BACKGROUND: Antioxidants are believed to prevent many types of disease. Some previous studies suggest that dietary supplementation with vitamin C results in a decrease in the level of one of the markers of oxidative damage-8-oxoguanine in the DNA of peripheral blood mononuclear cells (PBMC). AIM OF TRIAL: To investigate the effect of different dose levels of dietary supplementation with vitamin C on oxidative DNA damage. METHODS: A randomised double-blind placebo-controlled trial was carried out using three different levels (80, 200 and 400 mg) of dietary vitamin C supplementationin a healthy population of 160 volunteers; supplementation was for a period of 15 weeks followed by a 10 week washout period. Peripheral blood samples were obtained every 5 weeks from baseline to 25 weeks. RESULTS: An increase in PBMC vitamin C levels was not observed following supplementation in healthy volunteers. There was no effect found on 8-oxoguanine measured using HPLC with electrochemical detection for any of the three supplemented groups compared to placebo. 8-oxoadenine levels were below the limit of detection of the HPLC system used here. CONCLUSIONS: Supplementation with vitamin C had little effect on cellular levels in this group of healthy individuals, suggesting their diets were replete in vitamin C. The dose range of vitamin C used did not affect oxidative damage in PBMC DNA.
RCT Entities:
BACKGROUND: Antioxidants are believed to prevent many types of disease. Some previous studies suggest that dietary supplementation with vitamin C results in a decrease in the level of one of the markers of oxidative damage-8-oxoguanine in the DNA of peripheral blood mononuclear cells (PBMC). AIM OF TRIAL: To investigate the effect of different dose levels of dietary supplementation with vitamin C on oxidative DNA damage. METHODS: A randomised double-blind placebo-controlled trial was carried out using three different levels (80, 200 and 400 mg) of dietary vitamin C supplementation in a healthy population of 160 volunteers; supplementation was for a period of 15 weeks followed by a 10 week washout period. Peripheral blood samples were obtained every 5 weeks from baseline to 25 weeks. RESULTS: An increase in PBMC vitamin C levels was not observed following supplementation in healthy volunteers. There was no effect found on 8-oxoguanine measured using HPLC with electrochemical detection for any of the three supplemented groups compared to placebo. 8-oxoadenine levels were below the limit of detection of the HPLC system used here. CONCLUSIONS: Supplementation with vitamin C had little effect on cellular levels in this group of healthy individuals, suggesting their diets were replete in vitamin C. The dose range of vitamin C used did not affect oxidative damage in PBMC DNA.
Authors: H E Poulsen; A Weimann; J T Salonen; K Nyyssönen; S Loft; J Cadet; T Douki; J L Ravanat Journal: Nature Date: 1998-09-17 Impact factor: 49.962
Authors: M Levine; C Conry-Cantilena; Y Wang; R W Welch; P W Washko; K R Dhariwal; J B Park; A Lazarev; J F Graumlich; J King; L R Cantilena Journal: Proc Natl Acad Sci U S A Date: 1996-04-16 Impact factor: 11.205
Authors: C G Fraga; P A Motchnik; M K Shigenaga; H J Helbock; R A Jacob; B N Ames Journal: Proc Natl Acad Sci U S A Date: 1991-12-15 Impact factor: 11.205
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