Interesting, Debbie & Plumster. Was this water filter brand specifically recommended via the series?
If you go to Dr. Hyman's site you can get a discount on the reverse osmosis fiter: https://brokenbrain.com/pages/dr-hyman-filter.
I recall a Tom Dayspring comment, which Stavia also posted about "Dayspring also reassured us that there aren't enough plant sterols in a whole foods diet to be an issue." Tom Dayspring MD is a known lipid educator and was a guest expert here a few years ago.