🔋Are Artificial Sweeteners Hurting Your Brain? (ATP#27)

It sounds too good to be true: Enjoy the sweet taste of soda, baked goods, or coffee - but without the calories and other adverse health effects of sugar. Artificial sweeteners make everything look like a guilt-free treat next to all those sugar bombs.

Sweeteners like saccharin or aspartame are widely used and appear to be a healthier alternative to sugar. But a new study suggests your brain may pay the price.

About the study

12,772 people participated initially.

The first data collection took place between 2008 and 2010, when participants were between 35 and 74 years old. The researchers collected demographic information, assessed the intake of different sweeteners in the past 12 months (aspartame, saccharin, acesulfame K, erythritol, sorbitol, xylitol, and tagatose), and conducted different tests of cognitive function, specifically memory, verbal fluency, and processing speed.

Between 2017 and 2019, roughly 8 years later, cognitive function was tested again in 9,726 people from the original sample. The researchers wanted to know if sweetener intake measured between 2008 and 2010 could predict cognitive function ~8 years later.

To this end, they divided the sample into three equal parts or tertiles based on sweetener intake at the beginning of the study:

• Tertile 1 - lowest intake (19.9 mg/day on average)

• Tertile 2 - medium intake (65.6 mg/day on average)

• Tertile 3 - highest intake (191.0 mg/day on average)

(For context: One can (355 ml or 12 oz) of Diet Coke contains around 200 mg of aspartame.)

Main results

Regarding memory decline, participants in tertile 3 showed a 32% higher rate than those in tertile 1. Verbal fluency decline was higher in tertiles 2 and 3, with 110% and 173% higher rates than in tertile 1, respectively.

When cognitive function was summarized into a single measure, the excess of cognitive aging was determined at 1.3 years for tertile 2 and 1.6 years for tertile 3. In other words, their brains aged faster than those of the people in tertile 1, who had the lowest sweetener consumption at the beginning of the study.

Interestingly, the link between sweetener intake and cognitive decline appeared only in participants younger than 60 but not in older adults.

And not all sweeteners behaved the same: tagatose showed no negative association in this study.

So what does all this mean in real life? Should you worry about your Diet Coke?

What these results mean

The study authors discuss that the metabolites from sweeteners might have neurotoxic functions or trigger inflammation in the central nervous system, which could accelerate brain aging.

Still, the results are no reason to panic (yet):

1. The study shows an association, not a causal relationship. Tertiles 2 and 3 may have had other differences with tertile 1 that could have led to faster brain aging. We just don’t know.

2. Sweetener intake was measured only once at the beginning of the study, via a questionnaire completed by participants. Food questionnaires have limited accuracy, particularly when people are asked to remember what they ingested across longer time periods (12 months in the present study!). Plus, nutritional habits also change over the years. We don’t know if sweetener intake remained constant over the ~8 years that passed between the two moments of data collection.

3. As the authors themselves discuss, they couldn’t get brain imaging data or measure other parameters that could have provided a more complete picture of the results.

4. Roughly 3,000 participants from the original sample didn’t participate in the 2017-2019 data collection, which might have affected the results if participants with specific characteristics were more likely to drop out than others.

5. Some commonly used sweeteners were missing in this study, for example, stevia, sucralose, and allulose.

So what do we do now?

This study raises concerns about the safety of sweeteners, but reverting to traditional sugar doesn’t seem reasonable due to its proven adverse health consequences.

If you ask me for advice, I honestly (and speaking more as a person than a scientist) recommend getting used to lower degrees of sweetness, because an occasional dose of sugar or sweeteners likely won’t harm you, and you won’t need more once you learn to live with lower levels of sweet taste.

And if you believe it’s impossible, hear me out: I suffered from binge eating disorder as a teenager, and the substance I was most addicted to was sugar (in the form of chocolate). In my 20s, I made a hard cut and went low-carb. What others call “sweet” now tastes excessively sweet to me.

I’m convinced we would all be better off if we got used to lower levels of sweetness (except for the food industry, of course 😬).

What else I’ve been up to:

I published a new article on Medium, where I list 10 things I don’t do as a neuroscientist, even though these behaviors are common in many people. You might recognize yourself in some of them!

Just click below to read it (a friend link is included at the beginning of the article so you can access it for free if you’re not a member).

That’s it for today!

And now?

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Until next time!

Best wishes,

Patricia (Dr. Schmidt) from creatorschmidt.com.