Nutrient Retention in Cooked Vegetables—Is Raw Always Better?

As we all know, fruits and vegetables are excellent sources of vitamins, minerals, antioxidants, and fiber, and for this reason a diet rich in these foods is highly recommended by experts for its many health benefits, including lower blood pressure, decreased risk of heart disease and stroke, better weight management, and overall decreased risk of all-cause mortality.1 It isn’t always clear, however, whether a fruit or vegetable is more nutritious in its raw form or after it has been cooked. Proponents of raw food diets claim that cooking food destroys important nutrients and enzymes.2 But, while cooking can destroy or greatly reduce certain water-soluble and heat-sensitive nutrients, such as vitamins A and C and some types of antioxidants, it can also enhance or increase availability of heat-tolerant or fat-soluble nutrients, such as beta-carotene, vitamin E, and vitamin K.3 Additionally, cooking vegetables can make them easier to eat and more palatable for many individuals. The method of cooking (e.g., boiled, steamed, roasted, microwaved) and amount of cooking time can also impact the degree of nutrient loss, and even this can vary from vegetable to vegetable.3 Here we review the nutrient content of some common vegetables in raw form and the effects that different types of cooking have on their nutrition profile.


Raw beetroot is an excellent source of phenolic, flavonoid, and carotenoid compounds; dietary fiber; folate; and manganese and is a good source of vitamin C, copper, and potassium.4 It’s hard to resist these ruby red roots, but can you still get all those nutrients after a beet has been cooked? In a study that examined the effect of steaming, pressure-cooking, baking, and boiling on bioactive compounds in beetroot, researchers measured total phenolic compound content, pigment content (anthocyanins), flavonoid content, and betalain content of beets before and after cooking.5 According to results, the antioxidant activity of raw beetroot was 57.63 percent, and no significant changes to this activity were observed following any of the cooking methods. Total phenolic compound content and anthocyanin content also did not significantly change following any of the cooking methods. Carotenoid concentration, however, was reduced more than 50 percent, compared to raw beetroot, in pressure-cooked beets, but not significantly so in the other cooking methods, and flavonoid and betalain content was reduced in all cooking methods, but especially so in pressure-cooked beets, compared to raw beetroot.5 Bottom line: Overall nutrient content decreases in beetroot when cooked, and the longer beets are cooked, the more nutrient loss occurs.6 However, cooked beetroot is still a great source of several vitamins, minerals, and fiber, if not to the same degree as raw beetroot, and all that great antioxidant activity appears to remain unchanged. Raw or cooked, beets are good nutrition!


Raw broccoli is an excellent source of vitamins C and K and a good source of vitamins B2, B5, and B6.7 But what does cooked broccoli have to offer? In a study that evaluated the effect of different cooking methods on vitamin content of several vegetables, including broccoli, researchers observed that boiling or blanching broccoli destroyed the vitamin C content, but when microwaved, broccoli was able to maintain up to 90 percent of its vitamin C content.8 This suggests that using minimal water and cooking for shorter time periods can result in higher vitamin C retention. Vitamin K, vitamin E (α-tocopherol), and beta carotene content, on the other hand, increased in broccoli when cooked across several methods of cooking.8 Researchers believe this may be because the heat from cooking breaks down the plant cell wall, releasing these nutrients for better bioavailability.8 With the exception of vitamin C, it appears that the overall nutrient content of broccoli increases with cooking.8,9 Microwaving and/or using minimal water and short cooking times appear to better preserve the nutrients in broccoli compared to boiling or blanching.


Raw carrot is an excellent source of vitamin A, especially alpha and beta carotene, fiber, and vitamin K and is a good source of the B vitamins (except B12), vitamin C, vitamin K, copper, manganese, and potassium.10 For many people, nothing quite beats the crunchy texture and sweet taste of a raw carrot, but for some, biting and chewing a raw carrot is difficult or simply unpalatable. But do cooked carrots pack the same nutritional punch as their raw counterparts? In the same study that evaluated the effect of different cooking methods on vitamin retention in a group of vegetables, including carrot,8 researchers observed that boiling, blanching, or steaming carrot destroyed its vitamin C content, whereas a microwaved carrot retained over 90 percent of its vitamin C content. In contrast to broccoli, however, vitamin E and beta carotene were drastically reduced in carrot following any method of cooking. Another study showed similar results, with carotenoids being drastically reduced in carrots following any type of cooking method.11 Overall, it appears cooking carrots in any way reduces nutrient content, especially carotenoids, but cooked carrots still provide nutrients, albeit in lesser amounts.12 Bottom line? Raw carrot is a nutrient-dense food, whereas cooked carrots lose a lot of their nutrients; however, cooked carrots are still a healthy food choice. If you prefer cooked over raw, consider using minimal water and a quick cooking method, such as a microwave, when preparing your carrots; this will preserve more nutrients than boiling, blanching, steaming, or long cook times.


Raw spinach is an excellent source of carotenoids, folate, vitamin K, and fiber and a good source of vitamin A, vitamin C, and magnesium.15 Like other dark leafy greens, spinach is well recognized for its antioxidant properties, and is commonly consumed in its raw form. But what nutritional benefits does cooked spinach offer? As with many other vegetables, blanching, boiling or steaming spinach significantly diminishes its vitamin C content.3 Similar to carrots and broccoli, however, microwave cooking retained at least 90 percent of vitamins C and K content in spinach, compared to blanching, boiling, or steaming.3 On the other hand, cooking spinach by any method resulted in significant increases in vitamin E and beta carotene bioavailability.3 Another study showed that while boiling spinach significantly decreased folate content, steaming spinach did not affect folate content at all.16 In summary, raw spinach provides many important nutrients; cooking spinach increases its vitamin E and beta carotene bioavailability. Microwaved spinach retains at least 90 percent of its vitamins C and K, and the heat boosts its vitamin E and beta carotene bioavailability. As with other vegetables, when cooking spinach, use only a little water and keep cooking times very quick to retain and even increase its nutritional content.

Sweet Potato

Raw sweet potato is an excellent source of vitamin A, especially beta carotene, the B vitamins, especially B5 (but not B12), fiber, copper, manganese, and potassium and a good source of magnesium.13 Unlike white or yellow potatoes, sweet potato can be safely consumed in raw form, but is, arguably, more palatable in its cooked form. So how does a cooked sweet potato’s nutrition profile stack up to its raw form? Researchers compared phenolic profiles, carotenoid profiles, and antioxidant activities of raw and cooked sweet potatoes. Total phenolic content (TPC), monomeric anthocyanin content (MAC), total carotenoid content (TCC), 2-diohenyl-1-picryhydrazyl (DPPH) free radical scavenging capacities, and ferric-reducing antioxidant powder (FRAP) were measured. While all cooked sweet potatoes exhibited significantly lower TPC, MAC, TCC, DPPH, and FRAP values, compared to raw sweet potatoes, researchers noted that steaming was best for retaining TPC, roasting was best for retaining anthocyanins, and boiling was best for preserving carotenoids.14 Bottom line? Though nutrient content does decrease in sweet potatoes when cooked, they are still a good source of many nutrients, especially carotenoids. 


Raw tomato is an excellent source of lycopene, alpha and beta carotene, vitamin C, vitamin K, copper, and potassium and a good source of the B vitamins (except B12), folate, and vitamin E. Tomatoes are delicious in their raw form and offer a wide variety of nutrients known for their anti-inflammatory and anti-cancer properties. But did you know that cooking tomatoes enhances these properties? As with other vegetables/fruits, applying heat to tomatoes reduces vitamin C content. Despite this, research has shown that cooking a tomato significantly increases its lycopene content and total antioxidant activity, thereby boosting its positive effects on heart health and cancer prevention.17 Bottom line? Don’t stop eating raw tomatoes; they are good for your body. But consuming cooked tomato products, such spaghetti sauce and even ketchup, can offer additional health benefits.


1. Cooking vegetables can significantly decrease water-soluble vitamins, such as vitamins A and C. 

2. For some vegetables, cooking negatively impacts antioxidant activity. 

3. Destruction of water-soluble vitamins and antioxidant activity through cooking can be greatly mitigated by using minimal water and short cook times. 

4. Overall, boiling and long cooking times appear to leech more nutrients out of vegetables than other methods of cooking. 

5. Microwave cooking and/or using minimal water and short cooking times appear to best preserve nutrients that are susceptible to heat, compared to other cooking methods

6. Cooking certain vegetables, such as broccoli, spinach, and tomatoes, can increase the bioavailability of certain nutrients and antioxidant activity compared to their raw forms.

7. Cooked vegetables still provide fiber, vitamins, minerals, and antioxidants, and may be more easily digested than raw vegetables. 

8. Whether cooked or raw, adults should consume 1.5 to 2 cups of fruit and 2 to 3 cups of vegetables every day. Varying how you prepare fruits and vegetables (i.e., eating both raw and cooked vegetables) can ensure you benefit from the full range of nutrients these plant-based foods offer.


1. English LK, Ard JD, Bailey RL, et al. Evaluation of dietary patterns and all-cause mortality: a systematic review. JAMA Netw Open. 2021;4(8):e2122277. 

2. Ronco S. Raw food vs. cooked food: a nutrient analysis. Foodandhealth.communications® website.,B12%2C%20phosphorus%2C%20and%20zinc. Accessed 15 Nov 2022.

3. Lee S, Choi Y, Jeong HS, et al. Effect of different cooking methods on the content of vitamins and true retention in selected vegetables. Food Sci Biotechnol. 2018 Apr; 27(2): 333–342.

4. website. Beets, raw. Accessed 15 Nov 2022.

5. Ramos JA, Furlaneto KA, de Mendonça VZ, et al.  Influence of cooking methods on bioactive compounds in beetroot. Semina: Ciencias Agrarias. 2017;38(3):1295.

6. website. Beets, drained, boiled, cooked. Accessed 16 Nov 2022.

7. website. Broccoli, raw. Accessed 16 Nov 2022.

8. Lee S, Choi Y, Jeong HS, et al. and true retention in selected vegetables. Food Sci Biotechnol. 2018 Apr; 27(2): 333–342.

9. website. Broccoli, without salt, drained, boiled, cooked. Accessed 16 Nov 2022.

10. website. Carrots, raw. Accessed 16 Nov 2022.

11. De Castro NT, de Alencar ER, Zandonadi RP, et al. Influence of cooking method on the nutritional quality of organic and conventional brazilian vegetables: a study on sodium, potassium, and carotenoids. Foods. 2021 Aug; 10(8): 1782.

12. website. Carrots, without salt, drained, boiled, cooked. Accessed 16 Nov 2022.

13. website. Sweet potatoes, unprepared, raw. Accessed 16 Nov 2022.

14. Tang Y, Cai W, Xu B. Profiles of phenolics, carotenoids and antioxidative capacities of thermal processed white, yellow, orange and purple sweet potatoes grown in Guilin, China. Food Science and Human Wellness. 2015;4:123–132.

15. Spinach, raw. Accessed 16 Nov 2022.

16. McKillop DJ, Pentieva K, Daly D, et al. The effect of different cooking methods on folate retention in various foods that are amongst the major contributors to folate intake in the UK diet. Br J Nutr. 2002;88(6):681-688.

17. Dewanto V, Xianzhong W, Kafui K, et al. Thermal processing enhances the nutritional value of tomatoes by increasing total antioxidant activity. J Agric Food Chem. 2002 May 8;50(10):3010-3014.  

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