Non-nutritive Sweeteners And The Brain
I have been trying to reduce the amount of sugar I eat and drink, but now I hear that artificial sweeteners may contribute to brain aging? Are there any good alternatives?
Andrew Weil, M.D. | March 9, 2026
You are wise to limit your sugar consumption, but there are many reasons to avoid the most commonly used sugar substitutes. Those substitutes may be artificial or natural, but they are all non-nutritive, meaning they have no carbohydrates or calories—they have no nutritional value, just sweetness. The artificial ones are especially problematic, as they not only don’t help with weight loss but have also been linked to higher risks of weight gain, obesity, high blood pressure, diabetes, heart disease and other health problems. Now a report links them to a decline in brain health as well.
The study you may have heard about was conducted over an eight-year period and included nearly 13,000 people. For those under age 60, the group that consumed the most aspartame, saccharin, acesulfame k, erythritol, sorbitol, and xylitol showed the greatest cognitive decline over the study period. The manifestations of the decline were different in participants with diabetes compared to those without diabetes, but both sub-groups showed cognitive decline.
Surprisingly, participants age 60 and over did not show the same trend in this study, although I don’t interpret that to mean that non-nutritive sweeteners are okay for older people. And I am generally cautious about studies that rely on self-reported data, such as this one. Still, I find this to be one more data point in a large and growing body of evidence suggesting that non-nutritive sweeteners are best avoided.
Before you go back to using table sugar (sucrose), however, I’ll point out that a 2023 review of 77 different studies that analyzed data on over 17,000 participants also found a correlation between cognitive decline and high consumption of sugar. Sucrose is a compound of fructose and glucose, which the body breaks down into those two components during digestion. Glucose delivers a quick boost to insulin levels; fructose raises insulin more slowly but has been associated with liver dysfunction, metabolic syndrome, increased levels of serum triglycerides, and promotion of obesity.
I strongly advise limiting consumption of fructose, which is especially high in honey and agave syrup. My preferred sweetener is maple syrup; it has a lower fructose content than table sugar. For those with diabetes, the only sugar substitutes I would recommend are tagatose, monk fruit, and stevia.
In general, though, I recommend limiting sweet treats—when I want something sweet, I try to stick to dark chocolate, with at least 70 percent cocoa. (See my video What to Eat When You Crave Sweets for more details.)
Andrew Weil, M.D.
Sources
Gonçalves NG, Martinez-Steele E, Lotufo PA, Bensenor I, Goulart AC, Barreto SM, Giatti L, de Faria CP, Molina MDCB, Caramelli P, Marchioni DM, Suemoto CK. “Association Between Consumption of Low- and No-Calorie Artificial Sweeteners and Cognitive Decline: An 8-Year Prospective Study.” Neurology. 2025 Oct 7;105(7):e214023. doi: 10.1212/WNL.0000000000214023. Epub 2025 Sep 3. Erratum in: Neurology. 2025 Dec 9;105(11):e214393. doi: 10.1212/WNL.0000000000214393. PMID: 40902134. pubmed.ncbi.nlm.nih/40902134/
Gillespie KM, White MJ, Kemps E, Moore H, Dymond A, Bartlett SE. “The Impact of Free and Added Sugars on Cognitive Function: A Systematic Review and Meta-Analysis.” Nutrients. 2023 Dec 25;16(1):75. doi: 10.3390/nu16010075. PMID: 38201905; PMCID: PMC10780393. pubmed.ncbi.nlm.nih/38201905/
