The dose also matters. In any case if ROS is generated then it is by definition a pro-oxidant, which can happen with megadoses of antioxidants.

Fallleaves, great post thank you. I was confused about all that.

Falleaves, Heidihill, thank you both for posting these links. Very informative.

Another:

Oxidative stress inhibits distant metastasis by human melanoma cells

• Elena Piskounova,
• Michalis Agathocleous,
• Malea M. Murphy,
• Zeping Hu,
• Sara E. Huddlestun,
• Zhiyu Zhao,
• A. Marilyn Leitch,
• Timothy M. Johnson,
• Ralph J. DeBerardinis
• & Sean J. Morrison

Nature

(2015)

doi:10.1038/nature15726

Published online

14 October 2015

Solid cancer cells commonly enter the blood and disseminate systemically, but are highly inefficient at forming distant metastases for poorly understood reasons. Here we studied human melanomas that differed in their metastasis histories in patients and in their capacity to metastasize in NOD-SCID-Il2rg^−/− (NSG) mice. We show that melanomas had high frequencies of cells that formed subcutaneous tumours, but much lower percentages of cells that formed tumours after intravenous or intrasplenic transplantation, particularly among inefficiently metastasizing melanomas. Melanoma cells in the blood and visceral organs experienced oxidative stress not observed in established subcutaneous tumours. Successfully metastasizing melanomas underwent reversible metabolic changes during metastasis that increased their capacity to withstand oxidative stress, including increased dependence on NADPH-generating enzymes in the folate pathway. Antioxidants promoted distant metastasis in NSG mice. Folate pathway inhibition using low-dose methotrexate, ALDH1L2 knockdown, or MTHFD1 knockdown inhibited distant metastasis without significantly affecting the growth of subcutaneous tumours in the same mice. Oxidative stress thus limits distant metastasis by melanoma cells in vivo.

If I were to guess, I'd say alcohol causes oxidation.... we'll get the answer.

Thanks Fallleaves. Great article, I saved it. And that is why everything in moderation....