A new research explains why antioxidant supplements cannot protect against cancer.
Researchers David Tuveson, M.D., Ph.D., Professor and Director of Research for the Lustgarten Foundation, and Navdeep S. Chandel, Ph.D., of the Feinberg School of Medicine at Northwestern University, say taking antioxidant pills or eating large quantities of foods rich in antioxidants might not be beneficial against cancer.
They explain that this happens because they do not act at the critical site in cells where tumor-promoting 'reactive oxygen species' are produced. Rather supplements and dietary antioxidants generally accumulate at scattered distant sites in the cell, "leaving tumor-promoting ROS relatively unperturbed," the researchers said in the press release.
The team said that their observations were based on recent advances in the understanding of the system in our cells that establishes a natural balance between oxidizing and anti-oxidizing compounds. These compounds are involved in so-called redox (reduction and oxidation) reactions essential to cellular chemistry.
Quantities of both ROS and natural antioxidants are higher in cancer cells - the ironically higher levels of antioxidants being a natural defense by cancer cells to keep their higher levels of oxidants in check, so growth can continue. Actually, researchers say, therapies that increase the levels of oxidants in cells may be beneficial, whereas those that act as antioxidants may further stimulate the cancer cells.
Interestingly, radiation therapy kills cancer cells by dramatically raising levels of oxidants. The same is true of chemotherapeutic drugs - they kill tumor cells via oxidation, the press release added.
The study "The Promise and Perils of Antioxidants for Cancer Patients" is published in The New England Journal of Medicine.
