“The antioxidants caused a 2.8-fold increase in lung tumors, made the tumors more invasive and aggressive, and caused the mice to die twice as quickly – all compared to mice not given antioxidants.
When the antioxidants were added to human lung tumor cells in lab dishes, they also accelerated cancer growth.”
Here’s the mechanism:
“What seems to happen is that antioxidants indeed decrease DNA damage, as expected. But the damage becomes so insignificant as to be undetectable by the cell. The cell therefore does not deploy its cancer-defense system.”
The scientists stressed that the results do not pertain to foods such as fruits and vegetables that are naturally high in antioxidants.”
– Antioxidants Including Vitamin E Can Promote Lung Cancer: Study, Reuters, 29 January 2014
Co-author of the study, Per Lindahl, said “antioxidants allow cancer cells to escape cells’ own defense system,” letting existing tumors, even those too small to be detected, proliferate uncontrollably.
Here’s the study:
Antioxidants Accelerate Lung Cancer Progression in Mice, Science Translational Medicine, 29 January 2014
“Antioxidants are widely used to protect cells from damage induced by reactive oxygen species (ROS). The concept that antioxidants can help fight cancer is deeply rooted in the general population, promoted by the food supplement industry, and supported by some scientific studies.
We show that supplementing the diet with the antioxidants N-acetylcysteine (NAC) and vitamin E markedly increases tumor progression and reduces survival in mouse models of B-RAF– and K-RAS–induced lung cancer. RNA sequencing revealed that NAC and vitamin E, which are structurally unrelated, produce highly coordinated changes in tumor transcriptome profiles, dominated by reduced expression of endogenous antioxidant genes. NAC and vitamin E increase tumor cell proliferation by reducing ROS, DNA damage, and p53 expression in mouse and human lung tumor cells. Inactivation of p53 increases tumor growth to a similar degree as antioxidants and abolishes the antioxidant effect.
Thus, antioxidants accelerate tumor growth by disrupting the ROS-p53 axis. Because somatic mutations in p53 occur late in tumor progression, antioxidants may accelerate the growth of early tumors or precancerous lesions in high-risk populations such as smokers and patients with chronic obstructive pulmonary disease who receive NAC to relieve mucus production.”
As it stands, smokers are being advised to get more antioxidants, e.g. “Individuals who smoke require 35 mg/day more vitamin C than nonsmokers.” Hm. Best to eat an orange and skip the supplement.
Dr. Campbell described this, in a conceptual way, in his book, “Whole.” When you put a chemical – in isolated, concentrated form – into the chemical soup that is our body, you can’t easily predict how all the other chemicals are going to respond.
Dr. Paul Marantz, epidemiologist at Albert Einstein College of Medicine:
“It’s disappointing but not surprising that people’s beliefs are not modified by scientific evidence. … People so want to believe there is a magic bullet out there.”