Epilepsy and Seizures

By the Calorie Control Editorial Team

The claim that aspartame is associated with an increased risk of epilepsy is based on the anecdotal reports of individuals who happened to experience their first seizure soon after consuming an aspartame-containing food or beverage. This is not evidence of causation, but a temporal relationship between the widespread consumption of aspartame and the prevalence of epilepsy. Epileptogenesis can be promoted by a variety of factors including stress, hydration, changes in plasma osmolarity and toxic metabolites resulting from hepatic or renal overload. Administration of large doses of water alone can predispose a person to seizures. The sharing on the Internet of the misinterpreted cause of a seizure episode or epilepsy due to aspartame, and inappropriate advice to avoid it, puts affected individuals at risk if they do not seek medical attention.

Studies say “No”
The U.S. Food and Drug Administration (FDA) monitors complaints about aspartame from consumers and health professionals as part of its Adverse Reaction Monitoring System (ARMS). According to Toffleson (1993), this is a passive surveillance system based primarily on consumer-initiated reports and cannot be considered representative of the entire population. At least 50% of the reported epileptic seizures in the ARMS database had no relationship to aspartame and challenge tests among those reporting an association did not support their claims.   Assertions of the possible epileptogenesis of aspartame due to a buildup of phenylalanine in the brain can only be proven through controlled scientific studies and to date, causality has not been confirmed. Studies say “No”.

A review of studies by Butchko et al. on the effects of phenylalanine and aspartame in nine seizure models, ranging from chemical to genetic models including rodents and primates, found dosage levels below 1,000 mg/kg did not have effects on seizure susceptibility in animals. That is equivalent to an oral bolus of 18 cans of aspartame-sweetened diet soda by a 70 kg man. Results from dosage levels of aspartame at 1,000 mg/kg were inconsistent between laboratories, different seizure models and animals, showing either no effect or a proconvulsant effect. The data from these excessive bolus doses of aspartame in rodents do not suggest relevant risk to people since it is not possible for a person to orally ingest sufficient amounts of any aspartame-containing food or beverage to reach equivalent doses or raise plasma phenylalanine concentrations to comparable levels.

Consumers who believe they may have had an aspartame-related seizure or onset of epilepsy can be referred to this statement from The Epilepsy Institute published in the Congressional Record on June 20, 1986:

“As an organization devoted to people with seizure-related problems, we [at] the Epilepsy Institute have evaluated the current scientific evidence and found aspartame to be safe for people with epilepsy. . . . the members of the Professional Advisory Board of the Epilepsy Institute looked at the seizure activity of our patients, many of whom consume aspartame regularly, and saw no change over the past three years.”

Cited References

Butchko HH, et al. Aspartame: Review of Safety. Regul Toxicol Pharmacol. 2002;35(2 Pt 2):S1-93 https://www.ncbi.nlm.nih.gov/pubmed/12180494

Goldberg EM and Coulter DA. Mechanisms of epileptogenesis: a convergence on neural circuit dysfunction. Nat Rev Neurosci. 2013 May; 14(5): 337–349. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3982383/.

Sze PY. Pharmacological effects of phenylalanine on seizure susceptibility: an overview. Neurochem Res. 1989;14(2):103-111 https://www.ncbi.nlm.nih.gov/pubmed/2657469

Tollefson L. Multiple chemical sensitivity: controlled scientific studies as proof of causationRegul Toxicol Pharmacol. 1993 Aug;18(1):32-43 https://www.ncbi.nlm.nih.gov/pubmed/8234917

U.S. Government Printing Office. Congressional Record Extension of Remarks. June 20, 1986 to July 14, 1986; Vol.132(Part 11):14862 https://www.gpo.gov/fdsys/pkg/GPO-CRECB-1986-pt11/pdf/GPO-CRECB-1986-pt11-1-2.pdf

Items of Interest

February 13, 2017 Claims & Myths