A new study published in the journal Nature suggests that antioxidants are capable of aiding the quick spread of cancer cells in lab mice, underscoring the fact that humans could be at risk of the same compound.

Scientists have always associated antioxidants with lower cancer risks and slowing down the aging process, but this new research about the possibility of the substance enhancing the spread of cancer cells appears to contradict what researchers had always promoted as the benefits of antioxidants.

In lab studies conducted on mice, the researchers were able to find that antioxidants promoted cancer cells spread; forcing researchers to suggest that antioxidants may be good for humans but it is best to stop when they notice signs of cancers in the body.

Dr. Sean Morrison, the director of the Children’s Medical Center Research Institute at UT Southwestern (CRI), noted that metastasis – the process whereby cancer cells move from one part of the body to the other, may be enhanced with antioxidants.

Morrison noted that mice transplanted with melanoma cells from patients and then given N-acetylcysteine – antioxidants used in bodybuilding and nutritional supplements, did not show this result. According to him, the injection of antioxidants to the mice allowed more of the metastasizing melanoma cells to survive, increasing the risks of melanoma in the lab rats.

However, people who do not have cancer have been projected to benefit from antioxidants which may reduce harm from very reactive oxidative molecules created by normal body metabolism. The results of the study have not been carried out in normal people, but it indicates that cancer is better treated with pro-oxidants while patients should not supplement their diet with large amounts of antioxidants.

“We discovered that metastasizing melanoma cells experience very high levels of oxidative stress, which leads to the death of most metastasizing cells,” said Dr. Sean Morrison, CRI Director and Mary McDermott Cook Chair in Pediatric Genetics at UT Southwestern Medical Center. “Administration of antioxidants to the mice allowed more of the metastasizing melanoma cells to survive, increasing metastatic disease burden.”