This could be tied to the infectious hypothesis of Alzheimers too - fasting for a period of time effectively 'resets' the immune system [1]. The infectious hypothesis is often associated with herpesviridae so I wonder if there's any studies that show an impact from intermittent fasting on chronic HSV.

[1] https://thesource.com/2018/11/21/fasting-for-72-hours-can-re...