mysql_tzinfo_to_sql /usr/share/zoneinfo - how to update without server restart?

Our application serves people around the globe, and we update the timezones every month or so with:

mysql_tzinfo_to_sql /usr/share/zoneinfo | mysql -u root mysql

Unfortunately, a zone which was cached by mysqld, stays cached, and the only way to purge that cache seems to be restarting mysqld.

Is there a better way to do it (withot restarting mysqld)?