Lee 1999, Bjelakovic Cochrane 2008 mortality, Hennekens 1996, Lin 2009, Hercberg 2004, Lonn 2005, Bjelakovic Cochrane 2008 gastrointestinal cancers, Lippman 2009, Gaziano 2009
*patients with various dideases as gastrointestinal, cardiovascular, neurologic, ocular, dermatologic, rheumatoid, renal, endocrinologic or unspecified diseases
