Not yet investigated
What we have so far
They lower LDL by competing with cholesterol for absorption. In the rare people who absorb sterols themselves, that same chemistry causes premature atherosclerosis.
This star is on the map because the show intends to take the question apart properly — the trials, how it is actually tested, whether the thing sold is the thing studied. That work is not done yet, and nothing here should be read as a conclusion. When the investigation is published it will appear on this page.