Is diet soda better for your heart?

There’s a long standing debate over diet soda 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 soft drinks may indeed produce 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 soft drinks may not help you lose weight after all. Several studies actually suggest that these artificially sweetened sodas 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? 

Is diet soda safe?

While the weight loss benefits of diet sodas 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. Artificial sweeteners in the market are approved by the FDA and considered safe.

However, there’s disturbing evidence showing a correlation between the consumption of diet soft drinks and the metabolic syndrome as well as type 2 diabetes, even when obesity is controlled for. Sweet tasting drinks without calories may send signals that trigger hunger, increase cravings and interfere with weight regulation, and lately, studies have indicated that artificially sweetened soda may induce glucose intolerance by altering gut microbes.

A new study reported in the Journal of the American College of Cardiology looks at artificially sweetened drinks 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 added sugar as well as people who drank artificially sweetened soft 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.”

A temporary fix

For sure, excessive added sugar isn’t good for our health – and it’s especially harmful in liquid form – but even if artificial sweetened soft drinks 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, they suggest that diet drinks may be a useful strategy to reduce soda intake while moving towards more desirable options. Ultimately, though “other alternatives to SSBs (sugar sweetened beverages), with a focus on water (plain, carbonated, and unsweetened flavored), should be encouraged.”

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

Dr. Ayala