Are Artificial Sweeteners Aging Your Brain?
For decades, low- and no-calorie sweeteners have been marketed as a smarter alternative to sugar — a way to cut calories without sacrificing taste. But new research published in Neurology suggests the story may be more complicated.
According to an eight-year study tracking more than 12,000 adults, heavy consumption of popular sugar substitutes was linked to significantly faster cognitive decline.
What the Study Found
Researchers followed participants over nearly a decade, regularly assessing memory, word recall, and processing speed. Those who consumed the highest amounts of artificial sweeteners — roughly the equivalent of one diet soda per day — experienced cognitive decline at a rate 62% faster than those with the lowest intake.
In practical terms, the drop in brain performance resembled about 1.6 extra years of biological aging.
The most pronounced effects appeared in adults under 60 and in people living with diabetes — two groups that often rely on sugar substitutes such as aspartame, saccharine, and erythritol to manage calorie or glucose intake.
Interestingly, tagatose was the only sweetener not linked to negative cognitive outcomes in this study.
Why It Matters
Artificial sweeteners are common in ultra-processed foods, including diet sodas, “light” yogurts, protein bars, and energy drinks. Many consumers choose these products believing they are making a brain-healthy swap by avoiding sugar. However, this research raises the possibility that long-term, high intake of certain substitutes may carry its own neurological costs.
The researchers emphasize that the findings show an association, not proof of direct causation. That means artificial sweeteners were linked to faster cognitive decline, but the study does not prove they directly cause it. Other lifestyle or dietary factors could also play a role.
A Cautious Takeaway
While this study does not suggest panic or immediate elimination of all sugar substitutes, it does challenge the assumption that “diet” automatically means healthier — especially for long-term brain health.
Moderation appears key. For individuals regularly consuming artificially sweetened products, it may be worth reassessing overall dietary patterns rather than focusing solely on calorie reduction.
As research continues to explore the connection between nutrition and cognitive aging, one message is becoming clearer: when it comes to the brain, there may be no shortcut around balanced, minimally processed foods.
Source:
Gonçalves, N. G., Martinez-Steele, E., Lotufo, P. A., et al. (2025). Association Between Consumption of Low- and No-Calorie Artificial Sweeteners and Cognitive Decline: An 8-Year Prospective Study. Neurology.
About the author John O’Sullivan is CEO and co-founder (with Dr Tim Ball among 45 scientists) of Principia Scientific International (PSI). He is a seasoned science writer, retired teacher and legal analyst who assisted skeptic climatologist Dr Ball in defeating UN climate expert, Michael ‘hockey stick’ Mann in the multi-million-dollar ‘science trial of the century‘. From 2010 O’Sullivan led the original ‘Slayers’ group of scientists who compiled the book ‘Slaying the Sky Dragon: Death of the Greenhouse Gas Theory’ debunking alarmist lies about carbon dioxide plus their follow-up climate book. His most recent publication, ‘Slaying the Virus and Vaccine Dragon’ broadens PSI’s critiques of mainstream medical group think and junk science.
Anapat
| #
I suspect it’s not just brain decline, but also kidney decline. A friend of mine drank diet soda instead of water throughout his life and ended up needing dialysis.
Reply