CASE STUDY – December 2001
[A major newspaper in Norway]
Introduction: Aspartame (ASM) is a product that was originally made for diabetics, but today ASM is widely used by healthy people as an artificial sweetener in many food products.
Purpose: The main goal with this research was to see whether ASM was harmful to brain cells (cerebellar granule cells). We wanted to check if the damage to the neurons is connected to the N-methyl-D-aspartate (NMDA)-receptors on these cells.
Procedure: Brain cells from 7 day old mice were used. They were cultured in 24 Petri well dishes, and different quantities of ASM were added. After 7 days, the cultures were analysed by two different tests: Lactate dehydrogenases (LDH) test, which gives a picture of cell death (LDH leakage to the medium in which the cells were cultured). 3-[4,5-dimethylthiazol-2yl]-2,5-diphenyltetrazolium bromid (MTT) test, which can be used to analyse mitochondrial activity in living cells. To test whether the NMDA-receptor was involved in the damage done by ASM, the receptor was blocked by (±)-2-amino-5 phosphonopentanocid (AP5).
Results: Our results showed damage/cell death from an added quantity of 0.06 mg/ml ASM each day for 4 days. As a comparison there is 0.24 mg/ml ASM in Cola Light. MTT- and LDH-tests showed damage to the neurons at an added quantity of 1.5 and 3.00 mg/ml ASM after 22 hours of incubation. The results also show that ASM is in part acting through the NMDA-receptor because AP5 reduced or blocked the damage to the granule cells.
Conclusion: In light of these results, our conclusion is that in order to be on the safe side, it should be warned against use of ASM as a food additive, maybe especially in products consumed by children, because NMDA-receptors and the synapses involved also are connected to learning.