How do I deal?

I managed to scare my mother with the threat of science. And when MeMum gets scared, she gets hostile. And since I don't want her to shut me down entirely, I must relent.

I have to maintain the avenues of communication.

I have to be the one making the tough decisions when those decisions are out of MeMum's reach. And that's a possibility that I didn't want to be looming, just yet.

And once Mum's put her foot down about a thing, it stays planted. For good or ill. Even when it's against her own self-interest.

So, she's decided she's going to die if she is diagnosed with Dementia, and no attempted intervention is going to stop her. And I know for a fact that GP's don't diagnose Dementia until it's way too late to get the person back. So MeMum is "safe" from a diagnosis until a later date.

How do I deal with that? How do I cope with the fact that my mother actively despises the thing that can save her mind and her life? How do I deal with the fact that she doesn't want to live?

It's not suicidal ideation, far from it. It's more... established pattern ideation. The established pattern of staying away from fats, regardless of their health levels, is the Absolute Best Thing. And though MeMum's accepted that highly-processed carbs are Bad, she's still not giving herself the calories she needs in the form of healthy fats.

Which means that her current "Mediterranean" Diet is not only no longer Mediterranean, but also not good for sustained liver function. The body needs fuel in one form or the other, and those forms are sugar or fat. One of the two.

Choose sugar, and you need to lower the fat content or balloon up and get all the bad things we fear.

Choose fat, and you need to lower the sugars in all forms or suffer likewise.

Remove both, and you fry your liver while you're still using it. That's bad.

But, mother knows best. Or else. She's determined to do this to herself because she thinks it's healthy. I can see the incoming disaster like Noah knew about the flood, but all I get out of warning her is hostility and an obstinate adherence to the pattern.

So it's let her die in her own way, sticking to the pattern that's going to kill her... or try and save her and be shunned for it while she still sticks to the pattern that's going to kill her.

Doing nothing, I will feel the guilt for the rest of my life.

Doing something, we'll be estranged while she continues to do her thing. And in the end, the result will be the same.

Staying silent while I watch her wither in one way or another feels... worse than choosing evil, to be honest. It's heart-breaking.

And it doesn't help that, in order to remain close enough to enact any form of rescue at all, I have to sit still and shut up while a mis-informed doctor shovels dated bullshit in my general direction.

I do not know what to do. My conscience compels me to speak up. My need to be there for her means I can't do that?

Devil, meet dark blue sea. Rock, meet hard place.

No matter what I do, I'm going to feel horrible about the results.