Ever since the Food and Drug Administration (FDA) approved this sugar-alternative in 1981 (and then once more in 1987),[1] aspartame has been quite controversial.

So controversial, in fact, that some large, international retailers (like Woolworths and Marks & Spencer) have removed any aspartame-containing products from their product line, concerned that supplying such items would negatively affect their brand-image!

Even though aspartame has been labeled as “safe” by both the FDA and the European Food Safety Authority, it still remains a cause of concern to many people and thus warrants further scientific attention and research.

Does Aspartame Affect the Brain’s Receptors and Enzymes?

Yes. Aspartame does affect the brain. The impact is more clear in long-term studies than in short-term studies.

According to one study, published by Christian et. al. in the Journal of Pharmacology, Biochemistry and Behavior, aspartame-treated rats (ingesting 250 mg/kg/day of aspartame) had higher concentrations of muscarinic receptors in several brain regions and took longer to complete the T-Maze than the control group did after a 4 month period of aspartame administration.[2]

So, the researchers trained the two groups of rats (control and aspartame-treated) in the T-Maze 3 times per day for a period of 2 weeks. Regardless of condition, all animals were able to find the piece of chocolate (the reward) within 12 seconds time. Aspartame administration continued over the next 4 months and the animals would be tested again from time to time.