New study reevaluates aspartame as a safe sweetener

A new study has reviewed evidence in animals and humans about the health effects and safety of the low-calorie sweetener aspartame at currently accepted dosage and at higher dosage.
Previous research suggest artificial sweeteners like aspartame can help weight loss and may benefit people with type 2 diabetes as they’ve been deemed as good or even superior to water for blood sugar control.
However, researchers have long debated both its recommended safe dosage (40 mg per kg of bodyweight per day) and its potential adverse effects.
In this new paper, researchers from the University of Pretoria and Stellenbosch University, in South African, have reviewed both animal and human aspartame trials published in the last ten years or so.
Many of these earlier studies concluded that aspartame consumption was not a concern at acceptable daily intake (ADI) levels, especially based on current use levels which equate to about 15 per cent of the ADI for the average adult.
To put this into perspective, given that a can of diet coke has 125mg of aspartamen, someone who weighs 150 pounds would have to drink 21.8 cans of the drink daily before going over the safe consumption level.
Yet there are several points of potential danger that the authors of the current research are still concerned about.
Although the data has been controversial and inconsistent, aspartame may modulate brain neurotransmitters such as dopamine and serotoni, and be neurotoxic because of one of its byproducts (phenylalanine) crossing the blood-brain barrier fairly easily.
Researchers also suggest that, when consumed in quantities higher than the ADI or within safe levels, aspartame can increase oxidative stress and inflammation in many different cell types and tissues.
These “pro-inflammatory” effects and associated damage were observed in blood cells, liver cells, the kidneys, the heart and the brain, although the strength of evidence varies and proof of this comes mostly from experiments in rats.
Furthermore, when aspartame gets metabolised by enzymes in our gut, resulting microbiota alterations have been linked to elevated fasting blood sugars and impaired glucose tolerance. This was again more evident in mice.
Overall, these results call for further investigation in humans as they suggest that aspartamen, even at recommended safe dosages, might not be safe when consumed over time.
The findings were published in the journal Nutrition Reviews, which is part of Oxford University Press.