Sweetener safety – summary
- Sweeteners widely used across food products now face growing scientific scrutiny
- New Brazilian study links higher sweetener intake with faster cognitive decline
- Several sweeteners associated with reduced memory and verbal fluency performance
- Younger adults and people with diabetes show stronger negative cognitive impacts
- Manufacturers may face rising pressure as trust falls and research intensifies
Sweeteners are found in literally thousands of food and beverage products – from chocolates and ice creams right through to breakfast cereals and breads. In fact, it’s hard to think of a single category that doesn’t rely on them in one form or another.
Whether it’s to reduce sugar content, boost flavour, balance acidity, improve texture, enhance mouthfeel or extend shelf life, sweeteners have become essential to modern food and beverage formulation.
But, while industry celebrates them as the perfect fix to so many challenges, scientists urge caution.
In recent years, we’ve seen xylitol linked to an increased risk of heart attack and stroke, neotame linked to gut damage, sucralose linked to increased appetite, and multiple sweeteners linked to early onset puberty.
It’s little wonder then that many consumers are moving away from products containing sweeteners.
And things are about to get worse, as a new study out of Brazil is linking them to cognitive decline.
Do sweeteners damage brain health?
A new study, conducted by scientists at the University of São Paulo, has analysed the impact of seven widely used sweeteners – aspartame, saccharin, acesulfame-K, erythritol, xylitol, sorbitol, and tagatose – on the brain.
And while results didn’t show that sweeteners directly damage the brain, they did highlight an “association” between the two.
“Low- and no-calorie sweeteners are often seen as a healthy alternative to sugar,” says study author Dr Claudia Kimie Suemoto. “However, our findings suggest certain sweeteners may have negative effects on brain health over time.”
To explore the long-term effects, the researchers followed 12,772 adults from across Brazil over eight years.
At the start, participants completed detailed diet questionnaires, covering what they had eaten and drunk over the previous year. They were then grouped by levels of artificial sweeteners they’d consumed.
The lowest intake group averaged 20 milligrams per day (mg/day). The highest intake group averaged 191 mg/day.
Candidates also took cognitive tests at the beginning, middle, and end of the study. These assessments tracked several skills that tend to change with ageing and brain health, including how well they processed, held, and recalled information.
After adjusting for factors such as age, sex, high blood pressure and cardiovascular disease, the researchers found that the highest intake group declined 62% faster in overall thinking and memory than the lowest intake group. The difference, they said, was comparable to around 1.6 years of ageing.
The middle intake group also declined faster than the lowest intake group, with a 35% faster drop – equivalent of around 1.3 years of ageing.
What’s more, a clear impact pattern emerged, when the data was analysed by age.
Age and health matters
Under 60s, who consumed the highest levels of sweeteners, were found to experience steeper drops in verbal fluency and overall cognitive performance compared with those who consumed the least. By contrast, no significant association was observed in over 60s.
The relationship between sweetener intake and cognitive decline was also found to be stronger in participants with diabetes, compared with those without.
Which sweeteners are worse?
Looking at individual sweeteners, higher consumption of aspartame, saccharin, acesulfame-k, erythritol, sorbitol and xylitol was linked to faster declines in overall cognitive function, especially memory.
Tagatose was the only sweetener studied that did not show an association with cognitive decline.
“While we found links to cognitive decline for middle-aged people both with and without diabetes, people with diabetes are more likely to use artificial sweeteners as sugar substitutes,” says Dr Suemoto. “More research is needed to confirm our findings and to investigate if other refined sugar alternatives, such as applesauce, honey, maple syrup, or coconut sugar, may be effective alternatives.”
The authors were quick to highlight several study limitations. First, the analysis didn’t include every type of artificial sweetener on the market. Second, dietary information was self-reported, meaning there may have been inaccuracies.
What does this mean for manufacturers?
For food and beverage makers, these findings add yet another layer of complexity to an already heated conversation.
Regulators around the world continue to deem approved sweeteners safe at current intake levels. But what’s considered safe in one region may not be in another. Some regulators take a more precautionary approach, and acceptable daily intake levels can vary as a result – adding to the confusion. Added to this, ingredients once considered uncontroversial can quickly come under new scrutiny.
This puts manufacturers in a difficult position. On the one hand, sweeteners remain valuable formulation tools – helping brands hit sugar‑reduction targets, meet HFSS regulations, and satisfy consumer expectations around taste and calorie count. On the other, growing scientific uncertainty and declining consumer trust risk undermining the very innovations these ingredients enable.
Moreover, terms like ‘clean label’ and ‘natural’ are fast becoming powerful purchasing drivers, meaning brands that rely heavily on artificial or bulk sweeteners may face a fall in sales.
In short, the sweetener debate isn’t going away. If anything, it’s just getting started.
