Martin, There was quite a bit of list traffic on the subject of aspartame about a year or so ago. A visit to the searchable list archive maintained by Simon Cole at http://james.parkinsons.org.uk/search.htm, and a search there on aspartame could answer some of your queries. On a subjective level, I reported at the time that I experienced an improvement in both the quality and duration of my "on" periods when I cut aspartame from my diet. A year or so later I no longer have an up-front awareness of that improvement but I remain convinced that, in my case at least, aspartame exacerbates PD symptoms. A friend suggested that I should reintroduce aspartame to my diet to see if I got worse. From the point of view of science he is undoubtedly correct, and a few years ago I would have been an enthusiastic participant in the experiment, but these days I'm happy to take Khayyam's advice to "....take the cash in hand and leave the rest". Dennis..