You probably already know that vegetables are good for you, but what you may not realize is that raw vegetables have different nutrient profiles than cooked ones. In some cases, raw vegetables are better for you; however, some, like tomatoes, provide more nutrition after they've been cooked.
There's really no right or wrong way to eat vegetables, but figuring out which are the healthiest to eat raw and which are better cooked can help you optimize the amount of vitamins, minerals and antioxidants that your body absorbs.
The Loss of Nutrients
Vegetables, of course, are rich in vitamins and minerals. The vitamins in vegetables can be further categorized as fat-soluble and water-soluble. Fat-soluble vitamins, which include vitamins A, D, E and K are more stable, whereas water-soluble vitamins, which include vitamin C and the B vitamins, are more sensitive to cooking.
That's why some people recommend eating vegetables raw to maximize the amount of nutrients you get from them. But there are some vegetables that are richer in the water-soluble vitamins than others. Prioritizing eating these vegetables raw can help up your intake of vitamin C and the B vitamins. On the other hand, you may be better off cooking vegetables that are higher in the fat-soluble vitamins.
Vegetables are also rich in antioxidants, and cooking has significant effect on the antioxidant activity in different kinds. According to a study published in the journal Food Chemistry in February 2018, the antioxidants in some vegetables are destroyed after cooking, while some become more bioavailable. The cooking method you choose also plays a role.
Healthiest Vegetables to Eat Raw
Vegetables that are rich in vitamin C, like broccoli, spinach and lettuce, are among some of the healthiest vegetables to eat raw, since cooking can significantly destroy the vitamin C content.
A study published in Nutrition and Food Science in November 2012 reported that when cooked, vitamin C-rich vegetables lost between 9 and 55 percent of their vitamin C content, depending on the method of cooking. Steaming had the least significant effect, while boiling destroyed the most nutrients. Vitamin C-rich vegetables to eat raw include:
- Brussels sprouts
- Green beans
- Snow peas
The 2018 study in Food Chemistry compared raw vegetables to vegetables cooked through conventional methods or a sous vide method, which involves sealing vegetables in a plastic bag or glass jar and then cooking them in boiling water, and found that the raw vegetables with the highest antioxidant activity include:
- Green bell pepper
- White onion
- Parsley root
Vegetables to Cook
On the other hand, researchers from the report noted that there are some vegetables whose antioxidants become more bioavailable when you cook them. The cooking method matters too, though. Vegetables cooked using a sous vide method had greater antioxidant activity than boiled vegetables. These vegetables include:
Another study, published in the Journal of the Science of Food and Agriculture in April 2014, looked at the beta-carotene content in vegetables and found that cooking has a positive effect. In other words, your body is able to better absorb the beta-carotene from cooked vegetables, like carrots, sweet potatoes, butternut squash and pumpkin, rather than raw ones. That's because cooking softens the plant's walls and allows your digestive system better access to some of the nutrients.
Cook Vegetables Carefully
Of course, eating vegetables cooked is better than not eating any at all, so if raw vegetables aren't your thing or you just prefer to eat them cooked, you can maximize their nutrition by cooking them just enough to soften them (but not so much that they become mushy and soggy).
According to Shayna Komar, RD, a licensed and registered dietitian at Thomas F. Chapman Family Cancer Wellness at Piedmont Health, vegetables lose their nutrients when they're overcooked and eating too many overcooked and processed foods can lead to chronic health problems.
So what's the sweet cooking spot? It's different for every vegetable, but some general tips can help. When cooking, use dry cooking methods or methods that use only a little water, like roasting, baking or steaming, instead of boiling. More nutrients are retained when you use less water and lower heat. Cook vegetables until just tender, not mushy. If you do boil veggies, you can keep the water and use it in soups to save all of those nutrients.
The Academy of Nutrition and Dietetics notes that keeping vegetables in larger pieces when cooking can be beneficial since exposing less surface area translates to fewer nutrients lost. Keeping the skin on certain vegetables, like potatoes, cucumbers and zucchini, can also help.
Not only are a lot of nutrients found in the skin or just underneath it, but the skin also helps the vegetables hold on to more of the nutrients when they're cooked. Just make sure to wash the vegetables thoroughly before cooking.
Tips for Eating Raw Vegetables
Although the exact amount of vegetables you need depends on your age, sex and activity level, general recommendations fall between 2 and 3 cups per day. Both raw and cooked vegetables count toward your intake, but since cooking reduces the volume of leafy greens significantly, the USDA notes that 2 cups of raw leafy greens, like spinach, count as 1 cup toward your intake.
Eating salads is a good way to get in a lot of raw veggies. Start with a base of spinach or kale, then pile on some white onion, green bell peppers and broccoli. You can even up your nutrient intake by adding some cooked vegetables, like roasted beetroot. Top with a dressing made from apple cider vinegar and heart-healthy olive oil, which can help you absorb the fat-soluble vitamins in your vegetables.
You can also prepare a between-meal raw vegetable snack. Combine raw green bell pepper and raw broccoli with a side of hummus, which is rich in protein and can help keep you full until your next meal.
- USDA National Institute of Food and Agriculture Cooperative Extension: "Cooking Methods to Preserve Nutrients in Fruits & Vegetables"
- Piedmont Healthcare: "Health Benefits of Raw Vegetables"
- Academy of Nutrition and Dietetics: "Getting the Most - Flavor and Nutrients"
- University of Kentucky Cooperative Extension Service: "Preserving Nutrients in Food"
- Food Chemistry: "Comparison of Antioxidative Properties of Raw Vegetables and Thermally Processed Ones Using the Conventional and Sous-Vide Methods"
- Nutrition and Food Science: "Effects of Different Cooking Methods on the Vitamin C Content of Selected Vegetables"
- Journal of the Science of Food and Agriculture: "The Effect of Cooking on the Phytochemical Content of Vegetables"
- Food Science and Biotechnology: "Effect of Different Cooking Methods on the Content of Vitamins and True Retention in Selected Vegetables"
- USDA ChooseMyPlate: "All About the Vegetable Group"