Study Design:
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Quality Rating:
Research Purpose:

To address the question of whether aspartame might exacerbate epilepsy in humans, 10 children with generalized absence epilepsy were studied.

Inclusion Criteria:

Newly diagnosed with generalized absence seizures.

Exclusion Criteria:

Not discussed.

Description of Study Protocol:


Consecutive newly diagnosed patients were asked if they would participate in the study.


  • Double-blind controlled study
  • Each subject received both treatments (crossover design).

Blinding Used

Subjects and study staff did not know which beverages contained aspartame and which contained sucrose.  Only the hospital pharmacy staff was un-blinded to the sweeteners used.


  • Following one hour of baseline EEG recordings, the subjects were given a 250ml unsweetened orange juice with either aspartame or sucrose added
  • The amount of aspartame added to the beverage was 40mg per kg.  The amount of sucrose was based on one gram for each 25mg aspartame
  • The children remained in the hospital during the two study days and performed similar activities each day. 

Statistical Analysis

  • Number and length of spike-wave bursts on the EEG were tabulated
  • The Wilcoxon signed-rank test was used for data analysis
  • Only non-parametric statistics were used because of the small sample size and concern that the data was not normally distributed.
Data Collection Summary:

Timing of Measurements

  • Six to eight hours of ambulatory cassette EEG recordings were done on two consecutive days
  • These measurements were done shortly after diagnosis, prior to receiving any anti-epileptic medications.

Dependent Variables

An EEG was done to measure spike waves after administration of a drink containing either sucrose or aspartame. 

Independent Variables

Consumption of either aspartame or sucrose.

Control Variables

Subjects acted as their own controls with the crossover design.

Description of Actual Data Sample:
  • Initial N: 10 (8 female)
  • Attrition (Final N): 10
  • Age: 10.3 years (range 5.1 to 14.5)
  • Ethnicity: Canadian by location
  • Location: Canada.


Summary of Results:


  • Total duration of spike wave discharge per hour significantly increased after aspartame (P=0.028) with a 40±17% SEM increase in number of seconds per hour of EEG recording that children spent in spike wave discharge
  • No significant difference between mean number of spike wave bursts for each patients before sucrose or aspartame (P=0.953)
  • Mean length of spike wave bursts after aspartame was longer than after sucrose in eight of 10 children, but difference was not significant (P=0.139).
Author Conclusion:

Aspartame appears to exacerbate the amount of EEG spike wave in children with absence seizures.  We recommend that children with poorly controlled absence seizures avoid aspartame.

Funding Source:
Foundation associated with industry:
Reviewer Comments:

Very good discussion in the paper that includes why this seizure diagnosis was used for study and why these findings may  be clinically significant.

Quality Criteria Checklist: Primary Research
Relevance Questions
  1. Would implementing the studied intervention or procedure (if found successful) result in improved outcomes for the patients/clients/population group? (Not Applicable for some epidemiological studies) Yes
  2. Did the authors study an outcome (dependent variable) or topic that the patients/clients/population group would care about? Yes
  3. Is the focus of the intervention or procedure (independent variable) or topic of study a common issue of concern to dieteticspractice? Yes
  4. Is the intervention or procedure feasible? (NA for some epidemiological studies) Yes
Validity Questions
1. Was the research question clearly stated? Yes
  1.1. Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified? Yes
  1.2. Was (were) the outcome(s) [dependent variable(s)] clearly indicated? Yes
  1.3. Were the target population and setting specified? Yes
2. Was the selection of study subjects/patients free from bias? Yes
  2.1. Were inclusion/exclusion criteria specified (e.g., risk, point in disease progression, diagnostic or prognosis criteria), and with sufficient detail and without omitting criteria critical to the study? ???
  2.2. Were criteria applied equally to all study groups? N/A
  2.3. Were health, demographics, and other characteristics of subjects described? No
  2.4. Were the subjects/patients a representative sample of the relevant population? Yes
3. Were study groups comparable? N/A
  3.1. Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT) N/A
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? N/A
  3.3. Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) N/A
  3.4. If cohort study or cross-sectional study, were groups comparable on important confounding factors and/or were preexisting differences accounted for by using appropriate adjustments in statistical analysis? N/A
  3.5. If case control study, were potential confounding factors comparable for cases and controls? (If case series or trial with subjects serving as own control, this criterion is not applicable.) N/A
  3.6. If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")? N/A
4. Was method of handling withdrawals described? ???
  4.1. Were follow-up methods described and the same for all groups? ???
  4.2. Was the number, characteristics of withdrawals (i.e., dropouts, lost to follow up, attrition rate) and/or response rate (cross-sectional studies) described for each group? (Follow up goal for a strong study is 80%.) ???
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? ???
  4.4. Were reasons for withdrawals similar across groups? ???
  4.5. If diagnostic test, was decision to perform reference test not dependent on results of test under study? N/A
5. Was blinding used to prevent introduction of bias? Yes
  5.1. In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate? Yes
  5.2. Were data collectors blinded for outcomes assessment? (If outcome is measured using an objective test, such as a lab value, this criterion is assumed to be met.) Yes
  5.3. In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded? N/A
  5.4. In case control study, was case definition explicit and case ascertainment not influenced by exposure status? N/A
  5.5. In diagnostic study, were test results blinded to patient history and other test results? N/A
6. Were intervention/therapeutic regimens/exposure factor or procedure and any comparison(s) described in detail? Were interveningfactors described? Yes
  6.1. In RCT or other intervention trial, were protocols described for all regimens studied? Yes
  6.2. In observational study, were interventions, study settings, and clinicians/provider described? N/A
  6.3. Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect? Yes
  6.4. Was the amount of exposure and, if relevant, subject/patient compliance measured? Yes
  6.5. Were co-interventions (e.g., ancillary treatments, other therapies) described? N/A
  6.6. Were extra or unplanned treatments described? Yes
  6.7. Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups? Yes
  6.8. In diagnostic study, were details of test administration and replication sufficient? N/A
7. Were outcomes clearly defined and the measurements valid and reliable? Yes
  7.1. Were primary and secondary endpoints described and relevant to the question? Yes
  7.2. Were nutrition measures appropriate to question and outcomes of concern? Yes
  7.3. Was the period of follow-up long enough for important outcome(s) to occur? Yes
  7.4. Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures? Yes
  7.5. Was the measurement of effect at an appropriate level of precision? Yes
  7.6. Were other factors accounted for (measured) that could affect outcomes? Yes
  7.7. Were the measurements conducted consistently across groups? Yes
8. Was the statistical analysis appropriate for the study design and type of outcome indicators? Yes
  8.1. Were statistical analyses adequately described and the results reported appropriately? Yes
  8.2. Were correct statistical tests used and assumptions of test not violated? Yes
  8.3. Were statistics reported with levels of significance and/or confidence intervals? Yes
  8.4. Was "intent to treat" analysis of outcomes done (and as appropriate, was there an analysis of outcomes for those maximally exposed or a dose-response analysis)? N/A
  8.5. Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)? N/A
  8.6. Was clinical significance as well as statistical significance reported? Yes
  8.7. If negative findings, was a power calculation reported to address type 2 error? Yes
9. Are conclusions supported by results with biases and limitations taken into consideration? Yes
  9.1. Is there a discussion of findings? Yes
  9.2. Are biases and study limitations identified and discussed? Yes
10. Is bias due to study's funding or sponsorship unlikely? Yes
  10.1. Were sources of funding and investigators' affiliations described? Yes
  10.2. Was the study free from apparent conflict of interest? Yes