Artificially Sweetened Beverages and the Risk of Stroke and Dementia

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I’m often asked which is worse for health, sugar- or artificially sweetened beverages. My most common response is to recommend skipping both and choose water. However, in the era of fructose phobia and the apparent association between high fructose consumption and the risk of metabolic syndrome and diabetes, many tend to prefer artificially sweetened beverages (1,2). However, recently published scientific evidence suggests that this may be a wrong approach and that artificially sweetened soft drinks may indeed cause more harm than those containing sugar.

The main advantage of artificially sweetened beverages is typically considered to be the lack of calories compared with sugars such as sucrose or fructose.

Five “non-nutritive” artificial, sweeteners used in soft drink production have FDA approval; saccharin, acesulfame, aspartame, neotame, and sucralose. Stevia, a natural extract from the plant Stevia rebaudiana, was approved by the FDA in 2008. These synthetic substances are hundreds to thousands of times more potent than sucrose and evoke an intense sensation of sweetness in trace amounts (3).

Artificially Sweetened Beverages and the Risk of Stroke and Dementia

A recently published paper by Matthew P. Pase PhD and coworkers from Boston University School of Medicine suggests that high consumption of artificially sweetened soft drinks may be associated with increased risk of both stroke and dementia (4). In fact, it is the first study to suggest that artificially sweetened beverages, but not sugar-sweetened beverages, may be associated with risk of stroke and dementia, including Alzheimer’s disease.

Cumulative consumption of artificially sweetened beverages and event-free survival of stroke (A) and dementia (B). Green, red, and blue lines denote intake of 0/wk, 6/wk, and 1/d, respectively. DOI: https://doi.org/10.1161/STROKEAHA.116.016027

The investigators studied 2.888 participants from the Framingham Heart Study Offspring Cohort between 1991 and 2001. The mean age was 62 years, 55% were women. Beverage intake was quantified using food-frequency questionnaires. During the ten year follow-up period, 82 cases of incident stroke were observed and 81 cases of incident dementia, 63 of which were consistent with Alzheimer’s disease.

After adjustments for age, sex, education, caloric intake, diet quality, physical activity, and smoking, higher recent and higher cumulative intake of artificially sweetened soft drinks were associated with an increased risk of ischemic stroke, all-cause dementia, and Alzheimer’s disease dementia.

Those who consumed artificially sweetened soft drinks daily were approximately three times more likely to develop stroke or dementia compared to those who consumed no artificially sweetened beverages. Sugar-sweetened beverages were not associated with stroke or dementia.

The Bottom Line

The Nurses Health Study and Health Professionals Follow-Up Study found that greater consumption of both sugar-sweetened and low-calorie sodas was associated with a significantly higher risk of stroke (5).

A 2011 statement from the American Heart Association and American Diabetes Association concluded that when used judiciously, non-nutritive sweeteners (including very low-calorie sweeteners, artificial sweeteners, and non-caloric sweeteners) might help with weight loss or control, and could also have beneficial metabolic effects (6).

So clearly, the discussion about artificially and sugar-sweetened beverages has typically focused on the energy issue. And of course, the soft drink producers highlight the lack of calories as the main benefit of artificially sweetened beverages.

According to Coca-Cola; Diet Coke is the most popular calorie-free soft drink in America. It’s the original sparkling beverage for those who want great flavor without the calories – a drink for those with great taste.

According to Pepsi; Pepsi Zero Sugar or Pepsi Max is the only soda with zero calories and maximum Pepsi taste.

Interestingly, the study by Pase and coworkers also found that diabetes mellitus, which is a known risk factor for dementia, was more prevalent in those who regularly consumed artificially sweetened soft drinks.

On the other hand, it should be pointed out that this was an observational study and therefore can not determine whether there is a causal relationship between artificially sweetened soft drink intake and diabetes and stroke or dementia.

However, the fact that those who consumed artificially sweetened soft drinks daily, but not those who consumed sugar-sweetened beverages, were approximately three times more likely to develop stroke or dementia is intriguing.

About 25 percent of children and more than 41 percent of adults in the United States reported consuming foods and beverages containing low-calorie sweeteners such as aspartame, sucralose, and saccharin in a recent nationwide nutritional survey (7). Those numbers represent a 200 percent increase in the consumption of artificially sweetened beverages for children and a 54 percent jump for adults from 1999 to 2012.

These numbers highlight the potential implications of the hair-raising results presented by Pase and coworkers.

Unfortunately, in my opinion, the study has some methodological flaws. The limited number of events is clearly a problem. Furthermore, no adjustments were made for multiple statistical testing. Hence it can not be rule out that some of the findings are due to chance alone.

Another study by the same group, published online in Alzheimer’s and Dementia on March 5, shows a link between consumption of both sugar-sweetened and artificially sweetened beverages and reduction in brain volume in a middle-aged cohort (8). In the cross-sectional study, the sugary drinks, which included both soda and fruit juice, were also associated with worse episodic memory.

Apparently, the jury’s still out on the issue which is worse, sugar-sweetened or artificially sweetened. So, why not skip both and stick with water.