AHA: Limit Diet Sodas and Drinks, Stick to Water Instead

A science advisory team from the American Heart Association (AHA) cautions against regular and long-term consumption of diet beverages, especially in children. They stress instead to replace sugary diet drinks with plain, carbonated, or unsweetened flavored water.

Although sweetened diet drinks have been linked to weight gain, dementia, stroke and other health problems in numerous studies, there has been non definite conclusion about exactly how diet drinks can be detrimental to one’s health.

"There's not a huge body of literature, either observational or clinical trials," explained Rachel K. Johnson, a professor emeritus of nutrition at the University of Vermont. "Based on the evidence available at this time, this is the best advice we have."

It is understandable why diet drinks are so popular; often times they are marketed as being “healthier” than their full-sugar counterparts, and some people, especially those who have been drinking soft drinks their whole lives, find it hard to completely switch to water. "[Diet drinks] may be particularly helpful for individuals who are habituated to a sweet-tasting beverage and for whom water, at least initially, is not a desirable option," the report said.

Fortunately, federal data based on self-reported surveys show that adults and young people are drinking less of both sugary and diet drinks. The average adult daily intake of diet drinks fell from 5.6 ounces in 2006 to 3.8 ounces in 2014. Consumption for kids and teens also decreased. For reference, a serving size is about 8 ounces, and a can of soda is usually 12 ounces.

The decrease is also reflected in sugary drinks; the average adult daily intake fell from 16.2 ounces in 2000 to 8.4 ounces in 2014. In 2016, the AHA issued its first scientific statement warning regarding sugar intake for kids; they cautioned that children and teens should consume a maximum of 8 ounces of sugary drinks per week.

"We want to make crystal clear it's important to maintain that [downward] trend," said Alice H. Lichtenstein, vice chair of the writing group and director of the Cardiovascular Nutrition Laboratory at Tufts University in Boston.

"We hear a lot about potential adverse effects of low-calorie sweeteners, but much of it is speculation. We have to go with the available evidence," said Lichtenstein, the Gershoff Professor of Nutrition Science and Policy at Tufts. "The best advice we can give at this time is to ramp down intake and avoid excess consumption."

Because there is "virtually no data" on the long-term effects of diet drinks, the group was especially careful with their advice to children, according to Dr. Frank Hu, chair of the nutrition department at Harvard University and professor of nutrition and epidemiology.

"One question we discussed is whether for children who are obese and who drink regular soda on a regular basis, is it OK for them to drink diet soda instead?" Hu said. "The consensus is that for short-term weight control, it's OK. Certainly, it's not the best alternative … because we all know there are more healthy alternatives, such as water, low-fat and fat-free milk."

The one exception made was for children with diabetes. These patients may substitute diet drinks for sugary drinks as needed, given that they have a balanced diet and are closely monitoring their blood glucose.

Though the AHA and the American Diabetes Association issued a scientific statement in 2012 advising that artificial sweeteners used "judiciously" in foods and beverages could help lower sugar intake, maintain a healthy weight, and lower the risk of heart disease and type 2 diabetes, it has since been concluded that the data behind the study was "limited and inconclusive."

Because AHA science advisories typically evaluate topics related to heart and brain health as a way to educate the public about the latest health care trends, this study was a bit unique. It highlighted the lack of clear evidence about diet drink studies.

However, according to nutrition researcher Christopher Gardner, diet drinks are bad, no matter the context. "Artificial soda, there's nothing good about it," said Gardner, who was not an author on the latest advisory but a lead author on the 2012 scientific statement. He is also director of Nutrition Studies at the Stanford Prevention Research Center. "There's nothing health-promoting about it. The only health-related role it has is as a transition beverage, replacing or displacing sugar-sweetened beverages."