Die langfristige Einnahme von Aspartam wirkt sich auf die Gehirn- und Herzfunktion aus: Wissenschaftler setzten Mäuse über ein Jahr hinweg 7 mg/kg Körpergewicht im menschlichen Äquivalent aus – 1/6 der empfohlenen Tagesdosis. Aspartam reduzierte die Fettablagerungen bei Mäusen, allerdings auf Kosten einer Herzhypertrophie und einer verminderten kognitiven Leistungsfähigkeit.

I’ve linked to the news release in the post above. In this comment, for those interested, here’s the link to the peer reviewed journal article:

https://www.sciencedirect.com/science/article/pii/S0753332225010856

From the linked article:

Long-term aspartame intake sabotages brain and heart function

In the first long-term and real-world reflective study of its kind, scientists have uncovered new detrimental health impacts of the artificial sweetener aspartame that echoes those found in shorter research.

While aspartame is one of the most studied food additives on the planet, short studies can show mechanistic impacts of aspartame but not long-term effects – and this is one reason why bodies like the World Health Organization (WHO), despite classing aspartame as “possibly carcinogenic to humans” in 2023, and the US Food and Drug Administration (FDA) have deemed it safe when consumed below the ADI threshold.

Here, the team exposed mice to 7 mg/kg (3.17 mg/lb) of body weight in human equivalent – around one-sixth of the maximum recommended daily intake – over the period of a year. Eighteen mice were given aspartame for three days every two weeks, alongside a no-dose control group of 14 animals.

Over the course of the year-long experiment, the most significant changes were seen in how the brain processed energy. Using FDG-PET imaging, the researchers tracked glucose uptake across the whole brain as well as specific regions, and found that after only two months of intermittent aspartame intake, the mice had sharp rises here – roughly double that seen in the control group. And this effect was across the entire brain, suggesting it was burning more fuel in the early stages of the experiment. However, at around six months, this spike actually reversed, and at the 10-month mark, the brains of the aspartame-dosed mice were burning around 50% less glucose than the control group. Because the brain runs almost entirely on glucose – to fuel processes like the firing of neurons and maintaining circuits linked to memory and learning – aspartame appeared to be robbing the organ of what it needs to function smoothly.

In real-world terms, aspartame appeared to cause the brain to shift from an early state of heightened energy use to a more chronic state of underuse – which is a pattern often associated with metabolic strain, not adaptation.

Looking at things on a biochemical level, the researchers used magnetic resonance spectroscopy to examine metabolites in the cerebral cortex. Again, after two months, levels of N-acetylaspartate (NAA) – a marker of neuronal metabolism and function – were about 13% higher in the aspartame group. However, by four months, early positives again vanished and continued to worsen. At eight months, lactate levels were around 2.5 times higher in aspartame-treated mice, suggesting cellular dysfunction.

When the researchers conducted spatial learning and memory tests using the Barnes maze, the aspartame mice at four months consistently moved more slowly and covered less distance during training than animals in the control group. They also took nearly twice as long on average to locate the target escape hole, showing impaired memory recall (however, this was inconsistent and not seen as statistically meaningful). By eight months, performance gaps widened even further, with two out of six aspartame-treated mice failing to complete the task at all.

Overall, long-term aspartame intake appeared to hamper the animals‘ ability to follow through with problem-solving tasks, in line with the metabolic changes that the researchers had uncovered in the brain.

But it wasn’t just the brain that was affected. Cardiac imaging revealed significant changes in heart structure and function by the end of the study. The hearts of aspartame-treated mice didn’t pump as efficiently – the chambers emptied less completely and delivered less blood with each beat, even though there was little structural damage. Over time, that means organs – including the brain – received slightly less blood and oxygen.

The researchers also found that while aspartame-treated mice accumulated about 20% less total body fat than the control animals over the 12 months, this reduction didn’t translate into improved metabolic health. Despite similar body weights, fat distribution shifted over time, with a greater proportion of fat stored viscerally around the organs and less lean mass overall. This type of fat redistribution is known to place greater strain on the heart and metabolism, helping explain why reduced fat mass in these mice coincided with changes to the heart and brain energy use.

„Aspartame does indeed reduce fat deposits (by 20%) in mice, but it does so at the cost of mild cardiac hypertrophy and decreased cognitive performance,“ the researchers confirmed. „Although this sweetener may help achieve weight loss in mice, it is accompanied by pathophysiological changes in the heart and, possibly, in the brain.“

The real question with all these things though are the risks anywhere comparable to if you just had been consuming sugar.

Like it’s reasonable to study these things but the simple fact is that overuse of sugar is demonstrably one of the more deadly things to human health so the bar for damaging side effects has to be very high.

Being fat may also decreases your cognitive performance (not exercising certainly does and obesity is associated with cognitive diseases) and it certainly causes many cardiac issues.

Much like where people are finding minor problems with GLP-1 drugs and then flipping out online I often think comparative harm reduction needs to better considered. Obesity is as dangerous if not moreso then being a heavy smoker or drug user. Losing 20 kilos would so vastly improved your health and quality of life as to outstrip any side effects.

Isn’t this why Tab soda was removed from the market?

So you can get slim AND stupid at the same time? Finally.

Okay, repeat the study with pigs. As I am reminded every time a cancer cure is found in mice, mice are vastly different than humans.

7mg/kg of aspartame is roughly 2-3 cans of diet soda for a person of 60~80 kg (130~180 lbs), in case anyone read the title and had trouble visualizing what that amount actually is.