Angels legend Garret Anderson 's cause of death has been revealed ... with officials stating the World Series champion passed away due to complications with his pancreas. The 53-year-old's tragic death was due to "acute necrotizing pancreatitis." Gallstone disease and alcohol use are the two leading factors for the complication, according to the Cleveland Clinic. As TMZ Sports previously reported, Anderson suffered a medical emergency at his home in Newport Beach, CA on Thursday ... and