WEST LAFAYETTE, Ind. (AP) — Walking back to work after a trip to Chauncey Hill for fountain soft drinks, the two women had their health in mind.
Suzanne Payne had a regular soft drink, but knew it was a rare, sugary treat that she probably wouldn't finish. Susan Corwin chose a diet, caffeine-free drink.
Which soft drink — regular or diet — is the healthier choice?
That's the wrong question to ask, said Susie Swithers, a professor of psychological sciences and a behavioral neuroscientist at Purdue University. She said the real question is: What is our daily sugar intake?
"It's about the overall sweetening of our diets," she told the Journal & Courier (http://on.jconline.com/12rAEgR ).
A cultural shift has made having daily soft drinks acceptable, she said.
"It's really candy in a can. If people think of it as candy, they would say that they wouldn't have candy at every meal."
The message has been that diet soda is healthier since it has artificial sweetener and no calories, but Swithers said tracking sugar intake means limiting real and artificial sugars.
She reviewed recent scientific studies about the long-term link between artificial sweeteners and health outcomes.
"Findings from a variety of studies show that routine consumption of diet sodas, even one per day, can be connected to higher likelihood of heart disease, stroke, diabetes, metabolic syndrome and high blood pressure, in addition to contributing to weight gain," she said.
"Although it seems like common sense that diet sodas would not be problematic, that doesn't appear to be the case."
Her findings were published Wednesday in "Trends in Endocrinology & Metabolism."
The study triggered an immediate reaction from the American Beverage Association, the trade association for the non-alcoholic drinks industry.
In an emailed statement the organization called Swithers' study "an opinion piece, not a scientific study."
"Low-calorie sweeteners are some of the most studied and reviewed ingredients in the food supply today. They are safe and an effective tool in weight loss and weight management, according to decades of scientific research and regulatory agencies around the globe."
Swithers said there could be several causes for the link between negative health outcomes and artificial sweeteners.
When the body tastes something sweet, it reacts to prepare for calories and sugar intake, she said. But when that doesn't happen — because the sweetener is artificial — the body reacts again, learning that sweet doesn't mean calories.
Then, when a diet soda drinker eats something sugary, the body doesn't react properly, Swithers said. She said that may be why people who drink a mix of diet and regular soda have the largest chance of negative health outcomes.
Another possibility is that people who drink diet soft drinks think they are being health conscious, so they splurge with a piece of cake — replacing the calories they just avoided, Swithers said. Or it may be a combination of factors, she said. She said some possibilities have been proven in animals but not humans.
Since there isn't a large body of research to discourage artificial sweeteners, Patty Denton, a dietitian at IU Health Arnett, said she doesn't discourage them. However, she said, sugars should be consumed in moderation. Even some flavored waters and energy drinks contain sugar. A can of regular soda can have 150 calories.
For Payne, a regular soft drink is a special treat. Corwin said caffeine-free and diet drinks have helped her cut down on calories.
"At the end of the day," Denton said about gaining and losing weight, "it's calories in and it's calories out."
Information from: Journal and Courier, http://www.jconline.com