Date	Event	Description
8 May 2013	New search has been performed	Searches conducted. We included four new trials and performed new analyses (Al‐Ansari 2010; Miraglia Del Giudice 2012; Ipek 2011; Luo 2011). Our conclusions remain unchanged.
7 June 2010	New search has been performed	Searches conducted. We included three new trials and conducted new analyses (Anil 2010; Grewal 2009; Luo 2010). The conclusions remain unchanged.
10 May 2010	New search has been performed	Searches conducted. We included three new trials and performed new analyses (Anil 2010; Grewal 2009; Luo 2010). Our conclusions remain unchanged.
13 May 2009	Amended	No changes; republished to fix technical problem.
18 February 2008	Amended	Converted to new review format.
13 November 2007	New search has been performed	Searches conducted.