Related Posts in WordPress (Doing many queries)

<?
        function get_related_posts($max_results = 4) {

                # Back up old $posts and $post variables, as get_posts will change those
                global $post, $posts;
                $post_backup = $post;
                $posts_backup = $posts;

                # Get terms from our custom taxonomy
                $terms = get_the_terms($post->ID , 'my-cusotm-taxonomy');

                # Create arrays to hold our already-added posts and the result of this function
                $do_not_duplicate[] = $post->ID;
                $total_matches = array();

                # Make sure there are any taxonomy terms we can loop through.
                if(!empty($terms) AND !is_wp_error($terms)) {

                        # Loop over each term and do a new get_posts query for posts matching that term
                        foreach ($terms as $term) {
                                $posts = get_posts(array(
                                        'post_type' => 'news',
                                        'custom-tag' => $term->slug,
                                        'posts_per_page' => 4,
                                        'post__not_in' => $do_not_duplicate,
                                ));

                                # If any posts are found by that query,
                                # add them to $do_not_duplicate, so they won't be added again later,
                                # then push them into our $total_matches array
                                if($posts) {
                                        foreach ($posts as $post) {
                                                $do_not_duplicate[] = $post->ID;
                                                array_push($total_matches, $post);
                                        }
                                }
                        }

                        # If we found any related posts above, show them.
                        if (count($total_matches) > 0)
                                $total_matches = array_slice($total_matches, 0, $max_results);
                }

                # Restore backups
                $post = $post_backup;
                $posts = $posts_backup;

                # Return result
                return $total_matches;
        }