An artificial sweetener that can cause irreversible damage to your brain and body

Nutrition Research Newsletter, May, 2008

From a global perspective, people are conscious about their health. Artificial sweeteners are used as a substitute to sugar as they are sweet to taste and low in calories. Artificial sweeteners are used by diabetics and by people who are under a weight loss regimen. Aspartame, an artificial sweetener is commonly used by people, because it has all the qualities that an artificial sweetener ought to have. But, is aspartame good for one's health and brain? The study carried out by Humphries, Pretorius and their colleagues from South Africa ascertains the deleterious effects caused by the various elements (phenylalanine, aspartic acid and methanol) of aspartame on the brain.

One of the objectives behind this review-based study of previously published articles was to determine the deleterious effects of aspartame and its breakdown products on the brain and the neurotransmitters. Aspartame is a combination of 50% of phenylalanine, 40% of aspartic acid, and 10% methanol.

Phenylalanine (a component of aspartame) is known to regulate neurotransmitters. The study highlights the possible adverse effects of phenylalanine wherein it disrupts the chemical makeup of the brain and also lowers the levels of serotonin, a neurotransmitter, which in turn affects its functions such as sleep, appetite, mood, and behavior. Phenylalanine also disrupts amino acid metabolism, hormonal equilibrium, and nerve functions. Aspartic acid is believed to function as an excitatory neurotransmitter in the central nervous system (CNS). Methanol gets converted to formate, it is either excreted or it gets accumulated in the body to form formaldehyde, diketopiperazine (a carcinogen) and other potent toxic products. Aspartame consumption can disrupt amino acid metabolism, protein structure and metabolism, nucleic acid integrity, neuronal functions, and hormonal equilibrium. It can also cause improper functioning of enzymes, depletes the cells' adenosine triphosphate (ATP) stores and this in turn lowers the glucose levels, thereby indirectly hindering the synthesis of acetylcholine and glutamate. Aspartame also disrupts the uptake of calcium, thus the function of glutamate as a neurotransmitter is inhibited.

Studies that were conducted earlier believe that aspartame can cause neurological problems such as headaches, insomnia, and seizures, and these can be attributed to the imbalance of the brain's chemical concentrations namely, norepinephrine, epinephrine, and dopamine. Aspartame is also found to cause certain behavioral disturbances. Long-term consumption of subtoxic levels of aspartame is harmful because the by-products of aspartame accumulate in the tissues (Trocho et al, 1998). An animal model study conducted in the year 2007 by Humphries and his colleagues showed that aspartame affects the morphology of the fibrin network, platelets aggregation and some organs.

Thus, the review-based study concludes that aspartame affects the direct and indirect cellular activities of the brain. Therefore, excessive consumption of the same can lead to mental and emotional disturbances and can also hinder learning abilities. According to Humphries, extensive studies are required in the future to ascertain the detrimental effects of aspartame on the microscopic structure of various body organs.

The National Research Foundation (NRF) funded Pretorius for this study.

Humphries P., Pretorius E., and Naude H. Direct and Indirect Cellular of Aspartame on the Brain. European Journal of Clinical Nutrition; 62(4):451-62 (April 2008). [Correspondence: Petro Humphries, Department of Anatomy, University of Limpopo, Medunsa Campus, PO Box 232, Medunsa 0204, South Africa. E-mail: humphries@medunsa.ac.za.]