MEMPHIS, TN – No need to toss out diet soda – some doctors question a study that links diet sodas and heart disease. Research presented recently at the American Stroke Association International Stroke Conference suggests drinking diet soda every day could take a toll on your heart.
But Dr. Arie Szatkowski, of the Stern Cardiovascular Center, says this doesn't mean never pick up a can of diet soda again."
“I think it’s a very flawed study to begin with,” he said. “It’s just an observational study, meaning that they just watched a group of people over a period of nine years. They took 2500 people and they gave them a questionnaire to fill out, and it was only asked one time at the beginning of the study. The questionnaire asked about your dietary habits, how much soda do you drink and what kind of soda do you drink, and then they followed them for 9 1/2 years, and then they looked at outcomes."
About 160 study participants reported drinking at least one can of diet soda every day.
“The study showed that it was 61 percent more likely for that group to have a heart attack or stroke, as opposed to the group that drank no soda at all, whether it is diet or regular soda, or the group that drank regular sodas,” Dr. Szatkowski said.
But “dietary habits can change dramatically over a 9 ½ year period of time,” he pointed out.
“So it would be better to know what happened all along the way, did you stick to the diet drink, did you not,” he said.
He also pointed out “this is an observational study, not a randomized trial.”
“Following a group that way, you could then more scientifically determine whether or not there's a cause and effect,” he said.
He also questioned whether the study accounted "for factors like family history of cardiovascular disease.”
“The physicians and the researchers who were involved in this trial they did try to account for other things that could lead to a heart attack or stroke, but they couldn’t do it for everything,” Dr. Szatkowski said. “And family history of heart disease or stroke is a very critical risk factor.”
He said many of the participants were Latino or African American -- groups that already have a greater risk for heart disease. He said the study also didn't account for the impact of eating habits.
“You know people who drink diet soda tend to drink diet sodas because they’re trying to lose weight,” he said. “So they may be more likely to eat poorly in terms of other parts of their diet.”
The study also didn’t consider the participants’ level of physical activity, and “didn’t ask what kind of diet soda you drink,” Szatkowski added.
“There are different sweeteners in the sodas, different colorings, et cetera,” he said. “We don’t even know which kind of diet soda they’re talking about.”
His advice? Don't shun diet soda because of this study – moderation is key.
“If it helps you maintain your weight, or lose weight, then I think you’re okay,” Dr. Szatkowski said. “Drinking five or six cans a day is probably not good.”
He said the study should lead to questions – not panic.
“I think it would be a disservice right now to say that there is a definite link between diet soda drinking or your future risk for heart attack and stroke without more definitive study,” he said. “It’s certainly an observation, it raises questions which observational studies should do. But now you need to move on to a more scientific trial.”
