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什么是Antioxidants -抗氧化剂
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就alicetsm 所提出的回复，补充一些资料。
Antioxidants 不是治癌用的，不要让销售人员为了本身的利益而误导了你。
抗氧化剂就是某种成分,它能保护我们的细胞免遭一种叫做自由基（Free Radical)的伤害, 抗氧化剂能阻止自由基对我们身体细胞产生的破坏. 维他命A,C,D,E 都是有效的抗氧化剂。
什么是自由基？您就会正确理解抗氧化剂对人类健康的真正含义
自由基 :
细胞内正常的新陈代谢会利用氧气生成能量（称为氧化），自由基就是在这个过程中形成的。如果这些自由基不能迅速地被抗氧化物中和，他们甚至可以产生更不稳定的自由基，或对细胞膜、血管壁、蛋白质、脂肪乃至于细胞DNA核心产生破坏。科学和医生文献把这种破坏称为氧化压力。氧化压力几乎是所有这些慢性退化性疾病的根本原因
其他的工作，就交给我们人体的细胞吧。
市面上已有很多？那就要了解 NAZA RIA 和 TOYOTA WISH 的分别了。 |
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发表于 9-5-2008 07:59 PM
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回复 1# 事实胜于雄辩 的帖子
oi, uncle
维他命D不是antioxidant...
维他命A也不完全是...
主要的只有维他命C跟E而已...
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发表于 9-5-2008 08:18 PM
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Vit A 不能吃多。会increase risk of osteoporosis |
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楼主 |
发表于 9-5-2008 08:29 PM
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原帖由 jinreung 于 9-5-2008 07:59 PM 发表 
oi, uncle
维他命D不是antioxidant...
维他命A也不完全是...
主要的只有维他命C跟E而已...
B-胡萝卜素（维生素A原）--Beta-carotene
B胡萝卜素是类胡萝卜素家族（一组吸收蓝绿色光的光合植物色素）中最著名的一员，在机体营养状况中B-胡萝卜素起著双重作用。就像一种抗氧化剂一样，B-胡萝卜素所具有的广泛性共价双键结构使其能有效地同单氧根化合物进行反应，以吸收和分散它们对机体细胞的破坏能力。作为维生素A原，B-胡萝卜素以一种完全不同的方式向机体提供部分机体所需要的视黄醇（维生素A）。
Marcel Dekker Inc. New York NY,1996.pp 259-314
我们只是简单的慨述，不是每一个人像你这样专业。
至于D, 打字错误，抱歉。。
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楼主 |
发表于 9-5-2008 08:32 PM
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原帖由 alicetsm 于 9-5-2008 08:18 PM 发表
Vit A 不能吃多。会increase risk of osteoporosis
所以一定要选公司，看产品的成分，最好是。。。请产参考楼上。 |
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发表于 9-5-2008 08:35 PM
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原帖由 事实胜于雄辩 于 9-5-2008 20:29 发表 
B-胡萝卜素（维生素A原）--Beta-carotene
B胡萝卜素是类胡萝卜素家族（一组吸收蓝绿色光的光合植物色素）中最著名的一员，在机体营养状况中B-胡萝卜素起著双重作用。就像一种抗氧化剂一样，B-胡萝卜素所 ...
oi, uncle...
你应该懂维他命A不完全等于Beta carotene吧...
维他命A还包括retinoic acid, retinol等吧?
再说,Beta carotene被转换成active form时就失去了它的抗氧化作用...
retinol反而没有抗氧化作用,而且过量会导致中毒..
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发表于 9-5-2008 08:39 PM
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原帖由 事实胜于雄辩 于 9-5-2008 20:32 发表
所以一定要选公司，看产品的成分，最好是。。。请产参考楼上。
不管公司的事...
关不同种类的维他命A的事...
http://www.mayoclinic.com/health/vitamin-a/NS_patient-vitamina
Side Effects and Warnings Vitamin A toxicity, or hypervitaminosis A, is rare in the general population. Vitamin A toxicity can occur with excessive amounts of vitamin A taken over short or long periods of time. Consequently, toxicity can be acute or chronic. An infant with acute toxicity can develop a bulging fontalle (the soft spot on the head) and symptoms similar to a brain tumor. Adults experience less specific symptoms such as headache, dizziness, fatigue, malaise, blurry vision, bone pain and swelling, nausea, and/or vomiting. Acute vitamin A toxicity may also lead to increased intracranial pressure, pruritus or itching, and bone problems. Severe toxicity can lead to eye damage, high levels of calcium, and liver damage. Persons with liver disease and high alcohol intake may be at risk for hepatotoxicity from vitamin A supplementation. Smokers who consume alcohol and beta-carotene may be at an increased risk for lung cancer or cardiovascular disease.
Vitamin A toxicity may lead to intrahepatic cholestasis, a condition where bile cannot flow from the liver into the intestines. Treatment with ursodeoxycholic acid has been shown to greatly improve the symptoms of cholestasis. |
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发表于 9-5-2008 08:41 PM
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关于Beta carotene的:
Cancer
While diets high in fruits and vegetables rich in beta-carotene have been shown to potentially reduce the incidence of certain cancers, results from randomized controlled trials with oral supplements do not support this claim. There is some concern that beta-carotene metabolites with pharmacological activity can accumulate and potentially have cancer-causing (carcinogenic) effects. A higher, statistically significant incidence of lung cancer in male smokers who took beta-carotene supplements has been discovered. Beta-carotene/vitamin A supplements may have an adverse effect on the incidence of lung cancer and on the risk of death in smokers and asbestos exposed people or in those who ingest significant amounts of alcohol. In addition, high-dose antioxidants theoretically may interfere with the activity of some chemotherapy drugs or radiation therapy. Therefore, individuals undergoing cancer treatment should speak with their oncologist if they are taking or considering the use of high dose antioxidants. Beta-carotene in the amounts normally found in food does not appear to have this adverse effect.
http://www.nlm.nih.gov/medlinepl ... t-betacarotene.html |
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楼主 |
发表于 9-5-2008 08:54 PM
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原帖由 jinreung 于 9-5-2008 08:35 PM 发表
oi, uncle...
你应该懂维他命A不完全等于Beta carotene吧...
维他命A还包括retinoic acid, retinol等吧?
再说,Beta carotene被转换成active form时就失去了它的抗氧化作用...
retinol反而没有抗氧化作用,而且过 ...
维生素C、维生素E和B-胡萝卜素各自都能产生重要的抗氧化作用，但是，这三种营养一同服用后的协同作用更能生令人震惊的保护效果。一些流行病学研究的结果显示、维生素C、维生素E和B-胡萝卜素合并使用能明显地降低死亡於心脏病或中风的危险。维生素C、维生素E、和B-胡萝卜素在控制癌症细胞分化方面起重要的作用。这三种维生素对癌症细胞表现出强大的细胞毒（使细胞死亡）效应，甚至能够使癌细胞转变成正常细胞。
Prima Health,Rocklin CA,1995 P16
AM J Epidemiol 1991.133 766-775
Faseb J 1993,7(4):a519
Int J Vitam Nutr Res 1994,(64)J:3-14
医生，我们只是分享产品，偏偏你们要什么“医学报告”，消费者会吗？
你还要什么“报告”，短讯来向我拿，不要在这浪费版位。
我告诉你某某餐馆的curry 鱼头很好吃，偏要问我用什么curry 粉，放几多耶浆，
真的莫名其妙。
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发表于 9-5-2008 09:41 PM
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发表于 9-5-2008 09:59 PM
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回复 9# 事实胜于雄辩 的帖子
另外,关于肺癌的,有一篇提到:
For individuals at risk for lung cancer and for patients with a history of lung cancer, the use of vitamin E, retinoids, N-acetylcysteine, and aspirin is not recommended for primary, secondary, or tertiary prevention of lung cancer. Grade of recommendation, 1A
摘自:
Lung Cancer Chemoprevention ACCP Evidence-Based Clinical Practice Guidelines (2nd Edition)
Chest - Volume 132, Issue 3 (September 2007) - Copyright © 2007 The American College of Chest Physicians |
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楼主 |
发表于 9-5-2008 10:12 PM
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原帖由 jinreung 于 9-5-2008 09:59 PM 发表
另外,关于肺癌的,有一篇提到:
摘自:
Lung Cancer Chemoprevention ACCP Evidence-Based Clinical Practice Guidelines (2nd Edition)
Chest - Volume 132, Issue 3 (September 2007) - Copyright © 2007 ...
肿瘤专家和放射科专家通常都不主张病人在接受癌症治疗时使用抗氧化物质。为什么？
因为医生们担心抗氧化物质会为癌细胞建立起抗氧化防御系统而导致他们的治疗无效，因为他们的治疗原理主要就是通过产生氧化压力来破坏癌细胞。 |
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发表于 9-5-2008 10:12 PM
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Vitamins might increase risk of skin cancerThe Lancet Oncology - Volume 8, Issue 10 (October 2007) - Copyright © 2007 Elsevier
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Newsdesk
Vitamins might increase risk of skin cancer
Nayanah Siva
PII S1470-2045(07)70310-8
The incidence of all types of skin cancers is higher in women receiving antioxidant supplementation compared with men, report French researchers, led by Serge Hercberg (Centre de Recherche en Nutrition Humaine Ile-de-France, Paris, France; J Nutr 2007; 137: 2098–105).
Past studies have suggested that nutrients with antioxidant ability might prevent the harmful effects of sun exposure. Several clinical trials have tested whether antioxidant supplementation has beneficial effects on the incidence of skin cancer but no consensus has been reached. The initial aim of Hercberg and colleagues was to test whether supplementation with a combination of antioxidant vitamins and minerals could decrease the risk of skin cancers, but their research showed other surprising findings. “This is the first large primary intervention trial suggesting [differing] results (according to gender) from supplementation with antioxidants on the incidence of skin cancers, especially with a deleterious effect in women”, says Hercberg.
7876 women and 5141 men, aged 25–60 years, were randomly assigned to an oral daily capsule of antioxidants (120 mg vitamin C, 30 mg vitamin E, 6 mg beta-carotene, 100 μg selenium, and 20 mg zinc) or to placebo and were followed-up for a median of 7·5 years. There was no difference between the antioxidant and placebo groups with regard to cancer incidence (4·1% in the antioxidant group vs 4·5% in the placebo group). However, the incidence of skin cancers was higher in women in the antioxidant group than in women in the placebo group, but there was no difference in incidence in men between the two treatment groups.
Hans Fisher (State University of New Jersey, NJ, USA) hopes that this study will be followed up with animal studies on a variety of cancers, “testing the hypothesis that high levels of vitamin E may aggravate rather than lower the incidence of the cancers”.
Link between vitamins and skin cancer needs to be elucidated further
所以是不是有关联,还是有待追究... |
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发表于 9-5-2008 10:17 PM
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原帖由 事实胜于雄辩 于 9-5-2008 22:12 发表
肿瘤专家和放射科专家通常都不主张病人在接受癌症治疗时使用抗氧化物质。为什么？
因为医生们担心抗氧化物质会为癌细胞建立起抗氧化防御系统而导致他们的治疗无效，因为他们的治疗原理主要就是通过产生氧化压力 ...
你到底有没有认真地读?
里头也有讲
For individuals at risk for lung cancer and for patients with a history of lung cancer, the use of vitamin E, retinoids, N-acetylcysteine, and aspirin is not recommended for primary, secondary, or tertiary prevention of lung cancer. Grade of recommendation, 1A
注: Primary prevention是属于预防措施,secondary跟tertiary prevention是属于治疗措施
[ 本帖最后由 jinreung 于 9-5-2008 10:18 PM 编辑 ] |
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楼主 |
发表于 9-5-2008 10:31 PM
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楼主 |
发表于 9-5-2008 10:47 PM
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原帖由 jinreung 于 9-5-2008 10:12 PM 发表
所以是不是有关联,还是有待追究...
又要我重复？
Antioxidants 不是治癌用的，不要让销售人员为了本身的利益而误导了你。 |
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发表于 9-5-2008 10:58 PM
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识少少在这里扮代表 |
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发表于 9-5-2008 11:04 PM
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发表于 9-5-2008 11:10 PM
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发表于 9-5-2008 11:55 PM
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原帖由 事实胜于雄辩 于 9-5-2008 22:47 发表
又要我重复？
Antioxidants 不是治癌用的，不要让销售人员为了本身的利益而误导了你。
你要我重复多少次你才弄明白?
There was no difference between the antioxidant and placebo groups with regard to cancer incidence |
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