Redox Therapy

Redox therapy is an unproven alternative cancer treatment that aims to treat cancer with redox chemical agents, usually given through the diet. This form of treatment involves the use of high doses of antioxidant chemicals, especially vitamin C (as nutritional ascorbic acid or more usually intravenous sodium ascorbate), but also lipoic acid, vitamin K₃ and coenzyme Q10, attempting to kill cancer cells while leaving healthy cells alive. Much of the research in this area follows the work of Linus Pauling, who was an early advocate of this idea.

However, the main way in which it is suggested that vitamin C (and other antioxidants) kills cancer cells is, paradoxically, by acting as a pro-oxidant. In the redox cycle in cancer cells, vitamin C cycles between ascorbate and dehydroascorbate. In this process, hydrogen peroxide is produced within the cell. Cancer cells, unlike other cells, have low amounts of antioxidant enzymes, notably catalase. In a healthy cell, catalase would convert peroxide to oxygen and water. However, in a cancer cell, the peroxide is thought to build up to toxic levels and kill the cell.

Some types of cancer cells have a much higher uptake of vitamin C than other cells. Vitamin C is structurally similar to glucose and can be transported by glucose pumps in cells, and cancer cells have a higher glucose uptake than other cells.

While levels of vitamin C in the blood are high enough to kill some cancers, vitamin C can be received orally, most cancers require, according to proponents of the therapy, intravenous injections of up to 100g of sodium ascorbate per day, at spaced intervals.