Aspartame 

Aspartame, discovered in 1965, sweetens an estimated 6,000+ consumer products—from diet sodas (e.g., Diet Coke, Sprite Zero) and sugar-free gum (“Extra”, “Orbit”)

to tabletop packets (“Equal”, “NutraSweet”) and some pharmaceuticals.

This level of penetration means almost every household exposed, prompting health experts to reassess whether it's the “lesser evil” they once hoped it would be.

 

Latest Cardiovascular Alert: Blood Vessel Damage?

A new high-profile study from Karolinska Institutet (published Feb 19, 2025 in Cell Metabolism) revealed that mice on a high-fat diet with 0.15% aspartame developed significant atherosclerosis, driven by elevated insulin and a pro-inflammatory chemokine CX3CL1. Similar insulin spikes occurred in monkeys. Researchers warn these plaque-forming mechanisms may also occur in humans, but note that ApoE knockout mice are particularly vulnerable—so real-world impact remains unknown .

Mixed reactions:

• Prof. James Leiper (British Heart Foundation): The mouse results don’t prove human risk, but confirm the need for clinical trials.

• Prof. Oliver Jones (RMIT): Even if human risk exists, it’s likely small compared to high-fat diets and inactivity.

 

Cancer Concern Revisits

In 2023, WHO/IARC placed aspartame in Group 2B (“possibly carcinogenic”), citing limited evidence, particularly from liver cancer studies.
Epidemiological findings remain inconsistent, though WHO now advises against using low- and no-calorie sweeteners for long-term weight control, citing potential downsides including cardiovascular and metabolic disease.

Brain, Mood & Memory: A Silent Risk?

While evidence is sparse, animal studies link low-dose aspartame consumption to memory impairment and mood changes—and even changes passing across generations .
A couple small human trials suggest increases in irritability or depressive symptoms at high intake levels, though designs were short-term and underpowered .

Gut Microbiome Undermined

Although aspartame is absorbed early in digestion, upcoming microbiome studies are emerging. Cedars-Sinai reported altered duodenal and stool microbiota—even in humans—among frequent aspartame users, with elevated inflammatory indicators like IL-6 and TNF-α cedars-sinai.org.
Systematic reviews caution that such microbial shifts may trigger metabolic or immune dysregulation .

Research

Sweetener aspartame aggravates atherosclerosis through insulin-triggered inflammation

Wu et al., Cell Metabolism, Feb 19 2025

 

Consumption of 0.15% aspartame significantly increased insulin secretion in mice and monkeys. In ApoE⁻/⁻ mice, aspartame exacerbated atherosclerotic plaque formation through an insulin-dependent mechanism. Elevated endothelial CX3CL1 expression was implicated; deleting its receptor (Cx3cr1) in monocytes abolished plaque development. This provides a molecular link between artificial sweetener, insulin-induced inflammation, and cardiovascular disease.