Most Artificial Sweeteners Linked to Faster Cognitive Decline—But Not Tagatose

A new peer-reviewed paper in Neurology followed 12,772 Brazilian adults for ~8 years and found that people consuming the highest amounts of low- and no-calorie sweeteners tended to experience faster declines in memory, verbal fluency, and overall cognition compared with those consuming the least. Importantly for our community, tagatose was the one sweetener in the study not associated with cognitive decline.

What the researchers did (and why it matters)

Participants (average age ~52 at baseline) completed detailed food-frequency questionnaires and periodic cognitive testing across three waves (2008–2019). Researchers then looked at combined and individual intake of seven sweeteners: aspartame, saccharin, acesulfame-K, erythritol, xylitol, sorbitol, and tagatose. Using mixed-effects models, they tracked how cognition changed over time in relation to sweetener consumption.

What they found—by the numbers

• Those in the top intake group for low-/no-calorie sweeteners showed a 62% faster decline in global cognition, 32% faster decline in memory, and a much steeper drop in verbal fluency versus the lowest-intake group.
• Effects tended to be stronger under age 60; the study did not see a clear association in adults 60+.
• Looking at individual sweeteners, aspartame, saccharin, acesulfame-K, erythritol, xylitol, and sorbitol were each associated with faster decline in at least some cognitive domains. Tagatose showed no such link in this cohort.
• Associations appeared stronger among people with diabetes (memory and global cognition) and present in those without diabetes (verbal fluency and global cognition).

So...what is tagatose?

Tagatose is a naturally occurring "rare sugar" that tastes and cooks like sugar (it's a reducing sugar, so it participates in browning reactions that help deliver sugar-like flavor in baked goods). It has a very low glycemic index and lower caloric value than sucrose. Tagatose has been evaluated by regulators worldwide and is permitted for use in foods.

What this study means for your sweetener choices

1. Don't chase "zero" at any cost. The Neurology findings add to a growing literature suggesting that some artificial and sugar-alcohol sweeteners may carry trade-offs for brain health—particularly in middle age. Moderation and ingredient quality matter.
2. If you're swapping sugar, choose thoughtfully. Evidence from this cohort points to tagatose as a not-associated option regarding cognitive decline signals, while still delivering sugar-like taste and bakeability. That makes it an attractive candidate for everyday swaps at home.
3. Look beyond packets. Many "sugar-free" ultraprocessed foods stack multiple sweeteners. Check labels—if your goal is a simpler, more whole-food-leaning pantry, keep the ingredient list short and familiar.

Easy ways to try Tagasweet™ in your kitchen

• Coffee & tea: Start 1:1 where you'd normally use sugar.
• Baking: Because Tagasweet browns readily (it's a reducing sugar), it's great for cookies, quick breads, and caramelized glazes—monitor color as you may achieve golden tones a bit faster than with sucrose.
• Yogurt & oats: Stir in for balanced sweetness without the sugar spike characteristics of sucrose-sweetened versions.

The Neurology study is a thoughtfully designed, long-term analysis linking higher intake of several low-/no-calorie sweeteners to faster cognitive decline—with tagatose as the notable exception in this dataset. While more clinical research is needed to establish mechanisms and causality, choosing simpler, well-studied ingredients like tagatose is a practical way to sweeten smartly.