Erectile dysfunction at 29. No morning wood for years (unless eating lots of starch and fat before bed).

[LLight]

Maybe it's like cancer where the pathological metabolism causes the mutation as opposed to the mutation causing the cancer. In other words the metabolism, say compromised oxygen utilization or oxygen sinks (iron/ lipofuscin) causing issues with deuterium buildup further slowing things down, as opposed to the deuterium being the direct cause.

Agreed. Deuterium link to diseases is an interesting theory but I fail to see how it could be the real cause of diseases (but a failure of deuterium depletion mechanism could be a part). Moreover, except if someone uses DDW with a really low deuterium concentration, the deuterium content of a water restricted carnivore ketogenic diet is still not too far from the deuterium content of a normal diet I believe (relatively to the magnitude of "normal" concentrations). There might exist non-linear signaling effects but I don't understand why it should matter so much in terms of deuterium quantity.

Regarding dry fasting / water restriction, I think other mechanisms might be at play, and they could be of two kinds, point-in-time or recurrent depending they stem from prolonged or intermittent dry fasts.

Some people seem to get benefits that last for more than the duration of the fast (e.g. depression or digestive issues relieved, reduced bloating, disapearance of a persistent pain in a joint, eye floaters or eczema).

From the testimonies I have read, I believe that those effects are due to acute detoxication (like black and greasy stools and sediments which makes me think that prolonged dry fasting can acts like some sort of liver/gallblader flush for some, urine of strange color), vasopressin/oxytocin levels reset (some people report having less needs for water and less sugar cravings which may be linked to oxytocin), or drastic loss of water that allows cells to regain their normal metabolism (people regain their energy).

I also think that there might be benefits from intermittent dry fasting like a sustained osmolyte metabolism, circadian rhythms entrainment and digestive health (increased gut acidity and bile acid production), minor detoxication increase (via enzymes and transcription factors like NRF2 and FXR), slight elevation of vasopressin and oxytocin that promotes fat loss and might lower anxiety. I also wonder if dry fasting can help by promoting testosterone/androgens production.

Sorry for the laundry list of hypotheses, I think I needed to synthesize what my thoughts about it are currently