Do you eat your carrots cooked or raw? Roast them, we say. While experts often recommend raw veggies, some vegetables are actually healthier when cooked. True, cooking can destroy water-soluble vitamins like B and C,1 and depending on the method, minerals like calcium, potassium, magnesium, iron, zinc, and phosphorus can also decline by a whopping 70%.2
Whether eating a vegetable cooked rather than raw is healthier depends on the veggie and the way you are cooking it. Deep frying has no benefit.
But this is just half the story. Cooking, light heat, or steam breaks down food into an easy-to-absorb form and releases the nutrients. It might even increase the nutrient content per portion. Cooking also helps transform potentially harmful chemicals in some vegetables into harmless ones. But it all depends on the veggie and the method of cooking. These 7 cooked vegetables are better than raw.
1. Carrots: Steamed Or Roasted
Carrots are known for their high beta-carotene content. Beta-carotene is a natural antioxidant that transforms into vitamin A within our body. But it’s not absorbed all that well when you eat the carrot raw. It needs a bit of fat for better absorption.3 So sauteing them in very little olive oil or coconut oil can help your cause.
Cooking carrots makes it easy for you to absorb more of its healthy antioxidant called beta-carotene.
Cooking carrots also breaks down the cell wall and increases absorption of its other nutrients. According to one study, the bioavailability of beta-carotene can significantly increase when the food source is heated or treated.4 So if you are eating the vegetable to increase your vitamin A intake, you may want to gently steam or roast it first. It is a wonderful (and tasty!) way to promote healthy eyes, strong bones, healthy teeth, and radiant skin.5
2. Spinach: Steamed
Spinach holds much goodness in its dark green leaves. When you cook this veggie, it wilts and shrinks considerably. This means that 1 cup of cooked spinach will technically hold more spinach (and nutrients) than 1 cup raw. But spinach also contains oxalic acid, which hinders the absorption of certain minerals like calcium and iron in your body and may even form kidney stones. There is an easy fix for this.
Steam the spinach to make it easily digestible and remove some of its oxalic acid, which can be tough on a sensitive stomach.
You lose 5–53% of the oxalic acid when you steam the spinach and 30–87% when you boil it.6 However, while the folate levels of spinach do not drop after steaming or cooking in the microwave, folate leaches out when you boil the leaves.7 Unless you have a very sensitive stomach and are prone to forming kidney stones, stick to steaming the good leaf.
3. Asparagus: Steamed
Cook asparagus by steaming, blanching, or even baking to release its vitamins and antioxidants.
The fibrous spear-headed asparagus is another vegetable that benefits from cooking. The process breaks down the fiber, making it easier to digest and absorb nutrients like vitamins A, B, C, E, and K. One study determined that it actually increases the antioxidant activity of the vegetable. Researchers noted that cooking increased absorption of vital nutrients including beta-carotene, quercetin, zeaxanthin, lutein, phenols, and rutin.8 Steam or blanch your asparagus and serve it with a healthy sauce or toss it into a salad with a light olive oil and lemon juice dressing. Or bake it into a casserole.
4. Red Peppers: Roasted
Roast or fry red peppers to keep their antioxidant levels intact.
Red peppers are an amazing source of carotenoids. And, as with carrots, cooking or processing can enhance the bioavailability of those carotenoids.9 Experts have also reported that dry heat methods can help with retention of antioxidants. Your best bet? Opt for roasting and frying instead of boiling and steaming.10 However, pay attention to cooking time and temperature. Overdoing these can destroy antioxidants that may be heat sensitive.
5. Tomatoes: Cooked With Olive Oil
Do you know that lycopene, the pigment that gives tomatoes their red, is a great help to your health? Lycopene has both anti-inflammatory and antioxidant properties, making it a valuable diet component for treating nerve-wasting diseases, cardiovascular problems, and even cancer.11
Lycopene becomes more available to your body after cooking.12 No wonder then that researchers observed that people on a long-term raw-food diet had normal levels of most nutrients – except lycopene.13
You can best absorb the antioxidant lycopene in tomatoes by pureeing or stir-frying them in olive oil.
6. Broccoli: Steamed
Choosing the right method of preparing broccoli is slightly tricky. Broccoli has a component called glucosinate which releases anticancer chemicals called sulforaphane and indoles. An enzyme in broccoli, myrosinase, makes this breakdown possible – simply chopping the broccoli can make the myrosinase break down glucosinate. But heat makes myrosinase inactive.16
If you have hypothyroidism, don’t eat your broccoli raw. Steam it to preserve the nutrients and leach out some of the thyroid-disrupting component.
So if you want protection against cancer, it would seem that eating broccoli raw is the best option, because even though your gut bacteria can break glucosinate down, it’s not as effective. But glucosinate is also a goitrogen that can interfere with your thyroid hormones and affect your metabolism.
So to retain a healthy amount of glucosinates and not affect your health, chop the broccoli well and steam it. Avoid microwaving or boiling, both of which bring the glucosinate down.17
7. Mushrooms: Cooked
Mushrooms aren’t a vegetable, strictly speaking. But these fungi form a major part of a vegetarian or vegan diet and are often considered a meat substitute. They are a mixed bag, however. After cooking, vitamin D and most B vitamins decline. Meanwhile, the same process increases the antioxidant vitamin C, which is a rather rare thing to happen because in most cases, heat makes vitamin C oxidize rapidly. In one study, the antioxidant activity of the popular shiitake mushroom increased significantly after it was heated.18 Cooking the mushrooms also brings down their calories and increases the fiber content, calcium, and iron.
Raw mushrooms are tough to digest. Cook them to also increase the amount of vitamin C and make other nutrients more available to your body.
One potent argument against eating raw mushrooms is that they are difficult to digest because of their tough cell walls made of chitin. So the nutrients aren’t all available anyway. Cooking breaks down the chitin and helps release nutrients.19 So you can bake them or cook them in a broth of your choice. But make sure you eat the right mushrooms.
|↑1||Food processing and nutrition. Better Health Channel, Victoria State Government.|
|↑2||Kimura, Mieko, and Yoshinori ITOKAWA. “Cooking losses of minerals in foods and its nutritional significance.” Journal of nutritional science and vitaminology 36, no. 4-SupplementI (1990): S25-S33.|
|↑3||Ribaya-Mercado, Judy D., Cherry C. Maramag, Lorena W. Tengco, Gregory G. Dolnikowski, Jeffrey B. Blumberg, and Florentino S. Solon. “Carotene-rich plant foods ingested with minimal dietary fat enhance the total-body vitamin A pool size in Filipino schoolchildren as assessed by stable-isotope-dilution methodology.” The American journal of clinical nutrition 85, no. 4 (2007): 1041-1049.|
|↑4||Livny, Orly, Ram Reifen, Itzhak Levy, Zecharia Madar, Richard Faulks, Sue Southon, and Betty Schwartz. “ß-carotene bioavailability from differently processed carrot meals in human ileostomy volunteers.” European journal of nutrition 42, no. 6 (2003): 338-345.|
|↑5||Vitamin A. University of Maryland Medical Center.|
|↑6||Chai, Weiwen, and Michael Liebman. “Effect of different cooking methods on vegetable oxalate content.” Journal of agricultural and food chemistry 53, no. 8 (2005): 3027-3030.|
|↑7||Delchier, Nicolas, Christiane Ringling, Jean-François Maingonnat, Michael Rychlik, and Catherine MGC Renard. “Mechanisms of folate losses during processing: diffusion vs. heat degradation.” Food chemistry 157 (2014): 439-447.|
|↑8||Fanasca, Simone, Youssef Rouphael, Eugenia Venneria, Elena Azzini, Alessandra Durazzo, and Giuseppe Maiani. “Antioxidant properties of raw and cooked spears of green asparagus cultivars.” International journal of food science & technology 44, no. 5 (2009): 1017-1023.|
|↑9||van het Hof, Karin H., Clive E. West, Jan A. Weststrate, and Joseph GAJ Hautvast. “Dietary factors that affect the bioavailability of carotenoids.” The Journal of nutrition 130, no. 3 (2000): 503-506.|
|↑10||Hwang, In Guk, Young Jee Shin, Seongeung Lee, Junsoo Lee, and Seon Mi Yoo. “Effects of different cooking methods on the antioxidant properties of red pepper (Capsicum annuum L.).” Preventive nutrition and food science 17, no. 4 (2012): 286.|
|↑11||Cruz, Bojórquez RM, Gallego J. González, and Collado P. Sánchez. “[Functional properties and health benefits of lycopene].” Nutricion hospitalaria 28, no. 1 (2012): 6-15.|
|↑12||Fielding, Jeanette M., Kevin G. Rowley, Pauline Cooper, and Kerin O’Dea. “Increases in plasma lycopene concentration after consumption of tomatoes cooked with olive oil.” Asia Pacific journal of clinical nutrition 14, no. 2 (2005): 131.|
|↑13||Garcia, Ada L., Corinna Koebnick, Peter C. Dagnelie, Carola Strassner, Ibrahim Elmadfa, Norbert Katz, Claus Leitzmann, and Ingrid Hoffmann. “Long-term strict raw food diet is associated with favourable plasma β-carotene and low plasma lycopene concentrations in Germans.” British journal of nutrition 99, no. 06 (2008): 1293-1300.|
|↑14||Rao, A. V., Zeeshan Waseem, and Sanjiv Agarwal. “Lycopene content of tomatoes and tomato products and their contribution to dietary lycopene.” Food Research International 31, no. 10 (1998): 737-741.|
|↑15||Fielding, Jeanette M., Kevin G. Rowley, Pauline Cooper, and Kerin O’Dea. “Increases in plasma lycopene concentration after consumption of tomatoes cooked with olive oil.” Asia Pacific journal of clinical nutrition 14, no. 2 (2005): 131.|
|↑16||Conaway, C. Clifford, Serkadis M. Getahun, Leonard L. Liebes, Donald J. Pusateri, Debra KW Topham, María Botero-Omary, and Fung-Lung Chung. “Disposition of glucosinolates and sulforaphane in humans after ingestion of steamed and fresh broccoli.” Nutrition and cancer 38, no. 2 (2000): 168-178.|
|↑17||Barba, Francisco J., Nooshin Nikmaram, Shahin Roohinejad, Anissa Khelfa, Zhenzhou Zhu, and Mohamed Koubaa. “Bioavailability of glucosinolates and their breakdown products: Impact of processing.” Frontiers in nutrition 3 (2016).|
|↑18||Choi, Y., S. M. Lee, J. Chun, H. B. Lee, and J. Lee. “Influence of heat treatment on the antioxidant activities and polyphenolic compounds of Shiitake (Lentinus edodes) mushroom.” Food Chemistry 99, no. 2 (2006): 381-387.|
|↑19||Chemical analysis of mushrooms shows their nutritional benefits. University of Illinois Urbana-Champaign.|