Causes gout.
Literally first thing when googling. You would have to eat humongous amounts of this very salty tiny fish to see any long term effect. The salt itself would probably kill you earlier.
Anchovies in Spanish mean normally only the canned, very salty, thing. If you want to buy the fresh fish, there is a different word for it. The third option to consume it is marinated on vinegar, that also uses the fish name (plus "on vinegar").
No ones getting gout from anchovies without having some other extremely decadent diet choices paired with it.