If you encounter a raw foodie, they’ll probably tell you that raw vegetables are better for you than cooked ones. Nor surprising, right? A whole movement has been built around the concept that raw foods are healthier and that cooking them destroys their essence and a portion of their nutritional content. At first, glance, that sounds problematic. One reason we eat vegetables is for the nutrients and phytonutrients they offer. Is stocking your crisper with raw veggies and eating them in their natural state the healthiest approach to meeting your body’s micronutrient requirements?
Should You Eat Most of Your Vegetables Raw?
It’s true that cooking destroys some of the nutrients in vegetables. The vitamins that are most unstable with exposure are vitamin C and some vitamins in the B-vitamin family – and not all cooking methods are equal for the preservation of vitamin C. Depending upon the method, cooking destroys from 15 to 55% of the vitamin C in vegetables. So, from a vitamin C standpoint, raw is better. However, vitamin C isn’t the only nutrient you find in vegetables.
Another nutrient you find in green, leafy vegetables and vegetables that are red, yellow, and orange in color are carotenoids. Studies show that carotenoids are antioxidants with anti-inflammatory activity. They help support a healthy immune system and may lower the risk of certain age-related eye diseases, including age-related macular degeneration and cataracts. Carotenoids from fruits and veggies deposit in the back of the eye where they absorb ultraviolet light so there’s less to damage the retina of the eye. Needless to say, we want to get enough carotenoids, especially since some studies also show they may lower the risk of certain forms of cancer.
Raw or cooked? Studies show that absorption of carotenoids from food actually increases when you cook vegetables as opposed to eating them raw. The reason? Heat breaks down the cell walls of plants so that carotenoids are released and are more bioavailable to your body. For example, carrots are a rich source of a carotenoid called beta-carotene. To maximize the amount of beta-carotene your body absorbs, cooking carrots is best. But, it’s not so straightforward. Another healthful component of carrots is polyphenols, a type of antioxidant. When you cook carrots, you destroy some of these compounds that also have antioxidant power. So, raw carrots have unique benefits as well – they’re more antioxidant-rich. With carrots, you win some and you lose some when you cook them.
Tomatoes are packed with another carotenoid called lycopene. Interesting, lycopene has the ability to absorb ultraviolet light that hits your skin. Studies show that it actually has an SPF of about 1.4, so it works in synergy with sunscreen to protect your skin against the sun’s damaging rays. But, to get lycopene’s benefits, it’s best to cook your tomatoes. Cooking increases the bioavailability of the lycopene. Another option is to get lycopene from processed tomato sauces, like marinara sauce or ketchup.
Red peppers are also rich in carotenoids, so you might assume they’re better for you cooked. However, they’re also one of the best sources of vitamin C, a heat unstable nutrient. If you need more vitamin C in your diet, enjoy red peppers raw.
Broccoli is a cruciferous vegetable that’s known for its potential anti-cancer benefits. Broccoli contains compounds called glucosinolates that your body can convert to more powerful, cancer-protective chemicals called isothiocyanates. However, it needs an enzyme called myrosinase to make this critical conversion. Cooking broccoli destroys myrosinase, along with some of the anti-cancer benefits. That’s why it’s best to enjoy broccoli raw or lightly steamed.
Another option is to supply add mustard sauce to broccoli. Mustard contains the enzyme myrosinase. However, the best source of myrosinase is broccoli sprouts. Even frozen broccoli is almost devoid of myrosinase because it’s processed with heat. Add raw broccoli to your salads to take the most advantage of broccoli.
Best Cooking Methods
The way you cook your veggies impacts the nutrients you get from them as well. The worst way to prepare them is with methods that use a lot of water or high heat. For example, steaming for long periods or boiling leads to significant loss of vitamin C. Surprisingly, one of the better methods is to microwave vegetables using a small amount of water. Studies show that microwaving can retain as much as 90% of a vegetable’s vitamin C content. Pressure cooking, too, helps preserve vitamin C.
With the exception of broccoli, due to loss of myrosinase, frozen vegetables retain a lot of nutritional value. That’s because they’re harvested at the peak of freshness and the nutrients are locked in when they’re frozen. Fresh vegetables lose nutrients during transport and when they set on store shelves.
The Bottom Line
Raw vegetables versus cooked vegetables – which is healthier? It depends on the vegetable and the cooking method. The best way to maximize the health benefits you get from veggies is to eat a variety of them, both raw and cooked. Know which vegetables are better for you raw and which offer more nutrition cooked. For example, eat broccoli and red peppers raw, but enjoy tomatoes and carrots cooked. How about greens? You’ll get more vitamin C if you eat them raw but more carotenoids if you cook them. So, vary the types of vegetables you eat and the way in which you prepare them to maximize the health benefits.
Don’t depend on cooked vegetables to be a reliable source of vitamin C since vitamin C is so heat unstable. Add fruit to your diet and eat vitamin-C rich vegetables, such as red peppers and bell peppers, raw. The vitamin content of the fruit will make up for any loss of vitamin C from the cooked vegetables you eat. If you want a concentrated source of vitamin C, look for camu-camu powder or acerola powder, derived from two fruits that are among the best-known sources of vitamin C.
New York Times Well. “Ask Well: Does Boiling or Baking Vegetables Destroy Their Vitamins?”
American Optometric Association. “Nutrition and Cataracts”
Journal of Food Science. View. Issue TOC. Volume 77, Issue 10. October 2012. Pages C1109–C1114.