Energy value (calories per serving): Low
Saturated fat: Low Cholesterol: None Carbohydrates: High Fiber: High
Major vitamin contribution: Vitamin A
Major mineral contribution: Potassium
About the Nutrients in This Food
Carrots are high-fiber food, roots whose crispness comes from cell walls stiffened with the insoluble dietary fibers cellulose and lignin. Carrots also contain soluble pectins, plus appreciable amounts of sugar (mostly sucrose) and a little starch. They are an extraordinary source of vitamin A derived from deep yellow carotenoids (including beta-carotene).
One raw carrot, about seven inches long, has two grams of dietary fiber and 20,250 IU vitamin A (nine times the R DA for a woman, seven times the R DA for a man).
The Most Nutritious Way to Serve This Food
Cooked, so that the cellulose- and hemicellulose-stiffened cell walls of the carrot have partially dissolved and the nutrients inside are more readily available.
Diets That May Restrict or Exclude This Food
Disaccharide-intolerance diet (for people who are sucrase- and /or invertase-deficient)
Low-sodium diet (fresh and canned carrots)
Buying This Food
Look for: Firm, bright orange yellow carrots with fresh, crisp green tops.
Avoid: Wilted or shriveled carrots, pale carrots, or carrots with brown spots on the skin.
Storing This Food
Trim off the green tops before you store carrots. The leaf y tops will wilt and rot long before the sturdy root.
Keep carrots cool. They will actually gain vitamin A during their first five months in storage. Protected from heat and light, they can hold to their vitamins at least another two and a half months.
Store carrots in perforated plastic bags or containers. Circulating air prevents the for- mation of the terpenoids that make the carrots taste bitter. Do not store carrots near apples or other fruits that manufacture ethylene gas as they continue to ripen; this gas encourages the development of terpenoids.
Store peeled carrots in ice water in the refrigerator to keep them crisp for as long as 48 hours.
Preparing This Food
Scrape the carrots. Ver y young, tender carrots can be cleaned by scrubbing with a veg- etable brush.
Soak carrots that are slightly limp in ice water to firm them up. Don’t discard slightly wilted intact carrots; use them in soups or stews where texture doesn’t matter.
What Happens When You Cook This Food
Since carotenes do not dissolve in water and are not affected by the normal heat of cooking, carrots stay yellow and retain their vitamin A when you heat them. But cooking will dissolve some of the hemicellulose in the carrot’s stiff cell walls, changing the vegetable’s texture and making it easier for digestive juices to penetrate the cells and reach the nutrients inside.
How Other Kinds of Processing Affect This Food
Freezing. The characteristic crunchy texture of fresh carrots depends on the integrity of its cellulose- and hemicellulose-stiffened cell walls. Freezing cooked carrots creates ice crystals that rupture these membranes so that the carrots usually seem mushy when defrosted. If possible, remove the carrots before freezing a soup or stew and add fresh or canned carrots when you defrost the dish.
Medical Uses and/or Benefits
A reduced risk of some kinds of cancer. According to the American Cancer Society, carrots and other foods rich in beta-carotene, a deep yellow pigment that your body converts to a form of vitamin A, may lower the risk of cancers of the larynx, esophagus and lungs. There is no such benefit from beta-carotene supplements; indeed, one controversial study actually showed a higher rate of lung cancer among smokers taking the supplement.
Protection against vitamin A-deficiency blindness. In the body, the vitamin A from carrots becomes 11-cis retinol, the essential element in rhodopsin, a protein found in the rods (the cells inside your eyes that let you see in dim light). R hodopsin absorbs light, triggering the chain of chemical reactions known as vision. One raw carrot a day provides more than enough vitamin A to maintain vision in a normal healthy adult.
Adverse Effects Associated with This Food
Oddly pigmented skin. The carotenoids in carrots are fat-soluble. If you eat large amounts of carrots day after day, these carotenoids will be stored in your fatty tissues, including the fat just under your skin, and eventually your skin will look yellow. If you eat large amounts of carrots and large amounts of tomatoes (which contain the red pigment lycopene), your skin may be tinted orange. This effect has been seen in people who ate two cups of carrots and two tomatoes a day for several months; when the excessive amounts of these vegetables were eliminated from the diet, skin color returned to normal.
False-positive test for occult blood in the stool. The active ingredient in the guaiac slide test for hidden blood in feces is alphaguaiaconic acid, a chemical that turns blue in the presence of blood. Carrots contain peroxidase, a natural chemical that also turns alphaguaiaconic acid blue and may produce a positive test in people who do not actually have blood in the stool.