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One Major Side Effect of Drinking Diet Soda Every Day, Say Doctors

Diet soda may not be a healthier alternative to sugar sweetened beverages.
FACT CHECKED BY Olivia Tarantino

An increasing number of studies suggest that choosing a Diet Coke instead of a Coca-Cola to trim some calories is not necessarily making a healthier choice. While many artificially sweetened beverages contain zero calories, drinking them regularly may put you at risk for health complications typically associated with being overweight, namely, metabolic disorders like cardiovascular disease.

Although artificial sweeteners like aspartame (one of the more popular ingredients in diet soda) are approved for use in foods and beverages by the U.S. Food & Drug Administration, that doesn't mean that they're good for you. "Given the association we found between artificial sweeteners and the excess cardiovascular risks […] it is best to limit or avoid aspartame," says nutrition scientist Yasmin Mossavar-Rahmani, Ph.D., an associate professor of epidemiology and population health at Albert Einstein College of Medicine.

About one-fifth of the U.S. population consumes diet beverages every day, according to the Centers for Disease Control and Prevention (CDC). This suggests that many people may be unaware of the possible downsides of choosing artificially sweetened beverages for weight management. Read on for an overview of some of the research. After speaking with experts and combing through studies, we've found that one major side effect of drinking diet soda you never considered before is that you could be putting your heart health at risk.

RELATED: 5 Drinks That May Lead to a Heart Attack, According to Science

Studies suggest that diet soda intake is correlated with cardiovascular-related health issues.

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In a 2012 study in the Journal of General Internal Medicine, researchers surveyed 2,564 participants who were under the age of 40 and did not have previous cardiovascular-related health issues and documented their diet soft drink consumption for 10 years. During that time, 591 vascular events were reported; 225 of them were strokes, 155 were heart attacks, and 351 resulted in death.

After controlling for health, age, physical activity, and lifestyle factors, Hannah Gardener, Ph.D., an epidemiologist with the University of Miami Miller School of Medicine, and her team of researchers found that participants who drank diet soft drinks daily had an increased risk of vascular events compared to those who drank no diet beverages.

"The results of our study suggested that people who drank diet soda frequently (e.g., daily) had a higher risk of vascular outcomes like heart attacks and strokes as well as diabetes," comments Dr. Gardener. "There is still more work to be done to determine the exact mechanisms that explain this association as well as the ingredients in diet soda that may be driving the association."

Researchers at the University of Iowa found similar results by analyzing data from the Women's Health Initiative (WHI), which tracked the medical histories and health habits of more than 93,000 women. In comparing women who consumed two or more diet drinks a day to those who never or occasionally did, they showed that diet beverage drinkers were 30% more likely to have a cardiovascular event and 50% more likely to die from a related disease.

"It's too soon to tell people to change their behavior based on this study; however, based on these and other findings we have a responsibility to do more research to see what is going on and further define the relationship, if one truly exists," Ankur Vyas, MD, a fellow in cardiovascular disease at UI Hospitals and Clinics, told the American College of Cardiology, "this could have major public health implications." These implications may include coronary heart disease, congestive heart failure, heart attack, and stroke.

Drinking artificially sweetened drinks like soda can also increase your risk of stroke.

Stroke was also linked to artificially sweetened beverage consumption in a 2019 study from the American Heart Association published in its journal, Stroke. Researchers found that women with high intake levels of artificially sweetened beverages throughout their lives had an increased risk of stroke, which in some cases, led to death.

These women were relatively healthy 12 years prior, but after the long-term consumption of diet beverages, many of the participants experienced a decline in their overall health and were diagnosed with a serious cardiovascular-related illness.

"We found that a particular kind of stroke, affecting the very small arteries of the brain, was particularly strongly associated with artificially sweetened beverages," says researcher Brian Silver, MD, a neurologist with the University of Massachusetts Memorial Medical Center. "While we can't prove cause and effect, the study suggests that limiting consumption of these kinds of [artificially sweetened] beverages may result in reduced risk [of stroke]."

The inflammatory qualities of artificial sweeteners may play a role in diet soda's connection to heart issues.

Diet beverages are typically sweetened with such sugar substitutes as saccharin, acesulfame, aspartame, neotame, or sucralose. And they tend to be considerably sweeter than regular table sugar (sucrose). Aspartame, one of the most common artificial sugar additives in diet soda, for example, is 180 to 200 times sweeter than sucrose.

Dr. Mossavar-Rahmani explains how artificial sweeteners like aspartame may have inflammatory potential, which may cause an increased risk of stroke and coronary heart disease. "It is possible that the artificial sweeteners or the caramel coloring (as in colas) have inflammatory potential that is associated with increased risks for stroke and coronary heart disease and reduced life span," says Dr. Mossavar-Rahmani.

Should you stop drinking diet soda?

Given the association between artificial sweeteners and excess cardiovascular risks, Dr. Mossavar-Rahmani suggests that it is best to limit or avoid diet beverages that contain artificial sugars like aspartame.

If you are going to consume diet drinks, avoid doing so in excess—i.e., aim for less than one per week. And remember that there are alternative beverages to diet soda that have been shown to have beneficial health effects.

"People should focus on consuming more water, coffee, and tea instead of any soda (diet or regular) or other sweetened beverages, as we have good evidence to suggest that water, tea, and coffee have positive vascular health effects," says Dr. Gardener.

Jessica DeMarino
Jessica DeMarino is a freelance journalist with a passion for health and fitness. Read more about Jessica
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