Sweeteners found in yoghurts and fizzy drinks can damage people’s ability to think and remember, and appear to cause “long-term harm” to health, research has found.
People who consumed the largest amount of sweeteners such as aspartame and saccharin saw a 62% faster decline in their cognitive powers – the equivalent to their having aged 1.6 years, researchers say.
They concluded: “Our findings suggest the possibility of long-term harm from low- and no-calorie sweeteners (LNCs) consumption, particularly artificial LNCs and sugar alcohols, on cognitive function.”
The findings are the latest to warn about the dangers posed by sweeteners. Previous studies have suggested they may increase the risk of a range of diseases including type 2 diabetes, cancer, heart problems, depression and dementia, and damage the gut wall.
Sweeteners’ association with cognitive decline is of such concern that consumers should instead use either tagatose, a natural sweetener, or alternatives such as honey or maple syrup, the researchers said.
They looked at the impact of seven sweeteners on the health of the study’s participants – 12,772 civil servants in Brazil, with an average age of 52 – who were followed up for on average eight years. Participants completed questionnaires detailing their food and drink intake over the previous year, and later underwent tests of their cognitive skills such as verbal fluency and word recall.
People who consumed the most sweeteners experienced declines in their thinking and memory skills 62% faster than those with the lowest intake, the researchers found. This was “the equivalent of about 1.6 years of ageing”, the researchers said.
Consumption of combined and individual LNCs, particularly aspartame, saccharin, acesulfame K, erythritol, sorbitol and xylitol, was associated with cognitive loss.
“Daily consumption of LNCs was associated with accelerated decline in memory, verbal fluency and global cognition,” the authors say in their paper, published in the American medical journal Neurology.
However, the trend was only observed in participants under the age of 60. That shows that middle-aged adults need to be encouraged to use fewer sweeteners, they added.
The sweeteners studied are also found in flavoured water, low-calorie desserts and energy drinks.
“Low and no-calorie sweeteners are often seen as a healthy alternative to sugar. However, our findings suggest certain sweeteners may have negative effects on brain health over time,” said Claudia Kimie Suemoto, of the University of São Paulo in Brazil, the study’s lead author.
Food and drink industry bodies cast doubt on the findings. “By the authors’ own admission, this study cannot prove cause,” said Gavin Partington, the director general of the British Soft Drinks Association.
“Non-sugar sweeteners are safe, according to all leading health authorities in the world, and that’s why they have been used in a vast array of food, medicine, dental and drinks products for many decades.
“Their use in soft drinks has helped UK manufacturers to remove just under three-quarters of a billion kilograms of sugar from product since 2015.”
The International Sweeteners Association (ISA) said there was an “established scientific consensus” that sweeteners are safe.
“This research is an observational study, which can only show a statistical association, not a direct cause-and-effect relationship,” the ISA said in a statement. “The reported link between sweetener consumption and cognitive decline does not prove that one causes the other.”
