Artificial sweeteners may increase cognitive decline!
I recall, for years, consuming diet sodas, yogurts, and other foods containing artificial sweeteners. I would also consistently add an artificial sweetener to my tea or coffee when I was younger. I am now deeply regretting those choices. A large study was published in the journal Neurology, involving over 12,000 adults with an average age of 52 and followed over 8 years, analyzing the effects of artificial sweeteners on cognitive health. What the authors found should absolutely be a wake-up call, and inform how we think about our daily diet—> consumption of artificial sweeteners was associated with an accelerated rate of cognitive decline!!
The artificial sweeteners included in the study were: aspartame, saccharin, acesulfame k, erythritol, sorbitol, and xylitol— all of which were associated with a faster decline in global cognition, particularly in memory and verbal fluency domains. Participants in the study were given baseline cognitive tests, and then retested throughout the study with tools that assessed working memory, word recall, verbal fluency, and mental processing speed.
What is particularly concerning is that the link of artificial sweeteners with cognitive decline was even stronger in those in the study with diabetes! This is important because many of my diabetic patients use artificial sweeteners as a substitute for sugar, believing they are benefiting their health. And while some of these sugar substitutes may temporarily avoid the spike in glucose levels in the blood that we typically see with sugar containing foods, consuming these sweeteners may come with a significant trade off.
There were a few potential limitations in the study, though, that are important to consider:
The researchers used self-reported dietary data, which can, at times, be inaccurate.
The mechanism of how these artificial sweeteners actually caused the cognitive decline was not explored, which does open up the possibility that the decline could be due to confounding from co-occurring health behaviors (lifestyle choices) or dietary choices in those who consume sugar substitutes. For example, is it possible that those who consume artificial sweeteners are less likely to exercise? Exercise is well known to reduce dementia risk!
Other research published in Nature Metabolism has also raised concerns that non-caloric sweeteners may actually stimulate appetite, and could be counterproductive for those with weight related medical conditions or those trying to lose weight.
I now drink my tea and coffee black. When I desire something sweet I reach for a piece of fruit. Read more about dietary approaches in my book Optimized.
