What is it?
Beta carotene is a yellow-orange carotenoid found in many fruits, as well as dark green leafy vegetables. Perhaps the best known from the family of molecules called carotenoids, beta carotenes are not destroyed in cooking. The body takes what it needs and the rest lurks somewhere underneath the fat, without causing any damage.
It is beta carotene that gives the characteristic pigment to orange foods, which include citrus fruits, sweet potatoes and also vegetables such as carrots, spinach, lettuce and tomatoes. Choose fruits and vegetables with deep rich colours for their abundance of vitamins and other beneficial substances. Your diet should include oranges, apricots, carrots, pumpkins, sweet potatoes and peaches for that extra dose of beta carotene.
Pluses all the way
A citrus fruit a day helps improve vision, fight cancer and pumps up the body’s immune system. Says Arpit Jain, consultant, internal medicine, Artemis Health Institute at Gurgaon near New Delhi: “Citrus fruits have the highest antioxidant activity among all fruits and are full of vitamins. Two to three servings of fruits every day are important for good health, and don’t forget to include citrus fruits to the list.”
Beta carotenes are very potent antioxidants, or substances that help prevent or reduce the formation of damaging chemicals, called free radicals (which could lead to heart diseases and cancer) in the body. Research suggests that because of their antioxidant actions, beta carotenes are very crucial in the body’s fight against pre-cancerous conditions affecting various parts of the body.
Doctors say beta carotenes also play a crucial role in boosting the body’s immune system, help to prevent night blindness, skin disorders, offer protection against toxins, colds, flu and other infections. In fact, some studies also stress that this antioxidant even helps slow down the ageing process. They also help in reducing blood cholesterol and are said to be effective for those with Type 2 diabetes.
Precursor of vitamin A
Beta carotenes are the best precursor (a substance from which another substance is formed) of vitamin A. This means that our body has the ability to convert this molecule into vitamin A, a fat-soluble nutrient that is crucial to maintaining vision, strengthening the immune system and keeping the skin healthy.
The interesting thing is that this conversion, in approximately 2:1 ratio, is limited by a feedback system—if the body already has enough vitamin A, the molecule starts acting as an antioxidant and protects our cells. Also, while pre-formed (pure) vitamin A in huge amounts in the body may be toxic, excess beta carotene is not harmful because it is not stored in the liver. Doctors say the only ill effect of the excess of this molecule in the body is the possibility of carotenemia, a harmless condition in which the skin acquires an orange hue.
The right mix
Beta carotene are not recognized as an essential nutrient in the same way as vitamin A. Therefore, there is no recommended intake. Says Ashutosh Shukla, head of the department of medicine, Artemis Health Institute, Gurgaon: “For people above 18, 15-180mg of beta carotene intake is recommended. Five servings of fruits and vegetables daily give you about 10mg of beta carotene.” One large carrot has about 10,600 International Units.
However, 30mg or more of beta carotene daily from supplements may cause yellowing of the skin, especially the palms of the hand and soles of the feet, joint pains, dizziness and unusual bleeding, says Dr Shukla. This condition usually disappears when excess beta carotene is removed from the diet. Adds Dr Shukla: “People who have a history of vitamin A allergy, kidney and liver disease patients, and pregnant and lactating women should also avoid taking beta carotene.”
Protection from cancer
Doctors suggest that eating fruits and vegetables daily may reduce the risk of cancer and heart diseases. For years, studies have shown a lower incidence of cancer and other chronic diseases in people who consume large amounts of fruits and vegetables. In fact, nutrition experts say it is very likely that many substances work together to provide protection and, therefore, it is best to get your beta carotene from a balanced diet. Says Dr Jain: “Beta carotenes have the capacity to prevent certain types of cancers, but they are yet to be clinically proved. There is, however, strong evidence that they do help in warding off cancers.”
Says Dr Shukla, quoting a study published in the New England Journal of Medicine: “Smokers should be more careful as excess beta carotene can make them prone to liver and oral pharyngeal cancer.”
More about citrus fruits
Orange foods also contain flavonoids and vitamin C. Some fruits such as oranges, tangerines and nectarines also have compounds called hesperetin and naringenin: these boost the cells’ ability to fight diseases. However, these may not reverse sagging skin or repair damaged knees.
Like beta carotenes, vitamin C, too, is an antioxidant, but it has an additional function: It helps the body maintain a collagen—a glue-like protein that holds our cells together. Collagen is also used to help support our joints.
Even citrus peels contain a compound called limonene which researchers think can inhibit the growth of cancer cells, at least in laboratory conditions.
Orange foods are also a good source of the potassium, a mineral crucial for maintaining a healthy blood pressure and reducing the risk of heart attacks. Vitamin C is also known as ascorbic acid: It is good for strong gums and helps avoid skin diseases like scurvy.
MORE ORANGE FACTS
* Nectarine is called a peach without the fuzz and its juice is called the “drink of the gods”
* Tangerines are a good source of vitamin C, but oranges provide about 40% more of the same vitamin
* Peaches are native to China and were once a symbol of longevity and immortality
* Remains of sweet potato have been found in caves in Peru and are believed to be more than 10,000 years old
* Dried apricots provide more than twice the amount of beta carotene found in the fresh variety
©2007/THE NEW YORK TIMES