There is no doubt it can be helped by diet and perhaps exogenous ketones or MCT oil.
Reversal to a degree has been proven. But reversal to a level of a young person is probably not possible.
The quicker it is diagnosed, the better the reversal. Better to avoid it in the first place, in large part can be helped by proper diet.
At least that is the way the current science looks.
Thread below on Alzheimer's