The Veggie Debate: Does Cooking Vegetables Destroy Nutrients and the Best Ways to Cook Them

Vegetables are one of the healthiest foods you can choose. Some people downright hate them, while some love them. Others learn to enjoy them in time. While others may tolerate them if they’re cooked the right way. 

Veggies contain a lot of nutrients. But is the same true when you cook them? Or does cooking vegetables destroy nutrients? And what are the best ways to cook veggies to preserve their nutrients? We’ll talk about all this and more.

What nutrients do veggies contain?

Vegetables are some of nature's most nutrient-dense foods. They are readily available in vitamins, minerals, and antioxidants. Plus, veggies have dietary fiber, which helps keep your gut healthy.

The exact vitamins you find on your plate depend on the veggies you choose. If you’re looking for vitamin A, carrots, sweet potatoes, spinach, kale, butternut squash, and bell peppers are your friends.

For vitamin K, you can choose from kale, spinach, broccoli, Brussels sprouts, cabbage, or asparagus. Vitamin C is in most veggies, but you should pay extra attention to broccoli, Brussels sprouts, and bell peppers.

Lentils, asparagus, and spinach can give you plenty of vitamin B9, while potatoes and avocados are your friends if you need more B6.

Veggies are also abundant in minerals. If you want to boost your magnesium intake, choose spinach, Swiss chard, peas, or kale. Chickpeas, lentils, spinach, and kale can give you an iron boost, while for calcium, prioritize broccoli, kale, bok choy, and collard greens.

Sweet potatoes, pumpkin, tomatoes, bell peppers, and onions are only some of the vegetables that are very high in antioxidants.

You shouldn’t overlook other veggies, either. Each contains plenty of vitamins and minerals, dietary fiber, and antioxidants. They all contribute to your general well-being, can boost your immunity, improve your digestion, and help you be healthier.

Does cooking vegetables destroy nutrients?

Cooking alters the nutrient content of vegetables. Sadly, in most cases, that means fewer vitamins, minerals, or antioxidants. On the other hand, cooking can make foods easier to digest, and your body can absorb more nutrients.

Research shows that most water-soluble vitamins, specifically C and B, take the biggest hit during cooking. For instance, boiling spinach for 30 minutes will remove 95% of its vitamin C content.

Cooking also reduces some fat-soluble vitamins, such as A, D, E, and K.

Minerals can be slightly more resistant, but some, such as magnesium, calcium, and potassium, don't do well with cooking. Antioxidants, such as beta-carotene, can also take a hit when the food is cooked instead of when you eat it raw.

Total vs. absorbed nutrients

When we think of veggies, we’re tempted to look at their profile when they’re raw. If we take it one step further and look at their nutritional profile after cooking, we’ll naturally conclude raw is better. Research doesn’t always agree, though.

A 2009 study published in the American Journal of Clinical Nutrition compared a group of women who ate a Western diet (with cooked veggies) and one who ate raw veggies. Their focus was on the intake of beta-carotene.

Looking strictly at micros, the group eating only raw food had the highest intake of nutrients. However, those eating cooked veggies absorbed more beta-carotene. The conclusion? We don’t always absorb all the nutrients we eat. We need to aim to absorb as many nutrients as possible for maximum benefits. And often, we absorb more from cooked foods.

Can cooking boost the nutrient content of vegetables?

Cooking alters the nutrient content of veggies—but that’s not always a bad thing. While most vitamins, minerals, and antioxidants will lower after cooking, in some veggies, they will increase.

Cooked mushrooms contain about twice as much potassium, zinc, magnesium, and niacin as their raw counterparts.

The vitamin A in carrots may not be the biggest fan of heat, but a study showed that cooking carrots can increase their concentration of carotenoids by 14%.

Tomatoes, whether you consider them a fruit or a veggie, also do well when cooked. Heat increases their lycopene concentration, an ingredient that helps lower the risk of heart disease or cancer.

What are the best ways to cook veggies?

We know cooking changes the nutrient composition of veggies. But did you know research shows how you cook them can have a powerful impact on their nutrient content, too?

Steaming

Steaming is probably the best cooking method for nutrient preservation. Do you remember our friend, spinach, which can lose 95% of its vitamin C when boiling? Studies show that through steaming, it only loses up to 15% of the vitamin C.

The downside? Steamed veggies aren’t the tastiest, but you can season them and even add some olive oil or butter after cooking.

Boiling

This may be the most popular way to cook veggies, but unfortunately, it is the one that will lead to nutrient loss in many of them. Water-soluble vitamins especially tend to disappear when you cook your food in water.

B vitamins are also sensitive to heat; you can lose up to 60% of them when you boil veggies.

There is some good news, though. If you also consume the water in which you boil the veggies—hello soup or veggie broth—you will get up to 100% of the minerals and 70% of the vitamins.

Roasting or baking

A less common way to cook veggies, baking and roasting, can retain over 80% of most vitamins. The big exception here is B vitamins, which will take a hit because of the high temperatures. This technique requires little to no oils, so if you’re trying to reduce your fat intake, it could be a good choice for you.

Sautéing or stir-frying

Unlike roasting or baking, sautéing or stir-frying involves cooking your veggies in a pan. You’ll need to use oil this time, but that doesn’t mean your meal will be unhealthy. Humans need some good fat in their diets now and then.

The heat is pretty high when sautéing, but the process usually takes a short time, which means veggies will preserve more nutrients.

A study found that stir-fried carrots contain 6.5 times more beta-carotene than raw ones. Lycopene in tomatoes is another nutrient that significantly increases with this cooking style.

Pressure cooking

Pressure cooking with tools like the Instant Pot is a relatively new addition to our kitchens, so we don’t have as many studies on it.

Looking back at our friend, spinach, ten minutes in the pressure cooker reduces its vitamin C content by 90%. The good part, though, is that you’ll rarely need to pressure cook your spinach for that long, so you may save more of those nutrients.

Tips to minimize nutrient loss while cooking

Some veggies are best eaten raw; others need to be cooked. Some lose their nutrients while you cook them, while others get a boost. Is there anything you can do to minimize nutrient loss while cooking? Here are a few tips.

• Steam, don’t boil. It’s healthy and preserves most of your vitamins and minerals.
• Use minimal water. If you choose to boil veggies, use as little water as possible.
• Don’t overcook veggies. Do 2 extra minutes really count when cooking veggies? Yes, they do. Overcooking veggies will not only make them taste worse, but it will also lead to more nutrient loss.
• Add lemon or vinegar while cooking. The acidity can help preserve nutrients in some veggies. Stay away from baking soda, though. It is alkaline and will have the opposite effect.
• Peel veggies only after you cook them. This will help retain more nutrients and will even help them taste better.

Bottom line

Cooking may alter your veggies’ nutrient content, but that’s not always a bad thing. Many times, the nutrient percentage will lower drastically, while in others, it will increase. Plus, cooked veggies are easier to digest, and your body will absorb more nutrients.

The key takeaway? Eating veggies, cooked or raw, is better than not eating them at all. Whether you get 100% of the vitamin C in spinach or only 10%, it will still be better than none at all.

And if you’re ever in a situation where you just can’t eat healthy, supplements could come to the rescue. We always advocate for getting nutrients from foods rather than supplementing, but we also know that sometimes that’s simply impossible.

The Green Superfood Powder Mix can be a lifesaver in such moments. Containing a multitude of vitamins, minerals, and antioxidants, this powder mix can give you a nutrient boost on days when your diet is less than ideal.

Health/Medical Disclaimer

This blog post does not provide health or medical advice. This blog post is for informational and educational purposes only and is not a substitute for professional health or medical advice. Before taking any actions based upon such information, we encourage you to consult with the appropriate medical and healthcare professionals. We do not provide any kind of health or medical advice. The use or reliance of any information contained on this blog is solely at your own risk.

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https://pubmed.ncbi.nlm.nih.gov/19650196/

https://pubmed.ncbi.nlm.nih.gov/21923982/

https://pubmed.ncbi.nlm.nih.gov/15927929/