Reviewed by the Help Dementia Editorial Team — our editors review every article for accuracy against guidance from the National Institute on Aging, the Alzheimer’s Association, and peer-reviewed sources.
Mayo clinic sits at the center of this dementia and brain health question.
A new study from the Mayo Clinic has found that artificial sweeteners may be linked to faster cognitive decline in adults, raising concerns about the long-term brain health effects of these widely consumed additives. The research, published in September 2025 in the peer-reviewed journal *Neurology*, shows that people consuming the highest amounts of artificial sweeteners experienced cognitive decline approximately 62% faster than those who consumed the least—equivalent to roughly 1.6 years of accelerated aging of the brain. This finding challenges the safety profile that artificial sweeteners have enjoyed for decades, particularly among consumers who turned to them as a healthier alternative to sugar. The study analyzed data from 12,772 adults with an average age of 52 years, making it one of the largest examinations of artificial sweetener consumption and brain health to date.
Researchers tracked cognitive performance over time and found a clear dose-dependent relationship: those in the middle consumption group experienced cognitive decline 35% faster than the lowest consumers, equivalent to about 1.3 years of accelerated aging. For anyone who drinks diet soda regularly, uses artificial sweetener in their morning coffee, or regularly consumes “sugar-free” processed foods, these results warrant serious consideration about daily consumption patterns. It’s important to note that while this study shows a strong association between artificial sweetener consumption and cognitive decline, it does not prove that sweeteners directly cause dementia. The relationship could involve other factors that researchers have not yet identified. Nevertheless, the findings add to a growing body of evidence suggesting that what we once considered a safe dietary swap may carry hidden costs for brain health.
Table of Contents
- What Does the Mayo Clinic Study Actually Show About Artificial Sweeteners and Brain Function?
- The Hidden Sources of Artificial Sweeteners in Your Diet
- Age Matters: Why Younger Adults May Face Greater Cognitive Risk
- What Can You Actually Do to Reduce Your Artificial Sweetener Exposure?
- What This Study Doesn’t Tell Us and Why That Matters
- How Artificial Sweeteners Differ in Their Potential Effects
- What Comes Next for Artificial Sweetener Research and Brain Health
- Conclusion
What Does the Mayo Clinic Study Actually Show About Artificial Sweeteners and Brain Function?
The research team examined how seven different artificial sweeteners—aspartame, saccharin, acesulfame-K, erythritol, xylitol, sorbitol, and tagatose—correlated with changes in cognitive function over time. These sweeteners are ubiquitous in the modern food supply, appearing in diet sodas, flavored waters, low-calorie desserts, sugar-free yogurts, and countless other ultra-processed foods. The study‘s strength lies in its size and the diversity of sweeteners examined, providing a broader picture than previous research that focused on single additives. What makes this finding particularly striking is the age-related pattern that emerged. Participants under age 60 who consumed the highest amounts of artificial sweeteners showed notably faster declines in verbal fluency and overall cognition compared to their peers with the lowest consumption.
However, this link was not observed in people over 60, suggesting that younger brains may be more vulnerable to whatever cognitive effects these compounds produce. A 55-year-old drinking multiple diet sodas daily faces a different risk profile than a 70-year-old doing the same. The study measured cognitive decline through standardized testing, tracking how quickly participants’ mental abilities changed over the years of observation. The acceleration rates—62% faster for the highest consumers—represent a measurable, documented pattern, not a subjective impression or theoretical concern. This distinction matters because it anchors the study’s findings in objective data rather than anecdotal reports of memory problems.
The Hidden Sources of Artificial Sweeteners in Your Diet
Most people significantly underestimate how much artificial sweetener they consume because these compounds hide in foods where consumers don’t expect them. A single can of diet soda contains sweeteners, but so does the low-calorie salad dressing, the flavored zero-calorie water, the “healthy” protein bar, the reduced-sugar yogurt, and the sugar-free gum someone might chew throughout the day. When these exposures accumulate across a full day of eating, the total consumption can become substantial, even for people who consciously avoid diet sodas. The challenge with tracking artificial sweetener consumption is that manufacturers aren’t required to prominently label total daily intake in a way that helps consumers understand cumulative exposure.
Someone might know they drink one diet cola per day but fail to notice that their breakfast yogurt, their mid-morning flavored water, their afternoon diet beverage, their dinner salad dressing, and their after-dinner sugar-free dessert all contain sweeteners. Over the course of a week, this person could be consuming artificial sweeteners multiple times daily without consciously realizing it. One important limitation of the study is that it relied on food frequency questionnaires asking participants to report their consumption patterns, which can be subject to recall bias and underreporting. People often don’t remember or accurately describe what they eat and drink, especially regarding items they consume casually or don’t think of as “foods.” This doesn’t invalidate the study’s findings, but it suggests that actual consumption in high-intake groups may have been even higher than measured, or that low-intake groups may have included some unrecognized exposure.
Age Matters: Why Younger Adults May Face Greater Cognitive Risk
The observation that artificial sweetener effects appeared strongest in people under 60 opens important questions about how age influences the brain’s response to these compounds. One hypothesis is that younger brains are more metabolically active and may process or be more vulnerable to the neurological impacts of sweeteners. Alternatively, older adults may have already experienced age-related cognitive decline that masks any additional effect from sweeteners, making the sweetener effect statistically harder to detect in that age group. This age-related finding has practical implications for dietary counseling and public health messaging.
A 45-year-old who has been drinking diet sodas for twenty years and plans to continue doing so for another thirty may face a different risk calculus than a 75-year-old who has already lived through most of their cognitive aging. The Mayo Clinic study suggests that reducing artificial sweetener consumption may be especially important for middle-aged adults who are still in the window where interventions might preserve cognitive function. For families supporting aging parents or grandparents with dementia or cognitive decline, this research raises the difficult question of whether reducing artificial sweetener intake now might help prevent or slow such decline in the future. While the study offers no evidence that reducing sweetener consumption reverses existing cognitive loss, the association with faster decline suggests that prevention-focused changes could have value for those still in their cognitively healthy years.
What Can You Actually Do to Reduce Your Artificial Sweetener Exposure?
The most straightforward approach is to identify and replace the biggest sources of artificial sweeteners in your diet. For many people, this means choosing plain water, unsweetened tea, or black coffee instead of diet sodas and artificially sweetened beverages. This single swap can eliminate the largest source of exposure for many consumers and is significantly easier than trying to scrutinize every food label. A person drinking two diet colas daily could cut their artificial sweetener intake by 30-50% simply by switching beverages. The tradeoff with reducing artificial sweetener consumption is that many alternatives involve other considerations.
Returning to regular sugar comes with its own documented health risks, including weight gain, blood sugar dysregulation, and increased dementia risk through other mechanisms. Some people use honey, stevia, or monk fruit sweeteners as alternatives, though long-term safety data for these options remains limited compared to the decades of research on artificial sweeteners. Others simply accept drinks and foods without added sweetness, which many people find challenging after years of exposure to the taste. Reading food labels becomes essential for anyone seeking to significantly reduce artificial sweetener intake, though the challenge is that not all sweeteners are always clearly listed. Looking specifically for aspartame, saccharin, acesulfame-K (also labeled as Ace-K), sucralose, neotame, and sugar alcohols like erythritol, xylitol, and sorbitol can help identify hidden sources. Many “healthy” or “sugar-free” products contain multiple sweeteners combined, multiplying exposure in a single food.
What This Study Doesn’t Tell Us and Why That Matters
The most critical limitation is that this study demonstrates association, not causation. While the researchers controlled for many factors—age, education, diet quality, physical activity, and others—they cannot rule out the possibility that people who consume large amounts of artificial sweeteners differ in other ways that directly affect cognitive decline. Perhaps high consumers of artificial sweeteners also experience more stress, sleep poorly, or have undiagnosed metabolic conditions that independently drive cognitive decline. The study’s statistical controls reduce but do not eliminate this possibility. Additionally, the mechanisms by which artificial sweeteners might affect cognition remain unknown.
Do they cross the blood-brain barrier and directly affect neural function? Do they alter the gut microbiome in ways that indirectly influence brain health through metabolic pathways? Do they trigger inflammatory responses? The Mayo Clinic study establishes a pattern—higher sweetener consumption correlates with faster cognitive decline—but doesn’t explain why. Understanding the mechanism would be essential before drawing firm conclusions about causality. Another important caveat is that this study was observational, not experimental. No one was randomly assigned to drink diet sodas or avoid them. This design is appropriate for identifying patterns in large populations but is inherently less conclusive than a randomized controlled trial. Until such controlled studies exist, prudent interpretation suggests that artificial sweeteners warrant concern but not condemnation, and that dietary reduction makes sense as a precautionary measure, especially for younger adults.
How Artificial Sweeteners Differ in Their Potential Effects
The seven sweeteners examined in the study have different chemical structures and different history of safety testing, yet the study found broadly similar associations between each and cognitive decline. Aspartame has been the most extensively studied, with decades of research examining its safety, yet the Mayo Clinic study found effects comparable to those of newer sweeteners like erythritol. This uniformity across different compounds is noteworthy and suggests that the effect may not be specific to a particular sweetener’s chemical properties but rather related to something more general about artificial sweetening compounds or their metabolic effects.
Erythritol and xylitol are sugar alcohols that many people consider more “natural” because they derive from plant sources, yet they appeared in the study alongside fully synthetic compounds. This blurs the common consumer assumption that naturally-derived sweeteners are automatically safer than synthetic ones. The findings suggest that the relevant characteristic may not be whether a sweetener is synthesized in a laboratory or extracted from nature, but rather something about how the body processes these non-nutritive sweetening compounds.
What Comes Next for Artificial Sweetener Research and Brain Health
The Mayo Clinic study will likely prompt additional research into the artificial sweetener-cognition relationship, potentially including mechanistic studies that examine how these compounds affect the brain at molecular and cellular levels. Researchers may investigate whether effects differ based on specific genetic factors, whether the effects are reversible if consumption stops, and whether they apply to different populations. These follow-up studies could either support the current findings or reveal that the association was more complex than initial observations suggested.
From a public health perspective, these findings will likely influence dietary recommendations, particularly for middle-aged adults seeking to preserve cognitive function. While regulatory agencies have not changed artificial sweetener approvals based on this single study, the accumulating evidence may eventually influence policy. For individuals, the prudent approach is neither to panic about occasional artificial sweetener consumption nor to ignore a study of this size and rigor, but rather to consciously consider reducing intake, particularly from beverages, as a reasonable precautionary step.
Conclusion
The Mayo Clinic study published in September 2025 provides the largest evidence to date that artificial sweeteners may accelerate cognitive aging, with the highest consumers experiencing cognitive decline 62% faster than those consuming the least. The effect was most pronounced in adults under 60, suggesting that middle-aged people may be particularly vulnerable. While the study establishes association rather than proof of causation, and while the mechanisms remain unknown, the findings are substantial enough to warrant reducing artificial sweetener consumption as a practical step toward preserving brain health.
For people who rely on artificial sweeteners as part of their diet, the most practical approach is to identify the largest sources—particularly beverages—and replace them with unsweetened alternatives. This strategy avoids the all-or-nothing thinking that can make dietary change feel impossible. Even modest reductions in artificial sweetener intake, if sustained over years, could have meaningful effects on cognitive aging based on what this research suggests. As neuroscience continues to reveal the long-term effects of modern food additives on brain health, the evidence increasingly supports a conservative approach to ingredients once considered completely safe.
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For more, see NIH MedlinePlus — cognitive testing.
