@gatita - your original post was in August, but seems to me that almost everything is pointing to keto being good for almost everybody in this respect, ApoE4 gene or not. Ketosis - implying blood sugar readings that are lower than they’d be if not in ketosis - seems to me to be very desirable, given the connections between persistently high blood sugar levels and neurodegenerative disease that I’m seeing more and more about these days.
Specific to Alzheimer’s disease - ketones easily cross the blood-brain barrier, and if they are being used to fuel the brain, then the brain isn’t dependent on glucose. The brain needs fuel to make adenosine triphosphate (ATP). ATP is a huge deal - for all our cells it’s what keeps things going. Amazingly, every day we use and recycle our body weight in ATP.
One of the most, if not the most, prominent markers of Alzheimer’s disease is reduced glucose metabolism in the brain. Endothelial cells in the brain are responsible for getting glucose across the blood-brain barrier, and they contain a special protein transporter (‘GLUT1’ or ‘Glucose transporter 1’) for this purpose.
If there is a problem with the endothelial cells and/or a deficiency in GLUT1, things are really changed for the crossing of the blood-brain barrier by glucose and the function of the neurons that are so dependent on the ATP they get from their fuel - the neurons starve, to some extent.
If ketones are the fuel, the disruption in energy supply from the lack of glucose crossing the blood-brain barrier may be solved, as simple as that.
For Alzheimer’s disease, the way we break down Apolipoprotein E and how well we clean up the breakdown products is very important. Protein buildups cause some neurodegenerative diseases, becoming toxic if not gotten rid of. “Tau tangles” and “amyloid plaques” are a couple of types of these. One study (I’ll put a link at the end of this post) indicates that people with the ApoE4 gene may have more buildup of the protein breakdown products.
ApoE4 or not, autophagy would seem to be very important here, as an aid to getting rid of the “bad stuff.” I think that ketogenic eating and fasting provides an excellent foundation, here.