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).