On the other hand, it's known that consuming the antioxidant vitamin E actually promotes the progression of lung cancer. Cancer cells are under oxidative stress so antioxidants can help them survive and grow.

https://www.lung.org/blog/antioxidants-lung-cancers

Just goes to show that biology is WAY more complicated than "if you want to prevent X then do Y" - especially at microbilogical scale. Genes influence each other for example, so by up- or downregulating stuff you are interfering in a highly complex, non-linear system with complex consequences.

Just look at this example of a gene regulation network: https://www.researchgate.net/figure/Different-visualizations...

The Vitamin E / NAC relationship are interesting. As far as I understand, there needs to be a balance of anti-oxidants (C, E, Selenium, etc). To make it worse there are so many formulations of Vitamin E you can buy (tocopherols, tocotrienols, etc). Sometimes its hard to tell from the studies what forms exactly were being used.

You may also find this interesting:

"NRF2 activation is a predictor of poor clinical outcomes in lung cancer. Given the widespread use of NRF2-inducing compounds such as resveratrol and sulforaphane, these findings raise important concerns about their safety in individuals at risk for or living with cancer."

https://link.springer.com/article/10.1007/s11357-025-01736-0

Many people eat high-sulforaphane containing foods for health benefits.

And finally from last week https://newatlas.com/diet-nutrition/vitamin-c-air-pollution-...

This was about 1000mg / day for humans.