I read some time ago about the Keto diet showing good results even in Alzheimer/dementia cases. Keto is not the same as low carb but it's close enough.
Our molecular biology and internal chemical reactions are still areas of research in early phases.
Just on a different topic, but in the same direction - last 10 years research discovered that immunity boosting has much better results in certain types of cancer than all the other non-surgery treatments (chemical or radiation).
"Diet supplementation with ketone bodies (acetoacetate and β‐hydroxybuturate) or medium‐length fatty acids generating ketone bodies has consistently been found to cause modest improvement of mental function in Alzheimer's patients. It was suggested that the therapeutic effect might be more pronounced if treatment was begun at a pre‐clinical stage of the disease instead of well after its manifestation."
