A recent Chinese study has uncovered a concerning relationship between aspartame, a widely-used artificial sweetener, and glioblastoma, the most aggressive form of primary brain cancer, according to News Medical. The research, featured in Scientific Reports, employed mouse models to examine precisely what alterations aspartame triggered in gut bacteria and how this impacted glioblastoma development.

Scientists found that aspartame might create optimal gut conditions to promote tumour growth. In particular, higher aspartame intake led to reduced levels of Rikenellaceae family bacteria in the gut. Levels of this bacteria in the gut have previously been linked to various health issues, ranging from obesity to Parkinson’s disease and HIV.

The new study also established a connection between aspartame consumption and gene regulation within glioblastoma tumours.

The researchers said: “Our findings not only provide critical evidence for evaluating the safety of artificial sweeteners but also offer a comprehensive assessment of their impact on tumor progression.

“These insights open new avenues for GBM treatment strategies, including gene-targeted therapies and microbial-based interventions, among others.”

The scientists intend to continue their investigation into how aspartame-triggered modifications affect metabolism and tumour environments. 

A past joint report, which included organisations such as the International Agency for Research on Cancer, labelled aspartame as ‘possibly carcinogenic’. This means it could potentially cause cancer in humans, but the evidence is not conclusive.

The report stated that the acceptable daily intake of aspartame is capped at 40mg per kilogram of body weight. So, if you weigh 80kg, your daily aspartame limit should be 3.2g.

While this might seem like a large amount, aspartame is found in numerous everyday products, especially those marketed as ‘diet’ or sugar-free. Some fizzy drinks can contain up to 200mg of aspartame in just one can.

Aspartame can also be found in a variety of other items, including medications and chewable vitamins. Experts at ZOE noted that it’s approximately 200 times sweeter than sugar.

Despite being deemed safe by global regulatory bodies, scientists have been raising concerns about aspartame in studies for years.

However, a 2019 review of these studies in the BMJ concluded there were no significant health risks or benefits associated with artificial sweeteners, largely because most studies had a small number of participants, were short-term, or were of limited quality.

A 2022 World Health Organisation review similarly noted: “There is (a) suggestion of negative health effects with long-term use, but the evidence is ultimately inconclusive.”

The ‘negative health effects’ mentioned in the review spanned concerns like obesity, type two diabetes, cardiovascular disease and even mortality.

ZOE experts shared some words of hope though: “Entirely avoiding aspartame would be incredibly challenging, and it might not be necessary. A diet with a wide variety of plant-based foods is the healthiest choice.

“And it’s less healthy to consume high amounts of ultra-processed foods, which are more likely to contain aspartame. So, whenever you can, opt for fresh ingredients, fruits and vegetables, pulses, nuts, seeds, and the like.

“Aim to have 30 different plant foods each week. That way, your intake of ultra-processed foods, and therefore aspartame, will naturally decline.”