The Functions of Beta Carotene

The Functions of Beta CaroteneUnlike supplements, foods rich in beta-carotene seat no lung crabby person seek. Synthetic beta-carotene supplements abide been found to increase the risk of both colorectal and lung cancer in foragers, especially those who as well plight alcohol. A study published by an international team in the January 2004 issue of Cancer Epidemiology Biomarkers and Prevention indicates that beta-carotene consumed as part of whole foods has no much(prenominal) negatively charged effects. This study, which pooled data from seven large cohort studies running between 7 and 16 years and involving a subject population of 399,765 participants in labor union the States and Europe, found that beta-carotene from foods was non associated with some(prenominal) increased risk of lung cancer among current smokers or non-smokers. Other carotenoids in foods (lutein, zeaxanthin and lycopene) were similarly found to have no connectedness with lung cancer risk. (February 26, 2004)Food sources of beta-carotene include sweet potatoes, carrots, kale, spinach, white turnip greens, winter squash, collard greens, cilantro and fresh thyme. To maximize the avail strength of the carotenoids in the foods listed above, the foods should be eaten raw or peeved lightly.For serving size for specific foods, see Nutrient Rating Chart below at the bottom of this page.Content (Jump to)DescriptionFunctionDeficiency Symptoms toxicity SymptomsCooking, storage and processingFactors that affect functionDrug-nutrient interactionNutrient interactionHealth chassissSupplementsFood SourcesRecommendationsDescriptionWhat is beta-carotene?Beta-carotene is probably the most well known of the carotenoids, a phytonutrients family that represents of the integrity most widespread groups of naturally occurring pigments. It is one of the most abundant carotenoids in the North American diet as well as one of approximately 50 carotenoids known as provitamin Acompounds, able to be conve rted in the body into retinol, an busy form of vitamin A.While beta-carotene produces colors in the orange tree and yellow range, beta-carotene rich foods whitethorn be otherwise colors besides from these two. That is because other phytonutrients pigments blend together with the beta-carotene to give the plant food its unique penetrate that, in addition to orange or yellow, could be other colors including pink, red or white.How it FunctionsWhat argon the functions of beta-carotene?Preventing Vitamin A DeficiencyUntil late in the twentieth Century, the functions of carotenoids, including beta-carotene, were discussed only in terms of their potential vitamin A activity. Beta-carotene is one of approximately 50 carotenoids of the known 600, that are called provitamin A compounds because the body can convert them into retinol, an active form of vitamin A.As a result, foods that contain beta-carotene can help prevent vitamin A deficiency. In addition to alpha-carotene and beta-cryptox anthin, beta-carotene is among the most commonly consumed provitamin A carotenoids in the North American diet.Antioxidant Immune-Enhancing ActivityIn recent years, carotenoids including beta-carotene have received a tremendous amount of attention as potential anti-cancer and anti-aging compounds. Beta-carotene is a powerful antioxidant, protect the cells of the body from revile caused by free radicals. It is also one of the carotenoids believed to enhance the function of the immune system.Promoting Proper Cell CommunicationIn addition to their antioxidant and immune-enhancing activity, carotenoids including beta-carotene have shown the ability to stimulate cell to cell communication. Researchers now believe that poor communication between cells may be one of the causes of the overgrowth of cells, a condition which eventually leads to cancer. By promoting proper communication between cells, carotenoids may play a role in cancer prevention.Supporting Reproductive HealthIt is also be lieved that beta-carotene may participate in female reproduction. Although its exact function in female reproduction has not yet been identified, it is known that the corpus luteum has the highest concentration of beta-carotene of any organ in the body, suggesting that this nutrient plays an important role in reproductive processes.Deficiency SymptomsWhat are deficiency symptoms for beta-carotene?A low dietary intake of carotenoids such as beta-carotene is not known to directly cause any diseases or wellness conditions, at least in the short term. However, if your intake of vitamin A is also low, a dietary deficiency of beta-carotene and/or other provitamin A carotenoids can cause the symptoms associated with vitamin A deficiency.In addition, long-term inadequate intake of carotenoids is associated with degenerative disease, including flavour disease and various cancers. One important mechanism for this carotenoid-disease relationship appears to be free radicals. Research indicate s that diets low in beta-carotene and carotenoids can increase the bodys susceptibility to damage from free radicals. As a result, over the long term, beta-carotene deficient diets may increase tissue damage from free radical activity, and increase risk of chronic diseases like heart disease and cancers.Toxicity SymptomsWhat are toxicity symptoms for beta-carotene?A tell-tale sign of excessive consumption of beta-carotene is a yellowish discoloration of the skin, most lots occurring in the palms of the hands and soles of the feet. This condition is called carotenodermia, and is reversible and harmless.High intake of carotenoid-containing foods or supplements is not associated with any toxic side effects. As a result, the Institute of medicinal drug at the National Academy of Sciences did not establish a Tolerable Upper Intake Level (UL) for carotenoids when it reviewed these compounds in 2000.However, the results of two research studies indicate that those who smoke heavily and dr ink alcohol regularly, may increase their chance of developing lung cancer and/or heart disease if they take beta-carotene supplements in amounts greater than 20-30 milligrams per day. jar of Cooking, Storage and ProcessingHow do cooking, storage, or processing affect beta-carotene?In certain cases, cooking can improve the availability of carotenoids in foods. Lightly muggy carrots and spinach improves your bodys ability to absorb carotenoids in these foods.It is important to note, however, that in most cases, prolonged cooking of vegetables decreases the availability of carotenoids by changing the shape of the carotenoid from its natural trans-configuration to a cis-configuration. For example, fresh carrots contain 100% all-trans beta-carotene, while canned carrots contain only 73% all-trans beta-carotene.Factors that Affect FunctionWhat factors might contribute to a deficiency of beta-carotene?Carotenoids are fat-soluble substances, and as such require the presence of dietary fat for proper absorption through the digestive tract. Consequently, your carotenoid status may be impaired by a diet that is extremely low in fat or if you have a medical condition that causes a reduction in the ability to absorb dietary fat such as pancreatic enzyme deficiency, Crohns disease, celiac sprue, cystic fibrosis, surgical removal of part or all of the stomach, gall vesica disease, and liver disease.Due to low consumption of fruits and vegetables, many adolescents and young adults do not take in enough beta-carotene. In addition, if you smoke cigarettes and/or drink alcohol, you may have lower than normal blood levels of beta-carotene. Statistically speaking, smokers and drinkers eat fewer foods that contain carotenoids such as beta-carotene. Also, researchers suspect that cigarette smoke destroys carotenoids. However, if you do smoke or drink, use carotenoid supplements with caution (see Toxicity section).Drug-Nutrient InteractionsWhat medications affect beta-carotene?The cholesterol-lowering medications referred to as bile acid sequestrants (Cholestyramine, Colestipol, and Colestid) lower blood levels of carotenoids. In addition, margarines enriched with plant sterols such as Benecol and Take Control, may decrease the absorption of carotenoids. Olestra, a fat substitute added to snack foods, may also decrease the absorption of carotenoids.Nutrient InteractionsHow do other nutrients interact with beta-carotene?Beta-carotene supplements reduce blood levels of lutein while they may also increase blood levels of beta-cryptoxanthin.Supplementing your diet with pectin may decrease the absorption of carotenoids.Health ConditionsCarotenoids may play a role in the prevention of the following health conditionsAcquired Immunodeficiency Syndrome (AIDS)Age-related macular degenerationAngina pectorisAsthmaCataractsCervical cancerCervical dysplasiaChlamydial contagious diseaseHeart diseaseLaryngeal cancer (cancer of the larynx)Lung cancerMale and female infertil ityOsteoarthritisPhotosensitivityPneumoniaProstate cancerRheumatoid arthritisSkin cancerVaginal candidiasisForm in Dietary SupplementsWhat forms of beta-carotene are found in dietary supplements?In dietary supplements, beta-carotene is available as synthetic all-trans beta-carotene, beta- and alpha-carotene from the alga Dunaliella, and mixed carotenes from palm oil.It is important to note, however, that, due to the inconsistent results from research studies aimed at evaluating the health benefits of beta-carotene supplements, the National Academy of Sciences cautions against taking high dose carotenoid supplements, except as a method for preventing vitamin A deficiency.Food SourcesWhat foods provide beta-carotene?Beta-carotene can be found in concentrated amounts in a variety of foods including sweet potatoes, carrots, kale, spinach, turnip greens, winter squash, collard greens, cilantro, fresh thyme, cantaloupe, romaine lettuce and broccoli.Food Source Analysis not Available for t his NutrientPublic Health RecommendationsWhat are current public health recommendations for beta-carotene and carotenoids?To date, no recommended dietary intake levels have been established for carotenoids. In an effort to set such recommendations, the Institute of Medicine at the National Academy of Sciences reviewed the be scientific research on carotenoids in 2000.Despite the large body of population-based research that links high consumption of foods containing beta-carotene and other carotenoids with a reduced risk of several chronic diseases, the Institute of Medicine concluded that this evidence was not strong enough to support a required carotenoid intake level because it is not yet known if the health benefits associated with carotenoid-containing foods are due to the carotenoids or to some other substance in the food.However, the National Academy of Sciences supports the recommendations of various health agencies, which gain ground individuals to consume five or more ser vings of fruits and vegetable every day. This level of intake of fruits and vegetables provides approximately three to six milligrams of beta-carotene.