and has been linked to health benefits ranging from heart health to protection against sunburns and certain types of cancers.
  • Carotenoids: According to this study, boiled and steamed greens showed higher levels of carotenoids, while another study showed higher levels of beta carotene in boiled carrots. Beta Carotene, a form of Carotenoids, are antioxidants and can be converted into Vitamin A when released into your body. This is an especially important nutrient for growth, immune system function, and eye health. 
  • Omega 3 Fatty Acids: This study found that cooking or microwaving fish, like tuna, helped preserve its omega-3 fatty acids, unlike canning—which destroyed it. 

These Nutrients Have Been Shown to Decrease with Cooking 

  • Vitamin C: This vitamin is highly unstable, easily degrades through oxidation and exposure to heat, and dissolves in water, making it hard to withstand any cooking methods. Vitamin C is found in high amounts in broccoli, green and red peppers, and leafy greens to name a few. 
  • Vitamin Bs (thiamin, riboflavin, etc.): This family of vitamins is highly heat sensitive. B vitamins are important for making sure the body’s cells are functioning properly. They help the body convert food into energy (metabolism), create new blood cells, and maintain healthy skin cells, brain cells, and other body tissues.
  • Some minerals like Potassium, Magnesium, Sodium, and Calcium. These minerals are critical in helping our bodies do everything from muscle contraction to nerve transmission and blood pressure regulation.

Another benefit of eating cooked vegetables is that it can be easier on our digestion. A lot of raw vegetables contain high amounts of fiber, which can be hard for our bodies to digest. Cooking vegetables can also break down their cell walls, which makes it easier to absorb some of the nutrients. Some of the vegetables that people have the hardest time consuming raw include cruciferous veggies like broccoli, cauliflower, and cabbage, peas and mushrooms. If you love these veggies, try lightly steaming them first. 

The Best Cooking Methods to Preserve Nutrients 

Not all cooking methods are the same when it comes to preserving the nutrients in your vegetables. Overall, boiling, steaming and (surprise) microwaving seem to be your best options, while frying destroys the most nutrients across the board.  

A January 2008 report in the Journal of Agriculture and Food Chemistry said that boiling and steaming preserves antioxidants, particularly carotenoids, better than frying in carrots, zucchini and broccoli—though boiling was deemed the best. The researchers studied the impact of the various cooking techniques on compounds such as carotenoids, ascorbic acid, and polyphenols.

Of course, time should be taken into consideration as well. The longer a food is cooked, the greater the loss of its nutrients. 

Eat Your Veggies…Any Way You Like Them 

All in all, while cooking a vegetable may make it lose some of its special nutrient properties, it also may enhance some. So, bottom line is it’s important to eat a mix of raw and cooked vegetables to get the full nutritional benefits of these foods. If you can only tolerate vegetables cooked, well that’s better than no vegetables at all. Follow us on social media at facebook and Instagram to learn more about the science of health and aging, and get tips on diet and nutrition.