Lowering security is only risky if you're using Access apps where you have no idea of their origin. So long as you're using all internal and/or trusted sources, and not just opening random DBs that show up in email, then you're fine.
If you're paranoid, you can always scan DBs and such with a good virus scanner, or you can open Access, change the security level, and then open the DB in question. Otherwise, it's basically a CYA for MS. They can say, "We told you so!" if something gets fubared.
Bottom line: know your DB data sources. Don't just randomly open things.