Do Artificial Sweeteners Cause Alzheimer’s and Dementia?

Image showing glass of diet soda containing artificial sweeteners

Do Artificial Sweeteners Cause Alzheimers and Dementia?


We all know that too much sugar is bad for us. Most of us have been cutting down our sugar intake accordingly, opting for ‘diet versions’ instead.  This often involves a sugar substitute. But could this increased use of artificial sweeteners be causing the current rise in dementia, including Alzheimer’s disease?

Concerning Research


Several studies in the past have linked carbonated artificially sweetened drinks to a higher risk of vascular conditions and heart disease and, ironically, an increased waistlineHowever, more recently, links have been made to the effects of aspartame on the brain.


For example, in 2008,  research published in the European Journal of Clinical Nutrition raised significant concerns regarding the adverse effects of the artificial sweetener aspartame on the brain chemistry. It found that excessive intakes of aspartame could be linked to an increase in certain mental disorders and compromised learning.


In 2014, aspartame was again called into question, with a particularly concerning link being made between aspartame and Alzheimer’s disease. The research was published in the American ‘Journal of Alzheimer’s Disease’ and suggested that the key component of aspartame was formaldehyde-forming methanol. When rhesus monkeys were fed methanol over a prolonged period, there was a marked decline in memory performance. It was noted that this decline was alarmingly similar to Alzheimer’s. Of equal concern was the development of amyloid plaque formations within the brains of the monkeys given methanol. These same plaques are typically found within the brains of human Alzheimer’s sufferers.


In April 2017 a further study was published, this time in the American Heart Association’s journal, ‘Stroke’. The researchers used data collected from more than 5,000 volunteers over the past 50 years (the Framingham Heart Study).  Participants recorded their beverage intake as part of the lifestyle/ diet questionnaires completed throughout the study. The study attracted significant media attention, due to its findings.




The study discovered that, “Drinking at least one artificially sweetened beverage daily was associated with almost three times the risk of developing stroke or dementia compared to those who drank artificially sweetened beverages less than once a week”.


Study limitations


Whilst concerning, the study has attracted a number of criticisms.  Firstly, and as the researchers themselves cautioned, ‘it remains unclear whether artificial sweeteners cause hypertension [a condition associated with an increased risk of dementia and stroke] or whether diet beverages are favoured by those most at risk’.


The researchers also stressed that they could not prove a causal link between sweeteners and stroke/dementia. This is  because their study was based on the typically unreliable process of self-reporting.


There was also a reduced link when known risk factors for Alzheimer’s (genetics, diabetes, heart disease, cholesterol and weight) were accounted for. Indeed, as Dr Elizabeth Coulthard  of the University of Bristol, helpfully suggested: “This makes it more likely that there is a group of people who both use artificially sweetened drinks and are at higher risk of dementia, presumably because they have a risk factor, such as diabetes, for which a low sugar diet has been recommended.” 


It should further be noted that the researchers did not assess the exact level (and type) of artificial sweetener involved.  Many of the more modern sweeteners often used today, such as sucralose and stevia, were only widely introduced in the last decade and therefore would not have been consumed by the sample subjects as widely as aspartame, acesulfame-K and saccharin.   The new generation sweeteners require further research accordingly.


In addition, the study only considered carbonated artificially sweetened drinks. We at the LPA Advice Company note that other studies have linked phosphates in fizzy drinks to adverse health effects, to include premature aging (at least in mice).




In view of these limitations, experts and health charities have warned against reading too much into the findings. They have also pointed out that the research does not show that artificially sweetened drinks cause dementia.


Nevertheless, as Dr James Pickett, head of research at Alzheimer’s Society points out, “it does highlight a worrying association that requires further investigation”.


As Dr Sancho, head of research at Alzheimer’s Research UK recommends, The best current evidence suggests that when it comes to reducing your risk of dementia, what is good for your heart is also good for your head. Eating a healthy balanced diet, keeping physically and mentally active, not smoking, drinking in moderation, maintaining a healthy weight and keeping cholesterol and blood pressure in check are all good ways to support healthy brain ageing.


We at the LPA Advice Company consider in the meantime that there’s much to be said for a good old glass of water and the occasional glass of red wine. Everything in moderation, naturally.

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