Disclaimer: I’m meat-cancer agnostic. *IF* meat causes cancer (and I don’t think it does), it happens extremely slowly and only at very high levels of intake: to get statistically significant risk ratios, researchers usually look to top vs. bottom quartiles, which is quite a large difference in intake.
Meat-cancer studies Tl;dr: some studies show positive associations, some neutral, and none are negative (ie, it’s unlikely meat prevents cancer).
That said, if meat does cause cancer, here is how it might happen:
1. The “Maybes:” AGEs, leucine/mTOR, methionine, etc., but only in combination with numbers 2 & 3. Not by themselves.
2. Circadian arrhythmia and cancer: potential mechanisms
3. Most animal foods have a lot of linoleate 18:2n6 or at least a lot more n6 than n3 (grass-fed is usually a little better in this context). More on this below.
One aspect of circadian arrhythmia manifests as low or mistimed melatonin.
This is one of the most compelling studies on the melatonin/cancer link, imo (also discussed HERE): Melatonin-depleted blood from premenopausal women exposed to light at night stimulates growth of human breast cancer xenografts in nude rats (Blask et al., 2005)
Melatonin inhibits tumor linoleate uptake, but you need a high peak for this to happen. Artificial light at night prevents this.
Many cell types proliferate at night; ideally, tumors would love a low melatonin high linoleate milieu at night. And maybe an abundance of those things listed in #1 above.
What’s up with the linoleate, you ask?
Tumors turn linoleate into 13-HODE, a potent mitogen (Dauchy et al., 2015).
By this logic, vege oils should be worse than meat (they probably are), depending on the importance of the factors listed in #1.
-In any case, replacing some steak with seafood may be prudent.
-No artificial light at night.
-I don’t know if melatonin supps will work in this #context, but doubt they’d hurt.
-By preserving endogenous melatonin production, blue blockers should definitely help.
-Same goes for an earlier eating pattern and sunlight in the morning (or at least some bright light).
Linoleate… sheesh