New research presented in the American College of Cardiology Scientific Sessions is raising questions about the connection between diet drinks and heart problems in post-menopausal women, with one cardiologist saying more studies are needed.

The lead researcher on the study, Dr. Ankur Vyas, said although it’s not an extreme risk, there is an association between high levels of diet drink consumption and mortality.

The data they used in the research was drawn from the Women’s Health Initiative, a study of 60,000 participants.

The team of researchers from the University of Iowa Hospitals and Clinics zeroed in on diet drink consumption in relation to cardiovascular issues in women aged 50 to 79.

Dr. Jeffrey Kuvin

Dr. Jeffrey Kuvin calls this research a thought provoking initial analysis, but one that requires further study. (Tufts Medical Center)

"And they saw is what I would consider a fairly striking finding," said Dr. Jeffrey Kuvin, a cardiologist at Tufts Medical Center and the incoming co-chair of the annual Scientific Sessions of the American College of Cardiology.

"The finding is still subject to further analysis and randomized controlled studies, but the authors found that those who consumed two or more diet drinks per day were approximately 30 per cent more likely to suffer a cardiovascular event and 50 per cent more likely to actually die from cardiovascular disease."

For the study, the women were divided into groups. The first and largest group drank up to three diet drinks a month. The second group drank between one and four each week, and the third group consumed five to seven diet drinks per week. The fourth and smallest group drank two or more diet sodas or diet fruit drinks every day.

Kuvin said results were adjusted for risk factors that could sway the data one way or the other.

"They took into consideration, age, race, smoking, other known risk factors for heart disease like diabetes, high blood pressure, cholesterol, body mass index … physical activity and some nutritional elements as well," he said.

And while an increased risk was notable in the group that consumed two or more diet drinks per day, the other three groups had about the same level of risk.

'I think, based on what we know so far, that would be extremely premature to consider this as a health hazard.'- Dr. Jeffrey Kuvin

Kuvin said more research is needed to figure out the causal relationship between diet drinks and heart disease.

Studies about health problems in relation to sugary drinks are common, but this isn’t the first time the connection between health issues and diet beverages has been put under the microscope.

"There have been some reports suggesting a link between diet drinks and metabolic syndrome," Kuvin explained, "which is a grouping of patients who have obesity, blood sugar instability, high blood pressure and some cholesterol abnormalities."

He said the next step is to think about potential causes, looking at a randomized controlled study to analyze this particular variable in more depth.

"Is this a smoking gun, or is this a bit of statistical analysis that’s thought-provoking but doesn’t really play itself out in more controlled study?" he said.

"I think, based on what we know so far, that would be extremely premature to consider this as a health hazard."