Safety of aspartame (2014 Update)

Introduction

Aspartame is a dipeptide composed of two amino acids, phenylalanine and aspartic acid, and is used for its very sweet taste. It allows for sweet-tasting food with a much lower caloric content than sugar. It is one of the most widely used artificial sweetener and is found in a very wide range of ‘diet’ and low-calorie products. Over the years many, there have been claims on the toxicity of aspartame, in particular its carcinogenicity, and a very large number of studies evaluated in depth the safety of this food additive.

What happens to aspartame in the body?

Aspartame is rapidly and completely digested into its components, phenylalanine and aspartic acid (two amino acids that are part of natural proteins and that are found in other foods) as well as some methanol. The complete digestion of aspartame means that there is no detectable aspartame that enters the bloodstream.

Each of those breakdown products has been evaluated for its effect on human health:

Phenylalanine: it is linked with development problems in the children of mothers who, due to a genetic disorder (known as phenylketonuria, or PKU), have very high levels of phenyalanine in their bloodstream. However, the amount of phenylalanine due to aspartame consumption at the current ADI is much smaller than what would cause any health problem.

Aspartic acid: in high concentration it can affect the balance of neurotransmitters, but this concentration is never reached with eating aspartame at the current ADI.

Methanol: methanol is toxic in high concentration, but again the level at which any toxicity is seen is much higher than what is reached by the digestion of foods containing aspartame at the current ADI.

There is also no reliable evidence that links aspartame to cancer.

What is the maximum acceptable dose?

The Scientific Committee concluded that aspartame is not of safety concern at the current aspartame exposure estimates and at an Acceptable Daily Intake (ADI) of 40 mg/kg bw/day. Regarding the possible development effects related to phenylalanine, the Opinion is that, in human, the concentration reached in human serum after consumption of aspartame at the current ADI would never reach levels above recommended limits

By using the data of the industry and of food consumption surveys conducted in a number of European countries, an estimation level of exposure can be drawn up. It was found that the highest consumers ingest less than the acceptable daily dose.

Conclusion

After its re-evaluation of aspartame (E 951) as a food additive, the ANS EFSA Panel concluded that aspartame was not of safety concern related to its consumption at the current acceptable daily intake (ADI) of 40 mg/kg bw/day. Therefore, it was also concluded that there was no reason to revise this current ADI for aspartame.

People suffering from phenylketonurea (PKU), however, could be at risk since they have to limit their intake of phenylalanine. Current EU regulations already impose the labeling of any product containing aspartame as a product that contains a source of phenylalanine.