Are artificial sweeteners, such as those found in Coke Zero, linked to dementia or cognitive decline?

Artificial Sweeteners and Risk of Dementia or Cognitive Decline

Based on current evidence, artificial sweeteners in products like Coke Zero may be associated with accelerated cognitive decline and should be consumed with caution or avoided, especially in individuals concerned about cognitive health.

Current Evidence on Artificial Sweeteners and Cognitive Function

Association with Cognitive Decline

• A recent 8-year prospective study found that consumption of low- and no-calorie sweeteners (LNCSs) was associated with accelerated cognitive decline, particularly affecting verbal fluency and global cognition in participants under 60 years of age 1
• Specific artificial sweeteners including aspartame, saccharin, acesulfame-K, erythritol, sorbitol, and xylitol were associated with faster decline in global cognition, particularly affecting memory and verbal fluency domains 1
• The effect was observed in both individuals with and without diabetes, suggesting this is not limited to specific populations 1

Potential Mechanisms

• Artificial sweeteners may interfere with basic learning processes that anticipate normal consequences of consuming sugars, potentially affecting neurological pathways 2
• These sweeteners can alter gut microbiota in both rodent models and humans, which may contribute to impaired glucose regulation and potentially affect brain function 2
• Early exposure to hyper-sweetened foods and beverages may have persistent effects on sweet preferences and potentially neurological development 2

Cardiovascular Risks and Potential Indirect Effects on Brain Health

• Artificial sweeteners have been associated with increased risk of cardiovascular diseases, which are known risk factors for vascular dementia and cognitive impairment 3
• A large prospective cohort study found that total artificial sweetener intake was associated with increased risk of cardiovascular diseases (HR 1.09) and particularly cerebrovascular disease risk (HR 1.18) 3
• Aspartame specifically was associated with increased risk of cerebrovascular events (HR 1.17), while acesulfame potassium and sucralose were associated with increased coronary heart disease risk 3

Guideline Recommendations and Expert Opinions

• The 2023 AHA/ACC guideline for management of chronic coronary disease notes that "recommendations are unavailable for artificial sweeteners because of limited data" 4
• ESPEN guidelines on nutrition in dementia do not specifically recommend any nutritional product (including artificial sweeteners) for preventing cognitive decline in persons with dementia due to lack of high-level evidence 4
• Dietary guidelines suggest that artificial sweeteners may be a useful intermediate step to reduce harms of sugar-sweetened beverages but should subsequently be reduced to prevent potential long-term harms 4

Safety Concerns and Controversies

• The safety of artificial sweeteners remains controversial despite extensive scientific research 5, 6
• Scientists disagree about potential relationships between sweeteners and various neurological conditions including Parkinson's disease and Alzheimer's disease 5
• Artificial sweeteners are currently being re-evaluated by major health authorities including the European Food Safety Authority and the World Health Organization 3

Practical Recommendations

• For individuals concerned about cognitive health:

  • Consider replacing artificially sweetened beverages with water or unsweetened alternatives 4
  • If transitioning from sugar-sweetened beverages, artificial sweeteners may serve as a temporary intermediate step, but should not be considered a long-term solution 4
  • Be particularly cautious with aspartame, which has shown specific associations with cerebrovascular events that could impact brain health 3

• For those at higher risk of cognitive decline:

  • Consider avoiding artificial sweeteners entirely given the emerging evidence of potential associations with accelerated cognitive decline 1
  • Focus on a balanced diet rich in natural foods rather than processed products containing artificial additives 4

Common Pitfalls and Caveats

• Don't assume "zero-calorie" means "zero health impact" - artificial sweeteners may have metabolic and neurological effects despite containing no calories 2
• Be aware that artificial sweeteners are present in thousands of food and beverage brands worldwide, not just in diet sodas 3
• Remember that individual responses to artificial sweeteners may vary based on genetics, gut microbiome composition, and other factors 2
• Consider that the research on artificial sweeteners and cognitive function is still evolving, with limitations including self-reported dietary data and potential confounding factors 1