What is beta-carotene? What are the benefits?
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What is beta-carotene? What are the benefits?
By Christian Nordqvist
Beta-carotene is a red-orange pigment found in plants and fruits, especially carrots and colorful vegetables.
The name beta-carotene comes from the Greek "beta" and Latin "carota" (carrot). It is the yellow/orange pigment that gives vegetables and fruits their rich colors. H. Wachenroder crystallized beta-carotene from carrot roots in 1831, and came up with the name "carotene".
Beta-carotene's chemical formula - C40H56 - was .
The human body converts beta-carotene into
A (retinol) - beta-carotene is a precursor of vitamin A. We need vitamin A for healthy skin and mucus membranes, our immune system, and good eye health and vision.
Beta-carotene in itself is not an essential nutrient, but vitamin A is.
Fast facts on beta-carotene
Here are some key points about beta-carotene. More detail and supporting information is in the main article.
Beta-carotene is a red/orange pigment found in many fresh fruits and vegetables
Beta-carotene is converted into vitamin A, an essential vitamin
Vitamin A is toxic at high levels
Beta-carotene is a carotenoid and an
Foods rich in vitamin A include , carrots, peas, spinach and squash
One study showed that smokers with high beta-carotene intake might have an increased risk of
Some evidence suggests that beta-carotene might slow cognitive decline
Beta-carotene supplements interact with certain drugs, including statins and mineral oil
Beta-carotene might help older people retain their lung strength as they age.
Beta-carotene from food is a safe source of vitamin A
Vitamin A can be sourced from the food we eat, through beta-carotene, for example, or in supplement form. The advantage of dietary beta-carotene is that the body only converts as much as it needs.
Excess vitamin A is toxic. Toxic vitamin A levels can occur if you consume too many supplements.
Beta-carotene is an antioxidant
The flamingo's characteristic red-orange color is caused by beta-carotene in their diet.
Beta-carotene, like all carotenoids, is an antioxidant. An antioxidant is a substance that inhibits the oxidatio it protects the body from free radicals.
Free radicals damage cells through oxidation. Eventually, the damage caused by free radicals can cause several chronic illnesses.
Several studies have shown that antioxidants through diet help people's immune systems, protect against free radicals, and lower the risk of developing
Some studies have suggested that those who consume at least four daily servings of beta-carotene rich fruits and/or vegetables have a lower risk of developing cancer or heart disease.
Which foods are rich in beta-carotene?
The following foods are rich in beta-carotene:
Chinese cabbage
Dandelion leaves
Grapefruit
Herbs and spices - chilli powder, oregano, paprika, parsley
Many margarines
Sweet potatoes.
If you follow a healthy diet rich in beta-carotene you do not need supplements. As mentioned above, supplements can lead to undesirable excesses in beta-carotene levels - this cannot occur if your source is from the food you eat.
Smokers and beta-carotene lung cancer risk
A French study involving adult females published in the Journal of the National Cancer Institute (September 2005 issue) found that smokers with high beta-carotene levels had a
and other smoking-related cancers than other smokers. They also found that non-smokers with high beta-carotene intake had a lower risk of lung cancer.
They found that the risk of lung cancer over a ten-year period was:
181.8 per 10,000 women for non-smokers with low beta-carotene intake
81.7 per 10,000 women for non-smokers with high beta-carotene intake
174 per 10,000 women for smokers with low beta-carotene intake
368.3 per 10,000 women for smokers with high beta-carotene intake.
Further research has suggested that the high intake among smokers is nearly always due to supplements, and not food intake.
Beta-carotene may slow down cognitive decline
Carrots are an excellent source of beta-carotene.
Men who have been taking beta-carotene supplements for 15 or more years are considerably
than other males, researchers from Harvard Medical School reported in Archives of Internal Medicine (November 2007 issue).
Oxidative stress is thought to be a key factor in cognitive decline, the researchers explained. Studies have shown that antioxidant supplements may help prevent the deterioration of cognition.
Their study, involving 4,052 men, compared those on beta-carotene supplements for an average of 18 years to others who were given . Over the short-term, they found no difference in cognitive decline risk between the two groups of men, but in the long-term it was clear that beta-carotene supplements made a significant difference.
The researchers emphasized that there may have been other factors which contributed to the slower decline in cognitive abilities among the men in the beta-carotene group.
Beta-carotene drug interactions
Drug interaction refers to a substance interfering in how a medication works, by either making it less effective, increasing its potency, or changing what it is supposed to do.
The following drugs may be affected by beta-carotene supplements:
Statins - the effectiveness of simvastatin (Zocor) and niacin may be decreased if the patient is taking beta-carotene with
and vitamins E and C.
Some cholesterol-lowering drugs - cholestyramine and colestipol can reduce blood levels of dietary beta-carotene by thirty to forty per cent.
Orlistat (Xenical, Alli) - this is a weight control medication. It can undermine the absorption of beta-carotene by up to 30%, resulting in lower blood beta-carotene levels. Those choosing to take a multivitamin while on orlistat should take them at least two hours before having their medication.
Mineral oil - used for the treatment of
can lower blood levels of beta-carotene.
Long-term alcohol consumption can interact with beta-carotene, raising the chances of developing liver problems.
Beta-carotene slows down lung power decline as people age
The British Medical Journal published a report in March 2006 which showed that
compensate for some of the damage to the lungs caused by oxygen free radicals.
They measured the FEV1 of 535 participants and measured their beta-carotene blood levels. FEV1 measures how much air you can breathe out in one go. They found that those with high beta-carotene levels had much slower decline in FEV1 measures.
Recent developments on supplements from MNT news
Over-the-counter dietary supplements and therapies sold to improve male sexual health may be ineffective and even unsafe, says a report published in the Journal of Sexual Medicine.
For patients with chronic , daily supplementation with vitamin D-3 may improve heart function. This is the conclusion of a new study recently presented at the American College of Cardiology 65th Annual Scientific Session & Expo in Chicago, IL.
Written by Christian Nordqvist
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Sources: Medical News Today archives, The Mayo Clinic, Wikipedia, BMJ
Please use one of the following formats to cite this article in your essay, paper or report:MLANordqvist, Christian. "What is beta-carotene? What are the benefits?." Medical News Today. MediLexicon, Intl., 26 Oct. 2016. Web.21 Aug. 2017. &/articles/252758.php&APANordqvist, C. (2016, October 26). "What is beta-carotene? What are the benefits?." Medical News Today. Retrieved from.Please note: If no author information is provided, the source is cited instead.
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2017 Healthline Media UK Ltd. All rights reserved. MNT is the registered trade mark of Healthline Media. Any medical information published on this website is not intended as a substitute for informed medical advice and you should not take any action before consulting with a healthcare professional.beta-carotene
n. 葫萝卜素
Like carrots, sweet potatoes have the antioxidant beta-carotene, which mops up damaging free radicals.
红薯与萝卜一样，含有大量的抗氧化剂，贝塔胡萝卜素。 这种抗氧化剂成分能破话自由基。
Apricots, fresh or dried, are high in beta-carotene.
新鲜或干燥的杏子都富含贝它胡萝卜素。
1.an isomer of carotene that is found in dark green and dark yellow fruits and vegetables
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扫一扫下载手机版小D啦！我们吃的那个维生素A，和抹的那个维生素A，是一个东西么 | 美丽也是技术活小组 | 果壳网 科技有意思
1078100人加入此小组
包括后面的A醇，A酸什么的百度的：维生素A的化学名为视黄醇，是最早被发现的维生素。维生素A有两种。一种是维生素A醇（retionl），是最初的维生素A形态（只存在于动物性食物中）；另一种是（carotene），在体内转变为维生素A的预成物质（provitaminA，可从植物性及性食物中摄取）嗯，就是这个问题，是不是可以买瓶安利维生素A往脸上招呼？
+ 加入我的果篮
卫生事业管理专业，geek笑点低管理员
你抹的那叫维A酸吧……没记错全名叫作反式维A酸。和维生素A根本不是一种东西……
引用 的话：你抹的那叫维A酸吧……没记错全名叫作反式维A酸。和维生素A根本不是一种东西……你看看英文名，维生素A醇（retionl），是抹脸的刷A酸之前，就是先刷它的呀
就是A醇，但不是说把药片碾碎了就好用的吧，否则我去买一瓶复合营养补充剂，那不是太美好了？VA、各种VB、VC、VE还有什么铜啊、锌啊、镁啊等等都一起糊上脸了？这配方太华丽了
卫生事业管理专业，geek笑点低管理员
引用 的话：你看看英文名，维生素A醇（retionl），是抹脸的刷A酸之前，就是先刷它的呀我们这医生没开过这玩意……
引用 的话：你看看英文名，维生素A醇（retionl），是抹脸的刷A酸之前，就是先刷它的呀A醇是A酸衍生物，刺激没那么大，一般都不是药物，也没有刷A酸之前刷A醇的说法，并且A醇不能和PH较低的护肤品一起用
引用 的话：A醇是A酸衍生物，刺激没那么大，一般都不是药物，也没有刷A酸之前刷A醇的说法，并且A醇不能和PH较低的护肤品一起用因为我是先刷的A醇，再刷的A酸，为了有个过渡现在就是想知道补剂里的维生素A跟护肤品里的A醇是不是一个东西或者说补剂里的维生素A，除了A醇，还含有胡萝卜素，护肤品只是A醇？
引用 的话：就是A醇，但不是说把药片碾碎了就好用的吧，否则我去买一瓶复合营养补充剂，那不是太美好了？VA、各种VB、VC、VE还有什么铜啊、锌啊、镁啊等等都一起糊上脸了？这配方太华丽了把药店的维生素C、E直接抹脸什么的，这种说法本来也没错
引用 的话：因为我是先刷的A醇，再刷的A酸，为了有个过渡现在就是想知道补剂里的维生素A跟护肤品里的A醇是不是一个东西或者说补剂里的维生素A，除了A醇，还含有胡萝卜素，护肤品只是A醇？是一个东西，不过胡萝卜素需要在体内转化为VA，直接涂脸上不行。
引用 的话：把药店的维生素C、E直接抹脸什么的，这种说法本来也没错那来一片善存磨碎了加点甘油涂脸上多好？买什么面霜、精华呢？
引用 的话：那来一片善存磨碎了加点甘油涂脸上多好？买什么面霜、精华呢？是啊，我就是这么想的……
引用 的话：因为我是先刷的A醇，再刷的A酸，为了有个过渡现在就是想知道补剂里的维生素A跟护肤品里的A醇是不是一个东西或者说补剂里的维生素A，除了A醇，还含有胡萝卜素，护肤品只是A醇？我只知道VA是脂溶性的，不知道和VA酸是不是一个东西，吃胡萝卜需要和动物油或者肉类一起炒VA才能被吸收。
引用 的话：我只知道VA是脂溶性的，不知道和VA酸是不是一个东西，吃胡萝卜需要和动物油或者肉类一起炒VA才能被吸收。VA是A醇吧，胡萝卜素在人体内才能转化，涂抹是没用的
引用 的话：VA是A醇吧，胡萝卜素在人体内才能转化，涂抹是没用的VA是VITAMIN A啊 维生素A，A醇是rentiol。脂溶性维生素指溶于有机溶剂而不溶于水的一类维生素。包括、、及。
引用 的话：VA是VITAMIN A啊 维生素A，A醇是rentiol。脂溶性维生素指溶于有机溶剂而不溶于水的一类维生素。包括维生素A、维生素D、维生素E及维生素K。是一个东西拉，VA就是视黄醇rentiol，就像VB5又可以叫泛醇
查个英文再维基一下就真相大白。Vitamin A is a group of unsaturated nutritional organic compounds, that includes
(维A醇、视黄醇), （视黄醛、维A醛）, （视黄酸、维甲酸、维A酸）, and several
（原维生素A 类胡萝卜素）, among which
（β胡萝卜素）is the most important.以上是维生素A的不同形式。百度百科上的分类应该是依照食物来源分类，即：食物中的维生素A主要以维生素A醇也就是视黄醇和各类胡萝卜素的形态存在。安利的维生素A主要成分好像是两种胡萝卜素，直接外用好像没啥用处，倒是吃可能作用更明显。虽然临床上有结合针刺和外涂β胡萝卜素治疗银屑病。
引用 的话：VA是VITAMIN A啊 维生素A，A醇是rentiol。脂溶性维生素指溶于有机溶剂而不溶于水的一类维生素。包括维生素A、维生素D、维生素E及维生素K。妹纸仔细看主楼维生素A包括A醇和胡萝卜素
引用 的话：查个英文再维基一下就真相大白。Vitamin A is a group of unsaturated nutritional organic compounds, that includes reti...干的漂亮！
引用 的话：查个英文再维基一下就真相大白。Vitamin A is a group of unsaturated nutritional organic compounds, that includes reti...那直接买吃的A醇？
引用 的话：那直接买吃的A醇？有卖不？视黄醇片？维A醇片？我知道有维生素A软胶囊（维生素a醋酸酯）卖。自己外用还是要小心（内服也要小心），掌握好浓度，虽然诱惑力很大，不过我不太敢试。
还真有这么多人打算这样？要真这么简单，国内化妆品公司不会有样学样吗？人家买原料可比买药片便宜多了，这么美好又简单又便宜的事怎么没人做
引用 的话：查个英文再维基一下就真相大白。Vitamin A is a group of unsaturated nutritional organic compounds, that includes reti...那这么说的话 可不可以理解为外用的最好也是用A醇
引用 的话：那这么说的话 可不可以理解为外用的最好也是用A醇不同形态的VA作用不同吧（活性形式：醛酸醇都可），虽然原维生素A 类胡萝卜素（比如β胡萝卜素α胡萝卜素）最终要转化成醇。对于皮肤来说，我也不知道这三种形式有不有哪个比哪个好的说法。
是可以 不过浓度低
我一直拿维A胶囊抹眼周
预防干纹效果还可以
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温度对β胡萝卜素光学性质的影响（本科）毕业论文（设计）.doc 46页
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本科生毕业论文（设计）中文题目
温度对β胡萝卜素光学性质的影响
Effect of temperature on optical properties of β - carotene.
要Abstract第一章
论 1第一节 类胡萝卜素的基本概念及其研究意义 1
1.1类胡萝卜素的基本概念及其特点 11.2 类胡萝卜素的研究现状 2第二节 分子光谱在类胡萝卜素研究中的作用 5
2.1 紫外-可见吸收光谱 5
2.2 激光拉曼光谱 6第二章
分子的光谱
第一节 分子的紫外-可见吸收光谱 7
1.1 辐射跃迁的选择定则和吸收强度 8
1.2 类胡萝卜素分子的紫外-可见吸收光谱 10
第二节 分子的拉曼光谱 11
2.1 散射理论 11
2.2 拉曼散射的经典解释 12
2.3 拉曼散射的量子解释 16
2.4 类胡萝卜素分子的拉曼光谱 21第三章
温度对β胡萝卜素拉曼光谱的影响 23
第一节 引言 23
第二节 实验部分 24第三节 实验结果与分析 24
3.1 温度对β胡萝卜素紫外—可见吸收光谱的影响 24
3.2 温度对β胡萝卜素拉曼光谱的影响 27结论 34致谢 35参考文献 36摘
我们知道，类胡萝卜素作为多烯类生物分子的一种，是自然界中天然存在的最丰富色素之一，而且广泛存在于涵盖人体在内的众多生物有机体内，在预防人类疾病、光合作用等方面起至关重要的作用。番茄红素、β胡萝卜素和角黄素是类胡萝卜素中最受人们关注和研究的三种类胡萝卜素。其中，β胡萝卜素在生物光合作用中有采集、转移光能等功能；番茄红素有着预防癌症和人类老化的功能，更是物理学、化学和生物学研究的热点之一。它们都是具有共轭双键结构的多烯类生物分子，是研究光学非线性、共振拉曼光谱等分子结构的非常理想样品，也是制造一些特殊功能光电器件的重要材料。我们对其进行研究，不仅有理论价值，更有现实实用价值以及广阔的应用前景。本论文采用设计物理模型以及计算机模拟结合光谱实验等方法，从多角度多方面对溶液中的类胡萝卜素（多烯类线形生物分子）光谱特性进行了研究。广泛涉及到了计算化学、分子光谱学、溶液化学等生物、物理和化学多个学科。更值得一说的是，我们引进了一个重要的物理参量—拉曼散射截面用来研究拉曼光谱。这是因为拉曼散射截面作为一个重要的参量在拉曼光谱的研究和应用中发挥着不可替代的作用。同拉曼频移和线宽表现了分子的微观特性一样，拉曼散射截面也表现了某一特定分子的光散射特性，并且能直接反映分子极化率的大小及其变化。散射截面大小不仅与散射分子的结构、激发光的频率有关，还和被散射分子所处的环境条件有关。我们测量了全反式β胡萝卜素在二甲基亚砜中81—25 ?C 温度范围的紫外—可见吸收和拉曼光谱。从不同温度下类胡萝卜素的结构有序变化出发，进而得到其结构有序对π电子离域和拉曼散射截面等光学性质的影响。为人们进一步对类胡萝卜素的结构与性质的探究提供了一定的参考资料。 关键词
类胡萝卜素
β胡萝卜素
紫外-可见光谱
拉曼光谱AbstractWe know, carotenoids as a polyene biological molecules, is a natural existence in nature, the most abundant pigment, and widely exists in human body, covering many biological organisms, plays a vital role in the prevention of human diseases, such as photosynthesis. Lycopene, beta-carotene and canthaxanthin is of concern and study the elements in three kinds of carotenoids carotenoids. Among them, beta carotene is collecting, transferring light energy functi lycopene protect against cancer and human aging, is one of the hot research in physics, chemistr
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