Your Diet Soda Habit May Be Aging Your Brain Faster Than You Think

You might think of cognitive decline as an inevitable part of aging, but a new study suggests that what you drink and eat could be speeding up the process. Researchers have discovered a troubling link between artificial sweeteners and how quickly your memory and thinking skills fade over time. The good news? Understanding this connection might help you make smarter choices about the foods and beverages you consume daily.

The Study: What Researchers Found

Scientists followed 12,772 adults with an average age of 52 for about eight years, tracking their artificial sweetener consumption and testing their cognitive abilities at regular intervals. The results were striking: people who regularly consumed higher amounts of artificial sweeteners experienced a 62% faster decline in thinking and memory skills compared to those who consumed the least. To put that in perspective, researchers noted this decline is equivalent to about 1.6 years of accelerated aging. Even the middle group—those with moderate artificial sweetener intake—showed a 35% faster decline, equivalent to roughly 1.3 years of aging.

The study specifically linked six artificial sweeteners to cognitive decline: aspartame (found in diet drinks and dairy products), saccharin (Sweet 'N Low), acesulfame-K (Equal and other products), erythritol (popular in keto-friendly items and Truvia), sorbitol (used in sweets), and xylitol (found in gums and oral care products).

Why This Happens: The Brain Connection

The exact mechanism isn't completely understood, but researchers have some compelling theories. One hypothesis is that artificial sweeteners may trigger inflammation in the brain, which can slow down memory and critical thinking. Sugar alcohols like erythritol and sorbitol may also alter your gut bacteria and compromise the blood-brain barrier—the protective layer that keeps harmful substances out of your brain.

Another concern is that your brain might not be getting the fuel it needs. "These artificial sweeteners do not provide old-fashioned sugar or glucose into your body that is needed to be broken down for energy and normal brain function," explains Dr. Clifford Segil, a neurologist at Providence Saint John's Health Center. Essentially, if your diet is heavy in artificial sweeteners, your brain may be struggling to function optimally simply because it's not receiving the glucose it requires.

Who's at Greatest Risk?

People with diabetes showed an even faster rate of cognitive decline in the study. This may be because people with diabetes are already at higher risk for memory and thinking changes due to high blood sugar and insulin resistance affecting blood vessels and the brain. Additionally, people with diabetes tend to consume more artificial sweeteners as a sugar substitute, increasing their overall exposure. Diabetes itself is already a strong risk factor for cognitive decline related to Alzheimer's disease and vascular dementia, making the brain more vulnerable to additional harmful exposures.

What Should You Do?

Experts aren't saying you need to eliminate artificial sweeteners entirely, but they do recommend cutting back—especially if you're a daily user. "It is wise to limit consumption as much as possible, ideally avoiding daily use," says Dr. Claudia Kimie Suemoto, a study co-author and associate professor at the University of São Paulo.

If you're looking to replace diet sodas and artificially sweetened products, consider reaching for whole fruits instead. "Fruits are the best source of natural sugars and should really be used in place of diet drinks or protein bars to be healthy," Dr. Segil recommends. Beyond sweetener choices, supporting your brain health means focusing on eating whole foods, staying physically active, and getting plenty of sleep.

The bottom line: occasional use of artificial sweeteners likely isn't something to worry about, but if you're consuming them daily, it may be worth reassessing your habits. Your future self—and your memory—might thank you.