There’s no hiding the benefits found in fruits and veggies, like antioxidants, fiber, and other essential vitamins and minerals. Yet, when you cook those brightly colored foods, like bell peppers, leafy greens, broccoli, and more, you run the risk of deleting some of those nutrients through the cooking process and heat, whereby your body cannot absorb the maximum amount.
Luckily though you can increase absorption and retain nutrients by choosing specific cooking methods that work in your favor, without adding any effort on your part! And these better-for-your-health cooking methods happen to make some pretty delicious meals too, like stir-fry, roasted veggie medleys, and more.
Here are a couple of ways to retain the nutrients in your produce, according to dietitians. This way you get the greatest bang for your buck and can reap those amazing health benefits with each bite!
Master the stir fry
Stir-frying is a great cooking method and helps to retain a lot of the veggie’s nutrition, but it’s important to use the right oils. “For this type of high heat cooking I would recommend using avocado oil because it has a higher smoke point, therefore it can better withstand high heat vs. olive oil,” says Maggie Michalczyk, MS, RD.
Plus, the short cooking time when you stir fry allows the veggies and meats to retain more of their nutrient value as opposed to other methods like baking, boiling, roasting, or frying. The type of nutrients that stir-frying helps retain vary depending on the vegetable, though. One example of how temperature can make a difference is that spinach should always be sautéed on low heat, otherwise it will lose a lot of its vitamin C content, says Michalczyk.
Or stir-fry your veggies with a bit of olive oil, if you can go for a lower-heat option. “This cooking method helps to retain the nutrients in the produce (unlike boiling and simmering, where nutrients are lost in the cooking water),” says Gabrielle McGrath, MS, RD, LDN.
“Additionally, the healthy fats in the oil actually improve the absorption of fat-soluble vitamins, like vitamin A in sweet potatoes and carrots,” McGrath says. Plus stir-fry dishes are easy to make—in a matter of minutes—in a wok, and you can use a variety of proteins and veggies, as well as sauces, so you never get bored.
Boiling can definitely deplete healthy nutrients, such as vitamin A and fat-soluble nutrients, as explained above, as well as others too. “By preparing vegetables and not boiling them, water-soluble nutrients, especially vitamin C and the B vitamin folate are retained,” says Kelly Jones MS, RD, CSSD, LDN.
“When boiling, those nutrients can be leached out into the water in great amounts, and therefore not eaten,” she says. What’s more, potassium may also be lost in greater amounts from boiling, making a stir-fry, for example, a better option. You need potassium to boost electrolytes, recover after a workout, prevent muscle cramping, and to maintain proper water balance in the body.
Generally, the longer that vegetables are submerged in water, the more water-soluble vitamins and minerals leach out. Don’t fret though, this isn’t an issue when you’re going to be consuming the liquid too. “If you’re boiling the vegetables to make a soup, you can recover those nutrients because you’re not draining the liquid used to cook the vegetables,” suggests Charlotte Martin, MS, RDN, CSOWM, CPT.
Boiling is the method that leaches out the most nutrients. However, steaming vegetables for too long can also cause this effect though not to as great of an extent as with boiling.
Roasting is a great low-maintenance method for cooking vegetables. The key is to ensure you don’t overcook them, or else you won’t get the benefits and it might taste burnt and rubbery. “Once vegetables start to lose their texture and brightness, it’s an indication that they’ve started to lose antioxidant capacity as well,” says Jones.
With all of these methods though, it’s important to keep perspective. Cooking vegetables at high temperatures for longer periods of time can result in more nutrient loss, but it doesn’t mean you shouldn’t roast your vegetables. Whatever the method, adding vegetables helps to create a healthy dish. “Roasting vegetables is a healthy way to cook them because it doesn’t require a lot of fat (i.e. butter or oil) to do so. Plus, it doesn’t require any water, so you won’t lose much of the water-soluble vitamins,” says Martin.
Embrace healthy fats
Whether you cook vegetables in fat, or just include fat at that meal in some other way, you’re maximizing absorption of fat-soluble vitamins, A, D, E, and K as well as fat-soluble phytochemicals, such as terpenoids. “Without fat at meals, you will not benefit from these important nutrients,” says Jones.
Yet, go for healthy fats, not butter and ghee! Think olive oil, avocado oil, coconut oil (in moderation, as there is more saturated here), and grapeseed oil. These all have good heart-healthy and unsaturated fats to boost your health and lower inflammation, and they have different smoke points to accommodate different cooking methods and heat levels.
Plus, “some studies have shown that olive oils or other healthy oils (like avocado oil or safflower oil) transfer their antioxidative properties to the foods that are cooked in them thus enhancing the nutritional value of the foods,” says Michalcyzk.
Olive oil is a monounsaturated fatty acid, which is a good fat known to increase the good cholesterol (HDL) in our bodies and decrease the bad cholesterol (LDL). Olive oil also contains vitamin E and vitamin K.
Be cautious with the C
Vitamin C not only can be leached out into water, but it is also heat sensitive. This means at very high temperatures, vitamin C is lost. “For this reason, vitamin C rich produce, such as peppers and greens, should not be overcooked, especially with methods such as grilling,” says Jones.
Polyphenol phytochemicals might also be at risk of depletion of nutrients when exposed to high heat, as well. “They are rich in foods such as broccoli, artichokes, spinach, and asparagus,” says Jones.
You do not always need to go with fresh fruits and veggies, especially when you want to eat something that is in its offseason. It won’t be as ripe fresh anyway, and it’ll be more expensive in the supermarket.
By going for frozen, they will last longer, be cheaper, and have more nutrition per bite, too! “Remember frozen vegetables are just as nutritious as fresh—and sometimes even contain more nutrients than fresh as frozen vegetables are flash frozen right after harvest,” says Juliana Dewsnap, RD, LD, CPT.
“I personally can’t always use all my fresh vegetables before they go bad, so I make sure to stock my freezer with frozen options (and that way, I always have vegetables at the ready),” she says.
To be fair, “when fresh produce is local, it packs the most nutritional power since there is a shorter time from harvest to consumption, and therefore less time for antioxidants to diminish,” says Jones.
Yet, for many climates in the winter months, fresh local produce is limited, and purchasing frozen, or even canned, vegetables and fruits can mean more nutrients are retained. Fruits and vegetables are usually picked and frozen or canned within hours, Jones explains. If you do canned, buy unsweetened (not drenched in syrup)—especially fruit.
Avoid the grilling overkill
Similar to roasting, be sure you don’t overcook on the grill. “While charing meats can produce carcinogenic heterocyclic amines, those compounds are not a product from charred produce,” says Jones. “You’ll just have reduced vitamin C and similar antioxidant phytochemicals,” she says.
Choose cooked more than not
So long as vegetables aren’t boiled or overcooked, most nutrients have a greater ability to be absorbed versus when they are ingested as raw vegetables, says Jones. So, it’s best to cook them to bring out those nutrients! Just be sure to choose the right methods to get the most benefits possible.
What’s more, “heating food like tomatoes, carrots, and sweet potatoes actually makes the beta carotene (precursor to vitamin A) in them more bioavailable when cooked as opposed to raw,” adds Michalczyk. And foods like mushrooms, asparagus, and cabbage actually provide more nutritional antioxidative compounds when they are cooked, as opposed to raw, she adds.
Vegetables rich in water-soluble vitamins, especially vitamin C and the B vitamins, are typically more sensitive to cooking and prone to nutrient loss. “For example, raw red peppers provide more vitamin C but on the other hand, some nutrients in produce are bound in the cell walls, and cooking can help release those nutrients so that your body is better able to absorb them,” says Martin. For example, tomatoes release more lycopene, a disease-fighting antioxidant, when cooked, she adds.
Head to the kitchen with these take-home messages
Keep in mind though, the important thing here is to simply eat more veggies, period!
If the idea of having to eat your favorite veggies raw or cooked in a specific way makes you want to avoid eating them altogether, then forget about it. You’ll still get plenty of nutrients no matter which forms and/or method of cooking you choose.