Antioxidants Accelerate Cancers Rather than Prevent Them
Antioxidants have long been considered an effective way to protect yourself against cancer, but a new study shows that not only is that not true, but they in fact accelerate the rates of certain cancers.
As described in The New England Journal of Medicine, virtually all clinical trials conducted in the Cold Spring Harbor Laboratory at Northwestern University have dashed consumers' hopes who believed in the added benefit of taking antioxidant supplements and eating antioxidant-rich foods.
The tests failed to show that antioxidants have any protective effect against cancer, and in several trials antioxidant supplementation has been linked with increased rates of certain cancers. In one trial, smokers taking extra beta carotene had higher, not lower, rates of lung cancer.
Based on a recent improved understanding of how cells establish a natural balance between oxidizing and anti-oxidizing compounds in the body, researchers propose why antioxidant supplements might not be working to reduce cancer development, and why they may actually being doing more harm than good.
These compounds are involved in so-called redox (reduction and oxidation) reactions essential to cellular chemistry.
Oxidants, like hydrogen peroxide, are essential in small amounts, but can become toxic if too much is present. Cells in the body naturally generate their own antioxidants to neutralize them. It's not unfathomable to imagine then why so many people believe that by boosting their antioxidant intake they can counter the effects of similarly toxic "reactive oxygen species," or ROS.
What's more, it is known that cancer cells generate higher levels of ROS to help them grow.
The research team believes that antioxidant supplements fail to benefit us because they do not act at the critical site in cells where tumor-promoting ROS are produced - the cellular "powerhouse" known as the mitochondria.
Cancer cells in fact contain both ROS and antioxidants (as a natural defender). Interestingly, researchers suggest therapies that raise the levels of oxidants in cells may be beneficial, whereas those that act as antioxidants may further stimulate the cancer cells. "Genetic or pharmacologic inhibition of antioxidant proteins," according to the press release, may also be an effective type of therapy.
The key challenge, they say, is to identify antioxidant proteins and pathways in cells that are used only by cancer cells and not by healthy cells.