To get the most out of the veggies you consume, it pays to learn the best ways to prepare them. Learn more about how these 11 cooking methods may impact the potency of the vitamins and minerals found in fresh produce. That said, eating veggies in almost any form – battered and deep fried is one exception – is much healthier than leaving them off your plate.
Do Raw or Cooked Vegetables Have More Nutrients?
- Fiber
- Calcium
- Potassium
- Magnesium
- Vitamin A
- Vitamin C
- B vitamins
- Iron
- Vitamin K
- Vitamin E
“Fresh and cooked vegetables both play an important role in a balanced diet,” says Sharniquia White, RDN, a trained chef and nutrition expert in Greensboro, North Carolina. “Raw vegetables often provide the highest levels of heat-sensitive vitamins like vitamin C and some B vitamins, while cooking can enhance the absorption of others, like vitamin A.”
Longer cooking times for veggies can reduce the nutritional quality, but some veggies are also more susceptible to nutrient changes from cooking than others.
Vegetables That Tend to Lose More Nutrients When Cooked
Some vegetables that are likely to be negatively impacted by cooking include:
- Broccoli and spinach: These tend to lose vitamin C.
- Greens like chard, crown daisy, and mallow: Research shows that cooked greens often lose vitamin K.
- Potatoes, sweet potatoes, and carrots: These root veggies may lose vitamin E with cooking.
Vegetables With Higher Nutrient Bioavailability After Cooking
On the other hand, cooking gives some veggies a boost in nutritional bioavailability. Here are some vegetables that may be enhanced by cooking.
- Tomatoes By breaking down plant cell walls, cooking increases the bioavailability of beta-carotene in carrots and lycopene in tomatoes, says Karolin Saweres, RDN, the founder of My Nutrition and Me, a weight management and disease prevention practice based in Cincinnati.
- Asparagus Cooking asparagus increases its levels of antioxidant phenolic compounds.
- Mushrooms Microwaving or grilling mushrooms may enhance their antioxidant activity, too.
- Carrots Though some nutrients in carrots may decrease with cooking, others may be enhanced. The body more easily uses beta-carotene from cooked carrots than raw ones.
How Different Cooking Methods Affect the Nutrients in Vegetables
Here’s what to know about each cooking method.
Boiling
“If you do decide to boil your veggies, pairing the method with a shorter cook time or repurposing the cooking liquid can help mitigate nutrient loss,” Leverich says.
Steaming
“Compared to boiling, steaming tends to retain more antioxidants and natural color – a good visual cue that nutrients are still intact,” she says.
Microwaving
The microwave isn’t best known as the kitchen device for healthy meal prep, but as it turns out, this quick-cook kitchen staple is surprisingly good at retaining the nutrients found in vegetables.
“Microwaving consistently ranks as one of the best methods for retaining nutrients in vegetables,” Leverich says. “Its rapid cooking time and minimal water use help protect heat- and water-sensitive vitamins.”
In one recent study of numerous cooking methods, microwaving had the least impact on vitamin C, preserving 90 percent of its original content. Ultimately, the study concluded that microwaving was the most effective cooking method for retaining the nutritional value of vegetables.
Sautéing and Stir-Frying
Sautéing uses medium heat to cook foods, while stir-frying uses higher heat. When the amount of oil you add is kept in check (think a 1 tablespoon serving of olive oil or less), White says both cooking methods are great for preserving nutrition.
“Quick cooking at high heat helps reduce overall nutrient loss,” White says. “Healthy oils [such as olive oil] support the absorption of fat-soluble vitamins (A, D, E, and K), and compounds like carotenoids in carrots, spinach, and peppers are absorbed better when fat is present.” But if you turn up the heat to sauté or stir-fry, White says to keep cooking time short “to help avoid excessive heat that can break down nutrients.”
Grilling and Broiling
Though grilling uses high heat, this cooking style is less likely to leach the healthy compounds out of your veggies than some other options.
“From a nutrition standpoint, grilling uses high heat with no added water, which helps retain many nutrients that are normally lost through boiling or simmering,” says Leverich. But the intense heat can break down some heat-sensitive vitamins, like vitamin C and B vitamins. “Still, when it comes to maximizing both taste and overall veggie intake, grilling is a strong choice,” she says.
Broiling also exposes foods to a strong heating element, which can be beneficial for some types of veggies and less so for others. While broiling does not involve water, its intense heat can break down water-soluble vitamins such as C and some B vitamins, Leverich says.
“That said, it can be a great choice for beta-carotene-rich vegetables like sweet potatoes or squash, since the heat actually helps make those nutrients more available.”
Baking and Roasting
Despite the higher temps used to heat veggies in the oven, this method doesn’t excessively diminish veggies’ nutrient density, says Saweres…