Simvastatin may or may not cross the blood brain barrier but this doesn't prove that it causes harm.
This is a link to the original Cochrane database article which was looking at primary prevention, that is, drugs given to prevent disease in those who have none.
I can't see anything about side effects or memory loss.
http://summaries.coch...ardiovascular-disease
It is further discussed here
http://www.nhs.uk/new...n-drugs-examined.aspx
Not my area of expertise, but I'm interested to read up about the subject as both sons think I should be on a statin for primary prevention because of family history, but I 'm resisting - they listen to cardiologists too much!
The moral is best not to rely on The Daily Mail for medical advice!