Das Ende der Vitamin C Legende

[rantanplan]

Und folgendes sollte man vielleicht auch in Betracht ziehen:

J Am Coll Cardiol. 2003 Jul 16;42(2):246-52.

Vitamin C and risk of coronary heart disease in women.

Osganian SK, Stampfer MJ, Rimm E, Spiegelman D, Hu FB, Manson JE, Willett WC.

Department of Medicine, Children's Hospital, Boston, Massachusetts, USA. stavroula.osganian@TCH.harvard.edu

OBJECTIVES: Our objective was to prospectively examine the relation between vitamin C intake and risk of coronary heart disease (CHD) in women. BACKGROUND: Results from prospective investigations of the relation between vitamin C intake and risk of CHD have been inconsistent. The lack of clear evidence for a protective association despite a plausible mechanism indicates the need to evaluate further the association between vitamin C intake and risk of CHD. METHODS: In 1980, 85,118 female nurses completed a detailed semiquantitative food-frequency questionnaire that assessed their consumption of vitamin C and other nutrients. Nurses were followed up for 16 years for the development of incident CHD (nonfatal myocardial infarction and fatal CHD). RESULTS: During 16 years of follow-up (1,240,566 person-years), we identified 1,356 incident cases of CHD. After adjustment for age, smoking, and a variety of other coronary risk factors, we observed a modest significant inverse association between total intake of vitamin C and risk of CHD (relative risk [RR] = 0.73; 95% confidence interval [CI] 0.57 to 0.94). Among women who did not use vitamin C supplements or multivitamins, the association between intake of vitamin C from diet alone and incidence of CHD was weak and not significant (RR = 0.86; 95% CI 0.59 to 1.26). In multivariate models adjusting for age, smoking, and a variety of other coronary risk factors, vitamin C supplement use was associated with a significantly lower risk of CHD (RR = 0.72; 95% CI 0.61 to 0.86). CONCLUSIONS: Users of vitamin C supplements appear to be at lower risk for CHD.

Antioxidant vitamins and coronary heart disease risk: a pooled analysis of 9 cohorts.

Knekt P, Ritz J, Pereira MA, O'Reilly EJ, Augustsson K, Fraser GE, Goldbourt U, Heitmann BL, Hallmans G, Liu S, Pietinen P, Spiegelman D, Stevens J, Virtamo J, Willett WC, Rimm EB, Ascherio A.

National Public Health Institute, Helsinki, Finland. paul.knekt@ktl.fi

BACKGROUND: Epidemiologic studies have suggested a lower risk of coronary heart disease (CHD) at higher intakes of fruit, vegetables, and whole grain. Whether this association is due to antioxidant vitamins or some other factors remains unclear. OBJECTIVE: We studied the relation between the intake of antioxidant vitamins and CHD risk. DESIGN: A cohort study pooling 9 prospective studies that included information on intakes of vitamin E, carotenoids, and vitamin C and that met specific criteria was carried out. During a 10-y follow-up, 4647 major incident CHD events occurred in 293 172 subjects who were free of CHD at baseline. RESULTS: Dietary intake of antioxidant vitamins was only weakly related to a reduced CHD risk after adjustment for potential nondietary and dietary confounding factors. Compared with subjects in the lowest dietary intake quintiles for vitamins E and C, those in the highest intake quintiles had relative risks of CHD incidence of 0.84 (95% CI: 0.71, 1.00; P=0.17) and 1.23 (1.04, 1.45; P=0.07), respectively, and the relative risks for subjects in the highest intake quintiles for the various carotenoids varied from 0.90 to 0.99. Subjects with higher supplemental vitamin C intake had a lower CHD incidence. Compared with subjects who did not take supplemental vitamin C, those who took >700 mg supplemental vitamin C/d had a relative risk of CHD incidence of 0.75 (0.60, 0.93; P for trend <0.001). Supplemental vitamin E intake was not significantly related to reduced CHD risk. CONCLUSIONS: The results suggest a reduced incidence of major CHD events at high supplemental vitamin C intakes. The risk reductions at high vitamin E or carotenoid intakes appear small.

Wobei vielleicht auch folgendes zu beachten ist:

http://www.aerztezeitung.de/docs/200...hrung/vitamine

[Milchknilch]

WHOLE VS. FRACTIONATED
OK, natural vs. synthetic. Let's start with Vitamin C. Most sources equate vitamin C with ascorbic acid, as though they were the same thing. They're not. Ascorbic acid is an isolate, a fraction, a distillate of naturally occurring vitamin C. In addition to ascorbic acid, vitamin C must include rutin, bioflavonoids, Factor K, Factor J, Factor P, Tyrosinase, Ascorbinogen, and other components. In addition, mineral co-factors must be available in proper amounts.
If any of these parts are missing, there is no vitamin C, no vitamin activity. When some of them are present, the body will draw on its own stores to make up the differences, so that the whole vitamin may be present. Only then will vitamin activity take place, provided that all other conditions and co-factors are present. Ascorbic acid is described merely as the "antioxidant wrapper" portion of vitamin C; ascorbic acid protects the functional parts of the vitamin from rapid oxidation or breakdown. (Somer p 58 "Vitamin C: A Lesson in Keeping An Open Mind" The Nutrition Report)

[rantanplan]

mensch rantanplan...bis heute warst du mir sympathisch, aber mit diesem avatar .....

Ich bin ja kompromissbereit. Wie wärs damit - ist zwar die gleiche Partei aber ein hübschers Gesicht. Mehr Entgegenkommen kann man ja nun wirklich nicht verlangen!

[rantanplan]

Hallo Milchknilch,

die Behauptung, dass Vitamin C als Einzelstoff keine Vitaminwirkung hätte, ist so einfach nicht korrekt. Die direkten Wirkungen von Vitamin C - sprich: "L-Threo-hex-2-enono-1,4-lacton u. dessen Derivate mit gleicher biol. Wirkung" (Pschyrembel) - sind ganz gut nachgewiesen (z.B. seine Rolle bei der Carnitin-, Catecholamin-, Kortikoid- und Collagensynthese, Radikalfänger ect.). Während Ascorbinsäure (bzw. dessen Abkömmlinge) zu den essentiellen Mikronährstoffen gehört, hat z.B, das angesprochene Rutin oder andere Flavonoide (von denen es ja unzählige gibt) einen solchen Status eben nicht und ich bezweifle, dass der Autor Gegenteiliges zu beweisen im Stande ist (was natürlich nicht heißt, dass Flavonoide wirkungslos seien).


Gruß

[drmaniac]

und jetzt sowas

http://www.spiegel.de/wissenschaft/m...374510,00.html

Hochdosiertes Vitamin C tötet Krebszellen

"Vitamin C könnte eines Tages in der Krebsbehandlung eingesetzt werden. Es müsste direkt in die Venen gespritzt werden, damit die Konzentration hoch genug ist, um Tumorzellen abzutöten...

...

Die Wissenschaftler untersuchten die Wirkung von Ascorbinsäure an zehn Krebszelllinien und vier Kulturen gesunder Körperzellen. Das Ergebnis war eindeutig: Das Vitamin C tötete gezielt die Krebszellen ab, während die gesunden Zelllinien nicht geschädigt wurden.

Damit die Krebszellen tatsächlich abstarben, musste das Vitamin C jedoch in so hohen Konzentrationen verabreicht werden, wie sie beim Menschen nur durch eine Infusion direkt in die Venen erreicht werden können. Die Ascorbinsäure führte zur Bildung von Wasserstoffperoxid, das den Tod der Krebszellen verursachte, stellten die Forscher weiter fest. Wasserstoffperoxid entstand dabei jedoch nur in der unmittelbaren Umgebung von Zellen und nicht im Blut

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