And instead of having separate methods for each kind of save that fetches the object and saves it, just fetch it once and modify it based on the updatedFields. As it is now, if there are 5 updated fields it will fetch it 5 times from the DB and save it 5 times. You could fetch it once, update it and then save it.
if (updates.getUpdatedFields().contains("journalists")) {
    articleService.setJournalists(updates.getJournalists());
} // etc
and then save it at the end