Background
Aspartame is a commonly used intense artificial sweetener, being approximately 200 times
sweeter than sucrose. There have been concerns over aspartame since approval in the
1980s including a large anecdotal database reporting severe symptoms. The objective of
this study was to compare the acute symptom effects of aspartame to a control preparation.
Methods
This was a double-blind randomized cross over study conducted in a clinical research unit
in United Kingdom. Forty-eight individual who has self reported sensitivity to aspartame
were compared to 48 age and gender matched aspartame non-sensitive individuals. They
were given aspartame (100mg)-containing or control snack bars randomly at least 7 days
apart. The main outcome measures were acute effects of aspartame measured using repeated
ratings of 14 symptoms, biochemistry and metabonomics.
Results
Aspartame sensitive and non-sensitive participants differed psychologically at baseline in
handling feelings and perceived stress. Sensitive participants had higher triglycerides (2.05
± 1.44 vs. 1.26 ± 0.84mmol/L; p value 0.008) and lower HDL-C (1.16 ± 0.34 vs. 1.35 ± 0.54
mmol/L; p value 0.04), reflected in 1
H NMR serum analysis that showed differences in the
baseline lipid content between the two groups. Urine metabonomic studies showed no significant
differences. None of the rated symptoms differed between aspartame and control
bars, or between sensitive and control participants. However, aspartame sensitive participants
rated more symptoms particularly in the first test session, whether this was placebo or control. Aspartame and control bars affected GLP-1, GIP, tyrosine and phenylalanine levels
equally in both aspartame sensitive and non-sensitive subjects.
Conclusion
Using a comprehensive battery of psychological tests, biochemistry and state of the art
metabonomics there was no evidence of any acute adverse responses to aspartame. This
independent study gives reassurance to both regulatory bodies and the public that acute ingestion
of aspartame does not have any detectable psychological or metabolic effects
in humans.