)
Artificial sweeteners present in diet sodas have long been promoted as a healthier alternative to sugar, especially for people trying to lose weight or manage diabetes. But a new study has raised fresh questions about whether consuming them regularly could affect brain health over time. Published in the journal Neurology by the American Academy of Neurology, the study found that middle-aged adults who consumed the highest amounts of artificial sweeteners experienced significantly faster cognitive decline than those who consumed the least. While the findings do not prove that artificial sweeteners cause memory problems, researchers say they highlight the need to better understand how these commonly used sugar substitutes may influence long-term brain health.
What Did The Study Find?
Researchers followed 12,772 adults with an average age of 52 years for approximately eight years. Participants completed food frequency questionnaires that estimated their intake of seven commonly used sweeteners:
- Aspartame
- Saccharin
- Acesulfame K
- Erythritol
- Xylitol
- Sorbitol
- Tagatose
Their memory and thinking abilities were assessed at the beginning, middle and end of the study. The researchers found that adults under 60 years of age who consumed the highest amounts of artificial sweeteners experienced a 62% faster decline in memory and cognitive function compared with those consuming the least. This difference was estimated to be roughly equal to an additional 18 months of brain ageing. Even people with moderate sweetener intake showed a 35% faster cognitive decline than low consumers.
People With Diabetes Showed Stronger Associations
The link between artificial sweetener intake and cognitive decline appeared strongest among participants with diabetes. According to the study's lead author, Dr Claudia Kimie Suemoto from the University of Sao Paulo, "Low- and no-calorie sweeteners are often seen as a healthy alternative to sugar; however, our findings suggest certain sweeteners may have negative effects on brain health over time." She noted that people with diabetes are generally more likely to consume sugar substitutes, making this finding particularly important for that population.
Why Didn't Researchers Find The Same Link In Older Adults?
Interestingly, researchers did not observe a significant association among participants aged 60 years and older. However, experts caution that this should not be interpreted as evidence that artificial sweeteners become harmless after 60. According to Dr Andrew Budson, Lecturer in Neurology at Harvard Medical School, cognitive decline varies much more widely in older adults, making smaller effects harder to detect statistically. In other words, the absence of a significant association does not necessarily mean there is no effect.
Where Are Artificial Sweeteners Found?
Many people associate artificial sweeteners with diet soft drinks, but they are present in a much wider range of foods than many realise. Common sources include:
- Diet soft drinks
- Sugar-free juices
- Protein bars
- Sugar-free desserts
- Low-calorie yoghurts
- Chewing gum
- Flavoured drinks
- Sugar-free biscuits and snacks
- Packaged "diet" foods
Because these ingredients appear in many processed foods, people may consume much larger amounts than they realise.
Does This Mean You Should Stop Using Artificial Sweeteners?
Not necessarily. The researchers emphasise that this was an observational study, meaning it identified an association rather than proving that artificial sweeteners directly caused cognitive decline. Other dietary habits, lifestyle factors and underlying health conditions may also influence brain health. More research is needed to determine whether specific sweeteners affect the brain differently and whether reducing their intake lowers cognitive risk.
How Can You Protect Brain Health?
Experts generally recommend focusing on overall dietary quality rather than relying heavily on sugar or sugar substitutes. Simple habits that support long-term brain health include:
- Eating plenty of fruits and vegetables
- Choosing whole grains over refined carbohydrates
- Limiting ultra-processed foods
- Staying physically active
- Managing diabetes, blood pressure and cholesterol
- Getting adequate sleep
- Avoiding smoking and excessive alcohol
For people who regularly consume "sugar-free" products, checking ingredient labels may also help monitor overall sweetener intake. The new study suggests that higher consumption of artificial sweeteners may be associated with faster memory and thinking decline in middle-aged adults, particularly those under 60 years of age and people with diabetes.
Although the findings do not establish cause and effect, they add to growing research examining how dietary choices influence brain health. Until more evidence becomes available, experts suggest consuming artificial sweeteners in moderation while focusing on a balanced, minimally processed diet for overall health.
Disclaimer: This content including advice provides generic information only. It is in no way a substitute for a qualified medical opinion. Always consult a specialist or your own doctor for more information. NDTV does not claim responsibility for this information.