Are Artificial Sweeteners Better Than Sugar for Your Heart?

Low-calorie sweetener use is widespread; its metabolic effect isn’t fully known

There’s a long standing debate over artificial sweeteners and weight loss. 

Non-caloric sweeteners came to the scene decades ago, offering the intense sweetness we naturally prefer, without the caloric price tag. Sweeteners such as aspartame (NutraSweet, Equal), sucralose (Splenda), saccharin (Sweet'N Low) acesulfame K (Sweet One) and neotame are practically calorie free, so replacing added sugar with them should cut calories from our daily intake,  and fewer calories should translate to weight loss, right?

Short-term clinical trials were promising: Artificially sweetened beverages may lead to short-term weight loss when they replace sugary drinks. However, there are very few long-term studies looking at what artificially sweetened beverages do to weight, and since body weight regulation is super complicated, it very well may be that over time the calories saved by switching to artificial sweeteners are replaced by other foods; in other words, diet drinks may not help you lose weight after all. Several studies actually suggest that these sweeteners fuel, rather than fight the obesity epidemic. 

Sugary drinks pose risks beyond weight gain though; they increase the risk of heart disease, type 2 diabetes and other chronic diseases. Are diet sodas better? 

Are artificial sweeteners safe?

While the weight loss benefits are still questioned, several safety concerns are being raised.  On the one hand, despite recurring worries about sweeteners and cancer risk no such link has been found.

However, there’s disturbing evidence showing a correlation between the consumption of diet drinks and the metabolic syndrome as well as type 2 diabetes, independent of obesity. Sweet taste without calories may send signals that trigger hunger, increase craving and interfere with weight regulation, and lately, studies have indicated that artificial sweeteners may induce glucose intolerance by altering gut microbes.

New research reported in the Journal of the American College of Cardiology looks at artificial sweeteners and heart health. The study includes 100,760 people, who reported on their beverage intake every 6 months. Incidents of cardiovascular disease, including heart attacks and strokes, were marked from the fourth year of study, to control for reverse causality (cardiovascular disease pushing people to quit sweet drinks rather than sweetened drinks driving cardiovascular disease).

And the results: After taking into account confounding factors, people who consumed drinks sweetened by sugar as well as people drinking artificially sweetened drinks were at significantly higher risk of cardiovascular disease, the higher the consumption the greater the risk. The authors conclude that artificially sweetened beverages “might not be a healthy substitute for sugary drinks.”

An uncontrolled experiment

In a commentary in JAMA a decade ago Dr. David Ludwig, of Harvard Medical School and Children's Hospital Boston, warned that artificial sweeteners are cause for concern, especially since we’re consuming so much of them, in “a massive, uncontrolled, and inadvertent public health experiment.” These synthetic chemicals are a relatively new addition to the human diet, their use is rising and spreading to kids, and is expected to rise even more as the efforts to limit added sugar intensify. 

And although we already know that use of low-calorie sweeteners is widespread, the known prevalence appears to be an underestimate. A new study that measures a biomarker of low-calorie sweeteners in the urine – an objective measure that doesn’t rely on dietary self-reporting – suggests that exposure to these sweeteners is much more substantial than we think. In a sample of 341 adults more than 96 percent of urine samples contained at least one urine marker of a low-calorie sweetener, and in a sample of 79 within that group, although only 5 percent of people reported consumption of artificial sweeteners, 92 percent showed the presence of a biomarker of low calorie sweeteners in their urine. Turns out, artificial sweeteners are present not just in diet drinks, but also in oral hygiene products, supplements, e-cigarettes, not to mention all kinds of foods.

Low-calorie sweetener use is widespread, even though its metabolic effect is not fully known.

So sure, excessive added sugar isn’t good for our health – it’s especially harmful in liquid form – but even if artificial sweeteners are better, it may not be by much. A science advisory from the American Heart Association advises against long term consumption of diet soda, especially for kids; for adults who consume large amounts of sugary drinks, diet drinks may be a useful strategy to reduce soda intake while moving towards more desirable options.

Overcoming the sweet-drink habit is the best option. Treats are one of life’s joys, but intense sweetness with everyday hydration isn’t good for you – even if no calories are involved.

Dr. Ayala