Including a wide variety of vegetables in your diet is vital for promoting optimum health. Both raw and cooked vegetables provide fiber and essential vitamins and minerals, such as potassium, folate, and vitamins A, C, and E. But according to Dr. Amy Myers, some vegetables offer superior health benefits when they are cooked. “Cooking can alter their chemical composition and that could be a good thing,” she says.

Here are some vegetables that are nutritionally more powerful when cooked:

1. Asparagus. Important nutrients in this popular vegetable may be trapped in living cells, which is why cooking helps release these nutrients from cell walls, making them more easily absorbed by the body when ingested. Cooking asparagus breaks down its cell walls, making vitamins A, B9, C and E more bioavailable, says Medical Daily.
2. Carrots. While raw carrots offer more vitamin C, your body absorbs significantly more beta carotene from carrots when cooked, says Myers. Beta carotene is converted to vitamin A in the body to support a healthy immune system. “I advise cooking your carrots to get the full benefits of the beta carotene,” she says.
3. Mushrooms. These healthy veggies contain potassium, niacin, zinc, and magnesium. Eating mushrooms as a cooked vegetable can make these nutrients more bioavailable. One cup of cooked, white mushrooms has about twice as much of these nutrients as a cup of raw mushrooms.
4. Spinach. Leafy greens are beneficial for your body whether eaten raw or cooked. However, Myers advises cooking spinach to better absorb the minerals calcium and iron. The beta carotene in spinach is also more available to the body when cooked. “So, if you are on the fence between raw versus cooked spinach, I’d advise opting for cooked,” she says.
5. Tomatoes. Cooking, using any method, increases the antioxidant lycopene in tomatoes, says Medical Daily. Lycopene has been associated with a lower risk of a range of chronic diseases including heart disease and cancer. The increased lycopene comes from the heat breaking down the thick cell walls of the fruit. In fact, cooking tomatoes for 30 minutes increases their lycopene content by more than 50%.
6. Bell peppers. Heat helps break down the cell walls of peppers, releasing immune-boosting antioxidants, including beta carotene and lutein. However, steaming peppers can reduce their vitamin C content so roasting them is a better option.
7. Kale. According to Medical Daily, kale is healthier when lightly steamed as this method deactivates enzymes that prevent the body from using the iodine it needs for the thyroid, which helps regulate your metabolism. According to EndocrineWeb, even though there’s been some speculation that eating kale and other cruciferous vegetables can negatively affect the thyroid, proper cooking and eating them in moderation reduces that risk.
8. Green beans. Popular and inexpensive green beans have higher levels of antioxidants when they are baked, microwaved, grilled, or even fried as opposed to boiled. Using less water when cooking vegetables, in general, prevents nutrients from leaching.

Myers says the best way to cook vegetables for optimum health benefits is to cook them quickly. “The less time you expose a vegetable to heat, the more nutrients it keeps,” she says. This means preparing raw vegetables into large chunks and cooking just until they are al dente, not mushy.

You can air fry, steam, sauté, or pressure cook vegetables to retain maximum nutrients.

“Pressure cooking is the top-rated method for cooked vegetables in terms of nutrition retention,” she says. “In fact, cooked vegetables with pressure cooking retain 90% to 95% of their nutrients. Because steam and heat can’t escape, the vegetables cook quickly at a lower temperature than other methods.”