Do cooked vegetables lose their nutrition?
Do you have to eat them raw?
Because I've heard that only frozen or fried vegetables lose their nutrition.
- friendofchipLv 79 years agoFavorite Answer
Cooked veg loses some of the nutrition- vitamins tend to dissolve with heat and leak into the water.
Steaming them helps- you don't lose as much.
Raw veg contains the most vitamin content.
Frozen veg are flash cooked- blanched in boiling water to dissolve the starch on the outside, so they're not raw as you'd think.
Fried veg- well if it's quickly fried in a wok, then they don't really lose as much as when you boil them for half an hour.
The longer time they spend being heated- the worse off they'll be.
But it's kind of bad science- all vegetables have a lot of vitamins, minerals and fibre, even IF they're cooked to a mushy pulp.
- JewelLv 79 years ago
The answer is...it depends. It depnds on the vegetable, and how its cooked.
First of all, frozen vegetable lose almost none of their nutrition.
Vegetables cooked in water can lose some of their water-soluble vitamins, such as the B and C complexes. But if they are cooked briefly, in as little water as possible, they don't lose too many. Also, you can save the water in which you cooked the veggies, and add it to soup stock.
Fried vegetables don't lose vitamins, but they do tend to pick up unappetizing amounts of fat, especially if they are breaded and deep-fried. Sauteing in a bit of evoo is ok; immersing them in hot shortening is less so.
Raw veggies may be ideal for nutrition, but there are many veggies which need to be cooked to be really palatable. Many greens are bitter until they've been cooked, and other veggies actually can't be properly digested until their structure has been altered by the process of cooking.
- Anonymous9 years ago
It depends how long you cook them for, but there is always nutritional loss when cooking veggies. Raw vegetables taste great so try to avoid cooking them whenever you can to get their full nutritional benefits.
- queenjeanarleneLv 79 years ago
Some do and some don't. Those who have water soluble vitamins, like citrus some leafy greens, will lose a lot of their vitamins in the cooking liquid. However today we can microwave, roast, pan fry, there are a lot of ways to cook veggies without giving the slippery little things from getting away.Source(s): Been vegetarian,recently backslid. Still cook as if I were.
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- Anonymous9 years ago
Sweetroll, I eat raw potatoes all the time haha I eat them like apples.
Also, depending on how long you cook them they do lose them to some extent, but carrots are actually at their healthiest when they are 20-40% cooked.Source(s): Vegetarian
- sweetrollLv 79 years ago
To an extent, especially if they get overcooked.
Raw is fine if the vegetable can be eaten that way. You can't eat an artichoke raw or a potato.
Most common vegetables steam well and if you want, you can use the steaming water in a soup or broth.
- CarlLv 43 years ago
It can a vegetable when you buy it and a fruit when you eat it.
- BohemianLv 59 years ago
I always steam veg, to keep in as many nutrients as I can. I think they taste better that way too.
- JohnnyLv 59 years ago
Cooking is crucial to our diets. It helps us digest food without expending huge amounts of energy. It softens food, such as cellulose fiber and raw meat, that our small teeth, weak jaws and digestive systems aren't equipped to handle. And while we might hear from raw foodists that cooking kills vitamins and minerals in food (while also denaturing enzymes that aid digestion), it turns out raw vegetables are not always healthier.
A study published in The British Journal of Nutrition last year found that a group of 198 subjects who followed a strict raw food diet had normal levels of vitamin A and relatively high levels of beta-carotene (an antioxidant found in dark green and yellow fruits and vegetables), but low levels of the antioxidant lycopene.
Lycopene is a red pigment found predominantly in tomatoes and other rosy fruits such as watermelon, pink guava, red bell pepper and papaya. Several studies conducted in recent years (at Harvard Medical School, among others) have linked high intake of lycopene with a lower risk of cancer and heart attacks. Rui Hai Liu, an associate professor of food science at Cornell University who has researched lycopene, says that it may be an even more potent antioxidant than vitamin C.
One 2002 study he did (published in the Journal of Agriculture and Food Chemistry) found that cooking actually boosts the amount of lycopene in tomatoes. He tells ScientificAmerican.com that the level of one type of lycopene, cis-lycopene, in tomatoes rose 35 percent after he cooked them for 30 minutes at 190.4 degrees Fahrenheit (88 degrees Celsius). The reason, he says: the heat breaks down the plants' thick cell walls and aids the body's uptake of some nutrients that are bound to those cell walls.
Cooked carrots, spinach, mushrooms, asparagus, cabbage, peppers and many other vegetables also supply more antioxidants, such as carotenoids and ferulic acid, to the body than they do when raw, Liu says. At least, that is, if they're boiled or steamed. A January 2008 report in the Journal of Agriculture and Food Chemistry said that boiling and steaming better preserves antioxidants, particularly carotenoid, in carrots, zucchini and broccoli, than frying, though boiling was deemed the best. The researchers studied the impact of the various cooking techniques on compounds such as carotenoids, ascorbic acid and polyphenols.
Deep fried foods are notorious sources of free radicals, caused by oil being continuously oxidized when it is heated at high temperatures. These radicals, which are highly reactive because they have at least one unpaired electron, can injure cells in the body. The antioxidants in the oil and the vegetables get used up during frying in stabilizing the cycle of oxidation.
Another study published in the Journal of Agricultural and Food Chemistry in 2002 showed that cooking carrots increases their level of beta-carotene. Beta-carotene belongs to a group of antioxidant substances called carotenoids, which give fruits and vegetables their red, yellow, and orange colorings. The body converts beta-carotene into vitamin A, which plays an important role in vision, reproduction, bone growth and regulating the immune system.
The downside of cooking veggies, Liu says: it can destroy the vitamin C in them. He found that vitamin C levels declined by 10 percent in tomatoes cooked for two minutes—and 29 percent in tomatoes that were cooked for half an hour at 190.4 degrees F (88 degrees C). The reason is that Vitamin C, which is highly unstable, is easily degraded through oxidation, exposure to heat (it can increase the rate at which vitamin C reacts with oxygen in the air) and through cooking in water (it dissolves in water).
Liu notes, however, that the trade-off may be worth it since vitamin C is prevalent in far more fruits and vegetables than is lycopene. Among them: broccoli, oranges, cauliflower, kale and carrots. Besides, cooked vegetables retain some of their vitamin C content.
That said, research shows that some veggies, including broccoli, are healthier raw rather than cooked. According to a study in the Journal of Agricultural and Food Chemistry in November 2007, heat damages the enzyme myrosinase, which breaks down glucosinates (compounds derived from glucose and an amino acid) in broccoli into a compound known as sulforaphane.
Research published in the journal Carcinogenesis in December 2008 found that sulforaphane might block the proliferation of and kill precancerous cells. A 2002 study in The Proceedings of the National Academy of Sciences also found that sulforaphane may help fight the bacterium Helicobacter pylori, which causes ulcers and increases a person's risk of stomach cancer.Source(s): On the other hand, indole, an organic compound, is formed when certain plants, particularly cruciferous vegetables such as broccoli, cauliflower and cabbage, are cooked. According to research in The Journal of Nutrition in 2001, indole helps kill precancerous cells before they turn malignant. And while boiling carrots was found to increase carotenoid levels, another study found that it leads to a total loss of polyphenols, a group of chemicals found in raw carrots. Specific polyphenols have been shown to have antioxidant properties and to reduce the risk of cardiovascular disease and cancer, according to a 2005 report in The American Journal of Clinical Nutrition. http://www.scientificamerican.com/article.cfm?id=r...