Potential Association of Aspartame with MS Relapse

Background: While the cause of multiple sclerosis (MS) is unknown, the consensus is that it is an immune-mediated disease affecting the central nervous system through interaction between genetic predisposition and environmental factors. 

Objectives: Present a case in which aspartame exposure is temporally associated with MS relapse with significant inflammation on brain MRI.

Methods: Clinical and radiographic correlation of a patient presenting with an MS relapse.

Results: A thirty-five year-old female with a thirteen year history of relapsing-remitting MS presented with a relapse, including symptoms of right-sided numbness, falls/imbalance, poor spatial awareness, and anxiety/rage. She abstained from sugar for two weeks, heavily substituting aspartame as a sweetener before discontinuing aspartame due to neurologic symptom onset. She previously had six relapses over the first eleven years of MS, with resolution of symptoms after each episode. Exam revealed mild right interosseous and right iliopsoas weakness. The remainder of the neurologic exam was normal. Brain MRI demonstrated four active lesions. Brain MRI studies six months prior, two months after, and twenty months after the relapse were stable in lesion burden and were inactive.  She was on weekly beta-interferon-1a; neutralizing antibodies were negative after the relapse.  Her neurologic symptoms resolved after approximately one month.

Conclusions: This case may represent aspartame influencing inflammation in a human with MS.  The literature on aspartame studies in animal models and humans is discussed.  The literature has conflicting points of view.