diff --git includes/menu.inc includes/menu.inc
index 3519636..c793ae3 100644
--- includes/menu.inc
+++ includes/menu.inc
@@ -1092,6 +1092,10 @@ function menu_tree_all_data($menu_name, $link = NULL, $max_depth = NULL) {
  *   The named menu links to return.
  * @param $max_depth
  *   (optional) The maximum depth of links to retrieve.
+ * @param $only_active_trail
+ *   (optional) Whether to only return the links in the active trail (TRUE)
+ *   instead of all links on every level of the menu link tree (FALSE). Defaults
+ *   to FALSE. Internally used for breadcrumbs only.
  *
  * @return
  *   An array of menu links, in the order they should be rendered. The array
@@ -1100,7 +1104,7 @@ function menu_tree_all_data($menu_name, $link = NULL, $max_depth = NULL) {
  *   submenu below the link if there is one, and it is a subtree that has the
  *   same structure described for the top-level array.
  */
-function menu_tree_page_data($menu_name, $max_depth = NULL) {
+function menu_tree_page_data($menu_name, $max_depth = NULL, $only_active_trail = FALSE) {
   $tree = &drupal_static(__FUNCTION__, array());
 
   // Load the menu item corresponding to the current page.
@@ -1110,6 +1114,17 @@ function menu_tree_page_data($menu_name, $max_depth = NULL) {
     }
     // Generate a cache ID (cid) specific for this page.
     $cid = 'links:' . $menu_name . ':page:' . $item['href'] . ':' . $GLOBALS['language']->language . ':' . (int) $item['access'] . ':' . (int) $max_depth;
+    // If we are asked for the active trail only, and $menu_name has not been
+    // built and cached for this page yet, then this likely means that it
+    // won't be built anymore, as this function is invoked from
+    // template_preprocess_page(). So in order to not build a giant menu tree
+    // that needs to be checked for access on all levels, we simply check
+    // whether we have the menu already in cache, or otherwise, build a minimum
+    // tree containing the breadcrumb/active trail only.
+    // @see menu_set_active_trail()
+    if (!isset($tree[$cid]) && $only_active_trail) {
+      $cid .= ':trail';
+    }
 
     if (!isset($tree[$cid])) {
       // If the static variable doesn't have the data, check {cache_menu}.
@@ -1146,13 +1161,18 @@ function menu_tree_page_data($menu_name, $max_depth = NULL) {
                   $active_trail[$active_link['p' . $i]] = $active_link['p' . $i];
                 }
               }
+              // If we are asked to build links for the active trail only, skip
+              // the entire 'expanded' handling.
+              if ($only_active_trail) {
+                $tree_parameters['only_active_trail'] = TRUE;
+              }
             }
           }
           $parents = $active_trail;
 
           $expanded = variable_get('menu_expanded', array());
           // Check whether the current menu has any links set to be expanded.
-          if (in_array($menu_name, $expanded)) {
+          if (!$only_active_trail && in_array($menu_name, $expanded)) {
             // Collect all the links set to be expanded, and then add all of
             // their children to the list as well.
             do {
@@ -1202,9 +1222,12 @@ function menu_tree_page_data($menu_name, $max_depth = NULL) {
  *   (optional) An associative array of build parameters. Possible keys:
  *   - expanded: An array of parent link ids to return only menu links that are
  *     children of one of the plids in this list. If empty, the whole menu tree
- *     is built.
+ *     is built, unless 'only_active_trail' is TRUE.
  *   - active_trail: An array of mlids, representing the coordinates of the
  *     currently active menu link.
+ *   - only_active_trail: Whether to only return links that are in the active
+ *     trail. This option is ignored, if 'expanded' is non-empty. Internally
+ *     used for breadcrumbs only.
  *   - min_depth: The minimum depth of menu links in the resulting tree.
  *     Defaults to 1, which is the default to build a whole tree for a menu, i.e.
  *     excluding menu container itself.
@@ -1282,6 +1305,9 @@ function _menu_build_tree($menu_name, array $parameters = array()) {
     if (!empty($parameters['expanded'])) {
       $query->condition('ml.plid', $parameters['expanded'], 'IN');
     }
+    elseif (!empty($parameters['only_active_trail'])) {
+      $query->condition('ml.mlid', $parameters['active_trail'], 'IN');
+    }
     $min_depth = (isset($parameters['min_depth']) ? $parameters['min_depth'] : 1);
     if ($min_depth != 1) {
       $query->condition('ml.depth', $min_depth, '>=');
@@ -2171,7 +2197,10 @@ function menu_set_active_trail($new_trail = NULL) {
 
     // There is a link for the current path.
     if ($preferred_link) {
-      $tree = menu_tree_page_data($preferred_link['menu_name']);
+      // Pass TRUE for $only_active_trail to make menu_tree_page_data() build
+      // a stripped down menu tree containing the active trail only, in case
+      // the given menu has not been built in this request yet.
+      $tree = menu_tree_page_data($preferred_link['menu_name'], NULL, TRUE);
       list($key, $curr) = each($tree);
     }
     // There is no link for the current path.
diff --git includes/theme.inc includes/theme.inc
index 658128c..b2e34bc 100644
--- includes/theme.inc
+++ includes/theme.inc
@@ -2257,7 +2257,6 @@ function template_preprocess_page(&$variables) {
 
   $variables['base_path']         = base_path();
   $variables['front_page']        = url();
-  $variables['breadcrumb']        = theme('breadcrumb', array('breadcrumb' => drupal_get_breadcrumb()));
   $variables['feed_icons']        = drupal_get_feeds();
   $variables['language']          = $GLOBALS['language'];
   $variables['language']->dir     = $GLOBALS['language']->direction ? 'rtl' : 'ltr';
@@ -2269,6 +2268,11 @@ function template_preprocess_page(&$variables) {
   $variables['site_name']         = (theme_get_setting('toggle_name') ? filter_xss_admin(variable_get('site_name', 'Drupal')) : '');
   $variables['site_slogan']       = (theme_get_setting('toggle_slogan') ? filter_xss_admin(variable_get('site_slogan', '')) : '');
   $variables['tabs']              = theme('menu_local_tasks');
+  // Build the breadcrumb last, so as to increase the chance of being able to
+  // re-use the cache of an already rendered menu containing the active link
+  // for the current page.
+  // @see menu_tree_page_data()
+  $variables['breadcrumb']        = theme('breadcrumb', array('breadcrumb' => drupal_get_breadcrumb()));
   $variables['title']             = drupal_get_title();
 
   if ($node = menu_get_object()) {