sentences:  In a rebuttal to Walton's statements, the Aspartame Information Service (a service provided by Ajinomoto, a primary producer and supplier of aspartame), reviewed the publications Walton cites as critical of aspartame, arguing that most of them do not involve aspartame or do not draw negative conclusions, are not peer-reviewed, are anecdotal, or are duplicates.An elaborate health scare, involving a hoax conspiracy theory disseminated on many websites in 1999, attributes a host of deleterious medical effects to aspartame.This theory claims that the FDA approval process of aspartame was tainted and cites as its source an email based upon a supposed talk by a "Nancy Markle" (thought to be Betty Martini, who first circulated the email) at a "World Environmental Conference."