1. Heart failure
Researchers from Columbia University College of Physicians and Surgeons and the University of Miami Miller School of Medicine followed more than 2,500 adults for a decade. One group of people frequently drank regular soda, the other diet. At the end of the study, which was conducted in 2012, those who consumed diet soda had a 43% higher chance of cardiovascular disease, such as a heart attack, then those who drank regular soda.
A 2014 study found that women who had two or more diet sodas had a 30% higher risk of heart attack and were twice as likely to die than women who rarely drank diet soda.
Artificial sweeteners may cause increased consumption of high calorie foods — they simply make you crave fatty foods — leading to glucose intolerance and weight gain. Artificial sweeteners may not be natural but they are sweet, and as such they encourage sugar cravings and sugar dependence.
A 2015 study by the American Geriatrics Society of nearly 800 people over the age of 65 found that diet soda intake was related to increasing abdominal obesity. Separate research that followed people for over eight years found that those who drank artificially sweetened beverages were more likely to report increased BMIs.
According to a Gallup survey, 32% of overweight Americans say they drink diet soda, compared to 19% of those with normal weight.
A 2017 study of almost 3,000 people over 60 found that diet sodas sweetened with artificial ingredients — unlike sugar-sweetened beverages — lead to a higher risk of dementia. People who drank at least one diet beverage a day were almost three times more likely to develop dementia. The results were the same after accounting for gender, general diet, smoking, and level of physical activity.
The same study of nearly 3,000 people found that daily consumption of diet beverages was associated with increased risk of stroke and dementia over a 10-year period. Older studies have also shown a connection between low-calorie sodas and a significantly higher risk of stroke.
Researchers are not sure how exactly artificial sweeteners may increase the risk of stroke, but this is not a reason to keep them in your diet. Researchers following 127,000 people for 20 years concluded that those who consumed more than one soda per day had a higher risk of stroke, regardless of whether the soda contained sugar or was artificially sweetened.
5. High blood pressure
Hypertension increases the risk of heart attack and stroke, among other chronic health conditions. Diet sodas are linked to high blood pressure possibly because people who drink artificially sweetened beverages tend to be overweight or obese. Another possible explanation is the sodium content. One can of soda contains 40mg of sodium. Even though the recommendation is 1,500 mg per day for most adults, drinking more than one can a day can really add up, especially considering that almost all foods we consume have salt.