Submitted to: Free Radicals in Biology and Medicine
Publication Type: Peer reviewed journal
Publication Acceptance Date: 2/17/2005
Publication Date: 5/17/2005
Citation: Hininger, I., Waters, R., Osman, M., Garrel, C., Fernholz, K., Roussel, A.M., Anderson, R.A. 2005. Acute prooxidant effects of vitamin c in EDTA chelation therapy and long term antioxidant benefits of therapy. Free Radicals in Biology and Medicine. 38:1565-1570. Interpretive Summary: Antioxidants play a key role in the prevention of chronic diseases such as diabetes and cardiovascular diseases. An efficient antioxidant network is essential in the prevention of these diseases and improved antioxidant status may lead to their alleviation and(or) prevention. Certain metals such as lead, cadmium and iron may lead to decreased antioxidant status and these metals can be removed by chelation therapy. During chelation therapy, high levels of the antioxidant, vitamin C, are added during treatment. While low levels of vitamin C are known to function as antioxidants, high levels may have prooxidant properties and possible negative effects on health. We determined the antioxidant status of people within one hour of chelation therapy with and without the normal amount of vitamin C added during chelation treatment. Our data demonstrated that vitamin C had strong negative effects on the antioxidant status of patients and also caused DNA damage during the first day of treatment. During long-term therapy, more than 16 sessions, prooxidant effects of vitamin C were not present and there were improvements in overall antioxidant status. These data demonstrate that the amount of vitamin C used in the chelation treatment of patients with diseases such as diabetes and cardiovascular diseases should be closely monitored. This work should be of benefit to people with these diseases and the medical personnel involved in the treatment of diseases associated with dietary antioxidants and status.
Technical Abstract: Chelation therapy is thought to not only remove contaminating metals but also to decrease free radical production. EDTA chelation therapy, containing high doses of vitamin C as an antioxidant, is often used in the treatment of diseases such as diabetes and cardiovascular diseases but the effectiveness of this treatment may be variable and its efficacy has not been demonstrated conclusively. We administered a standard EDTA cocktail solution with or without 5 g of sodium ascorbate. Oxidative stress markers including plasma malondialdehyde, protein thiol groups, total and oxidized glutathione, DNA damage and antioxidant enzymes were measured for each patient before and after a chelation therapy session, and after sixteen sessions. One hour following the standard chelation therapy, there were highly significant prooxidant effects on lipids, proteins and DNA associated with decreased activities of red blood cell glutathione peroxidase and superoxide dismutase while in absence of sodium ascorbate, there were no signs of oxidative damage. After 16 sessions of standard chelation therapy, in the absence of nutrient supplements, the prooxidant effects were reversed and plasma peroxide levels monitored by MDA were significantly decreased and all of the other oxidative stress markers were unchanged. In summary, multiple sessions of EDTA chelation therapy protect lipids against oxidative damage. However, standard high amounts of vitamin C added to EDTA chelation solutions also display short-term prooxidant effects within one hour of each session. Therefore, the amount of vitamin C utilized in chelation therapy should be closely monitored.