Me, being my skeptical self, looked up aspartame online and found a number of sites that also expressed skepticism at such a claim.  As I dug deeper, however, I found a consistent pattern of information from a growing number of individuals and groups expressing concern about aspartame.

Aspartame is a food additive used in all types of food as a sweetener.  It is quite difficult to find gum or mints that do not have aspartame in them.  Sweeteners such as Equal are made from aspartame.

The Ecologist online had this to offer:

Because it contains no calories, aspartame is considered a boon to health-conscious individuals everywhere; and most of us, if we think about it at all, think it is safe. But independent scientists say aspartame can produce a range of disturbing adverse effects in humans, including headaches, memory loss, mood swings, seizures, multiple sclerosis and Parkinson's-like symptoms, tumours and even death.

I found a site that recommended a documentary named Sweet Misery: A Poisoned World and I watched it with my family via Netflix.  It was disconcerting to say the least.  The end result is that my family is actively searching for products in our home that contain aspartame so we can remove them... permanently.