The article kindly submitted here has the date October 7, 2015, referring to a study in <i>Science Translational Medicine</i>, and just today a group-edited blog post by Dr. Steven Novella on Science-Based Medicine[1] brings us up to date on a very recent study published by <i>Nature</i>.[2] As Dr. Novella puts it,<p>&quot;The study is based on the observation that with solid tumors, like melanoma, there is frequent dissemination of cancer cells through the blood (metastasis) but these cells are very inefficient at establishing a metastatic tumor. One reason for this is the immune system using ROS to essentially kill metastatic cells before they can be established. They found that cancer cells that do establish tumors tend to have mutations that make them resistant to oxidative stress.<p>&quot;Most relevant to this topic, however, they found that in mice exogenous antioxidants promoted distant metastasis. This suggests that if you have cancer and you take antioxidants, your chance of developing metastases is greater. Keep in mind most solid tumor are usually present for 2-3 years before they are diagnosed, so the risk potentially exists even for those who have not yet been diagnosed with cancer.<p>&quot;This has alarming implications given the popularity of antioxidant supplements.&quot;<p>[1] <a href="https:&#x2F;&#x2F;www.sciencebasedmedicine.org&#x2F;more-trouble-for-antioxidants&#x2F;" rel="nofollow">https:&#x2F;&#x2F;www.sciencebasedmedicine.org&#x2F;more-trouble-for-antiox...</a><p>[2] <a href="http:&#x2F;&#x2F;www.nature.com&#x2F;articles&#x2F;nature15726.epdf" rel="nofollow">http:&#x2F;&#x2F;www.nature.com&#x2F;articles&#x2F;nature15726.epdf</a>