Antioxidants are now an iconic example of premature hype making its way into marketing and the public consciousness long before the science is adequately understood. There are multiple lessons to be learned in this story, and a new study just emphasizes those lessons further.
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The new study
With this background, a recent study published in Nature concerning antioxidants and metastatic cancer should not be a surprise.
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.
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.
This has alarming implications given the popularity of antioxidant supplements.
Lessons
To emphasize the lessons from this iconic story of supplement industry misadventure:
-The body is complex, and we should be skeptical of any simplistic notions of the effects of our interventions
-We need to respect the natural homeostatic mechanisms that evolved and not think that we can easily improve them
-More is not always better
-Be skeptical of clinical claims based on pre-clinical or basic science; until we study an intervention’s net health effects, we cannot really know what they will be
-We have yet more evidence that for the average person the best advice is to eat a well-rounded diet with plenty of fruits and vegetables, but extra supplements (and especially high dose supplements) are like unnecessary and even counterproductive.
https://www.sciencebasedmedicine.org...-antioxidants/
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