Carrots are rich in Beta Carotene
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β-Carotene is an organic, strongly coloured red-orange pigment abundant in plants and fruits. It is a member of the carotenes, which are terpenoids (isoprenoids), synthesized biochemically from eight isoprene units and thus having 40 carbons. Among the carotenes, β-carotene is distinguished by having beta-rings at both ends of the molecule. β-Carotene is biosynthesized from geranylgeranyl pyrophosphate. β-Carotene is the most common form of carotene in plants.
All the orange colour is beta carotene is the orange pigment found in carrots, therefore the whole of the orange carrots contains beta-carotene. One small raw carrot (100g) contains 8,353 international units of vitamin A, which includes 4,142 micrograms of beta-carotene.
Beta Carotene, along with other carotenoids, is a molecule that the body easily changes into Vitamin A. While most nutrition labels will list a recommended amount of vitamin A to include in a healthy diet, most health professionals will recommend that beta carotene be the main source of that vitamin A consumption. The reason for this is that beta carotene and other carotenoids are found mainly in fruits and vegetables which contain a host of other vitamins and minerals and are very low in fat. Vitamin A, however, if consumed in its full form, is mainly found in butter and eggs. Getting your recommenced daily allowance of vitamin A without using beta carotene would mean eating large amounts of saturated fats that would be incredibly unhealthy. Once absorbed by the small intestines, beta carotene is changed directly into Vitamin A.
Of the 600 known carotenoids, beta-carotene is the most studied and the most physiologically and nutritionally important member of the carotene family.
About 50 carotenoids have been identified in the human diet, 34 have been identified in the human serum, tissues, and breast milk. Of these, alpha-carotene, beta-carotene, and beta-cryptoxanthin are considered "essential " because they serve as precursors of vitamin A (converted to vitamin A by the body).
Beta-carotene (C40 H56) is an orange pigment found in most fruits and vegetables. It was discovered by Heinrich Wilhelm Ferdinand Wackenroder in 1831 in the roots of carrots and named the substance "carotin." Wackenroder was an analytical chemist at the Pharmaceutical Institute in Jena, Germany (www.life.illinois.edu/govindjee/CarFin 1.html).
In 1831, beta-carotene was first isolated from the roots of carrots, but it was not until the Nobel prize-winning research of Paul Karrer in the early 1930s that the structure of the substance was determined. The earliest use of synthesized beta-carotene was as a food colorant, but during the 1980s the vitamin precursors growing reputation as an antioxidant and a possible cancer-fighter resulted in its frequent inclusion in vitamin supplements. Since that time, however, conflicting findings about the benefits of taking synthesized beta-carotene have surfaced. In 1907, Richard Willstater assigned the formula C40 H56 to carotin - read more on carotenoids. Or here - Live Science
Beta-carotene belongs to a class of chemical compounds called carotenoids. Among many other positive health benefits, carotenoids act as a precursor to vitamin A, so if you know about the benefits of vitamin A, you will completely understand the importance of beta-carotene.
Basically, when you consume foods or ingest supplements containing beta-carotene, it breaks down into vitamin A in your liver.
Beta-carotene is thought to possess many positive health benefits and in particular helps prevent night blindness and other eye problems.
It also effective in skin disorders, enhances immunity, protects against toxins and cancer formations, colds, flu, and infections. It is an antioxidant and protector of the cells while slowing the aging process.
It is considered that natural Beta-Carotene aids in cancer prevention. It is important in the formation of bones and teeth. No vitamin overdose can occur with natural Beta-Carotene. It has been reported that beta carotene offers a notable measure of photoprotection to individuals with porphyria. (Beta-Carotene helps to protect the eye and vision).
Vitamin A is necessary for a large number of metabolic functions similar to other vitamins. One of the major unique functions of vitamin A is it΄s role in vision, especially dim-light vision. In third world countries where fruit and vegetables are not readily available, vitamin A deficiency is the leading cause of blindness in children. Beta carotene is a rather cheap vitamin to produce, which means this type of blindness is easily preventable.
Vitamin A produced from beta carotene is also necessary for normal cell growth and cell division. DNA replication requires the presence of vitamin A to function properly. Because of this, rapidly dividing cells often give the first signs of vitamin A deficiency. These symptoms include poor skin quality, brittle hair and nausea because of problems with the lining of the stomach. Vitamin A is also an important part of bone and teeth development. Inadequate Vitamin A during the growing years will lead to abnormal growth of the extremities.
Another important function of vitamin A includes its use by the body as an antioxidant. An antioxidant is a molecule that the body can use to block a number of harmful chemical reactions. One of these harmful reactions involves the interference of DNA replication by free radicals. Vitamin A and other antioxidants bind with the free radicals and keep them from disrupting cell division. Another very important action of antioxidants and vitamin A involve the formation of plaques by cholesterol. Once inside the bloodstream, cholesterol binds together and forms plaques which then attach to the inside of the artery wall and restrict blood flow. Antioxidants including vitamin A, keep the cholesterol from binding together, and also prevent it from attaching to the walls of the arteries
Heart disease. People whose diets are rich in beta carotene have lower risk of heart disease. Beta carotene works with vitamin E to reduce the oxidation of LDL-cholesterol, which lowers the risk of atherosclerosis and coronary heart disease.
Respiratory system problems. High intakes of beta carotene and vitamin C were found to increase lung capacity and relieve respiratory problems, as well as protecting you from breathing disorders such as asthma, bronchitis and emphysema.
Cancer. Studies show that people who eat a diet rich in carotenoids, had a much lower risk of breast, colon cancer and lung cancer. One way that carotenoids fight cancer is through their antioxidant capacity. Another way that they help is to keep your cells in proper communication, an effective preventive measure against the growth of cancer cells.
Immune system. Beta carotene helps activate your thymus gland, one of your most important sources of immune protection. The thymus gland stimulates your immune system to fight off infections and viruses, and destroy cancerous cells before they can spread.
Radiation. Combining beta carotene with vitamins E & C offers significant protect against ultraviolet radiation from the sun, as well as from chemotherapy. It's interesting to note that vitamin C and vitamin E do not offer this protection on their own. This reinforces the fact that antioxidants work more effectively as a team.
Diabetes. Studies have shown that
people with low levels in their bodies are much more likely to suffer from
impaired glucose tolerance and diabetes.
Additional beta carotene benefits include:
Like all carotenoids, beta-carotene is:
the most common form of carotene
fat soluble - not water-soluble. In a mixed diet, 3-5 grams of fat is enough to ensure its absorption. Carotenoids suspended in oil are more efficiently absorbed than those in water or food.
manufactured by plants - not animals. In plants, beta-carotene absorbs light, and energy from singlet oxygen - an unstable form of oxygen - and transfers both energies to chlorophyll for photosynthesis. It also acts as a pesticide.
present in the all-trans configuration in raw fruits and vegetables
converted to the cis- configuration during cooking. Cis- isomers are shorter in length and are less susceptible to "binding." They are more stable and are more bioavailable.
released from the food matrix by: chewing, stomach action, and digestive enzymes. The vitamin A activity of beta-carotene in foods is half that of retinol (pre-formed vitamin A). Biologic Activities of Beta-Carotene
Beta-carotene is converted to Vitamin A (retinal) in the small intestines of mammals by beta-,carotene 15,15 monooxygenase (an enzyme). In times of plenty, retinal is stored in the liver. It is synthesized into active vitamin A in times of need.
It quenches singlet oxygen. It also reacts with any radical species present in a biological system. As a powerful antioxidant, it breaks down and converts harmful products to inert substances.
It prevents the oxidation of fat by breaking down the chain-reaction.
It facilitates communication between cells by enhancing the expression of a gene that codes for connexin proteins. Connexin proteins forms pores or gap junctions in cell membranes, allowing cells to communicate through the exchange of small molecules.
It improves immune function by protecting phagocytic cells (white blood cells that protects the body by ingesting harmful bodies, bacteria, dead/dying cells); enhancing the response of T & B cells (immune response cells); by stimulating the effects of T-cell functions, macrophage, and natural killer cell capacities, and by increasing the production of interleukins. Interleukins are signalling molecules on white blood cells. They mediate communication between cells.
It helps maintain night vision. As vitamin A, beta-carotene maintains the cornea and participates in the conversion of light energy into nerve impulses at the retina. The cells of the retina contain rhodopsin, a pigment molecule. As rhodopsin absorbs light, retinal changes which triggers a nerve impulse that carries information to the brain.
It protects against sunburn by: quenching radical oxygen species and interferring with several signalling pathways that result in UV-B exposure. Significant Food Sources Sweet potatoes tubers and leaves, carrots, cantaloupes, goji berries, palm oil, spinach, chard, egg yolk, liver,pumpkins, squash, mango, turnip greens.
(References Bendich A & Olson TA "Biological Actions of Carotenoids" FASEB Journal June 1989;3(8):1927-32); http://lpi.oregonstate.edu/infocenter/phytochemicals/carotenoids/)
So what is your carotene
need? Meeting your vitamin A requirement from beta carotene is easy:
Eat a handful of baby carrots and you've done it! Six ounces of carrot juice
(made from two medium-sized carrots) supplies a whopping 28 mg. of beta
Since juicing eliminates the hard to digest fibre, nutrients are obtainable to the body in a great deal of larger quantities than if the piece of fruit or vegetable was eaten whole. For instance, since a lot of of the nutrients are in the fibre, when you eat a raw carrot, you are only able to absorb about 1% of the beta-carotene. When a carrot is juiced, eliminating the fibre, virtually 100% of the beta-carotene may be assimilated.
*RDA = Recommended Daily Amount (The RDA of Vitamin A is 800 micrograms for women and 1,000 micrograms for men.) For more information about Vitamin A click here
Tests have shown that three percent of the total beta-carotene content is released from raw carrots when consumed in raw pieces. When homogenized (pulped) 21% was released. Cooking the pulp increased the accessibility to 27%. Addition of cooking oil to the cooked pulp further increased the released amount to 39%. (European Journal of Clinical Nutrition (2002) 56, 425430- Estimation of carotenoid accessibility from carrots determined by an in vitro digestion method, Hedren et al)
The Museum page about Vitamin A is here.
Top 10 Foods highest in beta-carotene:
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