Aspartame, a carcinogen?

In my previous blog post, I introduced many sugars and their substitutes. One of the sugar substitutes was aspartame. Aspartame is a sugar substitute found in diet coke and was declared a possible carcinogen this month by the World Health Organisation International Agency for Research on Cancer (IARC).

According to the article released by the World Health Organisation (WHO), aspartame was classified as possibly carcinogenic to humans on the basis of limited evidence for cancer in humans, specifically liver cancer.

A systematic study done in 2014 has shown that metabolites of aspartame such as phenylalanine can cause DNA mutations in multiple bacteria strains. Cancer is caused by changes in the DNA which results in cells dividing uncontrollably, forming tumors. Research has also shown that exposure to aspartame has resulted in increased replications of multiple bacterial strains. In addition, numerous studies on animal models have also seen a direct relationship between aspartame exposure and cancer incidence in animal models.

However, epidemiological studies in humans showed conflicting results. The systematic study published in 2014 found that only 2 out of 6 studies reflected a positive correlation between aspartame exposure and cancer incidence. One study did not show a correlation in females but a positive correlation among males.

As there were more studies proving a direct relationship between aspartame and cancer, it was concluded that aspartame was a likely carcinogen.

The WHO expert committee on food additives states that the acceptable daily intake of aspartame should be 40mg per kg of body weight, which corresponds to 9-14 cans of diet soft drinks. This means that one can still drink diet coke, just in moderation.

Nature has also published articles stating that aspartame is metabolized into phenylalanine, aspartic acid, and methanol. Methanol, in particular, is known to be carcinogenic as it can be further broken down into formic acid in the body, which damages DNA.

Currently, more studies are still needed to explore aspartame’s effect on the body, as well as its link to diseases. There is still no need to ban or avoid the product entirely, although that may be set to change in the near future.

References:

Yılmaz, S., & Uçar, A. (2014). A review of the genotoxic and carcinogenic effects of aspartame: does it safe or not?. Cytotechnology, 66(6), 875–881. https://doi.org/10.1007/s10616-013-9681-0

Nature (basingstoke. online). ISSN 1476-4687 (Online) | Nature | The ISSN Portal. (n.d.). https://portal.issn.org/resource/issn/1476-4687