A landmark longitudinal study of 12,772 adults revealed that individuals under age 60 who consumed the highest amounts of artificial sweeteners experienced a 62% faster decline in memory and thinking skills — equivalent to roughly 1.6 extra years of cognitive aging over an eight-year period.

Specific Sweeteners: Six sugar substitutes were directly linked to faster cognitive decline: aspartame, saccharin, acesulfame K, erythritol, sorbitol, and xylitol. Tagatose was the only sweetener studied that showed no such link.

Sucralose (Splenda): Synthesized from sugar, roughly 600 times sweeter than table sugar, and stable enough for baking.

Aspartame (Equal, NutraSweet): About 200 times sweeter than sugar. Often used in diet sodas but degrades at high temperatures.

Saccharin (Sweet'N Low): 200 to 700 times sweeter than sugar; one of the oldest and most widely recognized substitutes.

Acesulfame Potassium (Ace-K, Sunett, Sweet One): 200 times sweeter than sugar. It has a slightly bitter aftertaste, so it is commonly blended with other sweeteners.

Neotame (Newtame): Derived from aspartame, it is roughly 8,000 times sweeter than sugar.

Advantame: The most potent of the group, about 20,000 times sweeter than sugar, and highly heat-stable.

Erythritol

Xylitol

Sorbitol

Maltitol

American Academy of Neurology: Some sugar substitutes linked to faster cognitive decline

Other articles are available from Mayo Clinic, Johns Hopkins, etc.