It seemed like a good idea for soda lovers: Alternatives to sugary cola, led by Dr. Pepper, The Coca-Cola Company and PepsiCo, offer consumers diet drinks with that familiar sweet taste, carbonation fizz and a caffeine boost, but without those pesky calories.
But in recent years, there’s been a diet soda backlash. Some research suggests, although doesn’t prove, that artificial sweeteners in diet drinks may be unhealthy and could have an unintended boomerang effect on appetite. As a result of consumers’ concerns, diet soda sales have been dropping for several years, with a more than 6 percent fall for Diet Coke and a roughly 5 percent fall for Diet Pepsi sales volume in 2014, according to figures from Beverage Digest. In April, Fortune reported that PepsiCo is replacing the aspartame — a sweetener linked to health risks at high doses in animal studies — in Diet Pepsi with sucralose, which is considered safer. Below, experts weigh in on the potential risks of diet sodas, healthy alternatives and how much is too much.
Moderation, Moderation
Dr. Jessica Bartfield, a specialist in internal medicine and bariatrics, is often asked about diet soda by her weight-loss patients at the Loyola Center for Metabolic Surgery and Bariatric Care. When she asks patients how much they drink, she says it’s important to define what “a lot” means to them — is that three mini-cans or three Big Gulps?
“As a rule, one or two cans of diet soda or can per day is probably fine,” Bartfield says. “One to two packets of artificial sweetener in your cup of coffee or tea, once a day, is fine. More than that, I would recommend paring down just for overall health.”
“There’s certainly some interesting research or data on diet sodas that should give some pause to how we use them and recommend them,” Bartfield says. Still, she points to a lack of cause-and-effect, human studies proving harmful effects of diet sodas such as higher risk of metabolic conditions or increased appetite. “But at the same time,” she says, “too much of a good thing is still too much. Moderation is key, and higher consumption of diet sodas may absolutely be harmful to one’s health.”
Tricking Your Taste Buds?
“It’s general knowledge in the last few years that diet soda has been in kind of a free fall,” says Dr. Michael Greger, a physician and founder of NutritionFacts.org. “But it’s still a multibillion dollar industry.”
Many believe that growing mistrust of artificial sweeteners is fueling diet soda‘s declining sales . Diet Coke contains aspartame, while newly revamped Diet Pepsi contains sucralose along with a second artificial sweetener, acesulfame potassium or Ace-K.
Greger points to a “concerning” recent study on the neurological-behavioral effects of aspartame. Healthy adults were randomly assigned to follow either a low-aspartame or high-aspartame diet. Even though the high-aspartame diet was below maximum acceptable daily levels, people on it were more irritable, showed more signs of depression and did worse on spatial orientation tests.
Other studies, while not randomized, have found an association between artificial-sweetener use and weight gain, Greger says. One common explanation has been reverse causation: that “people aren’t fat because they drink diet soda; they drink diet soda because they’re fat.” But, he says, “less-benign” possibilities exist, backed with some evidence.
One theory is that, consciously or not, people may allow themselves an extra serving or piece of cake because they’ve consumed artificially sweetened products — similar to drinking diet soda with a fast-food meal.
Another theory stems from survival instinct, Greger says: “You drink a can of Diet Coke and your brain thinks you just stumbled across a wild blueberry bush and sends these urgent signals to ‘Consume, consume — boost your appetite.'” A third possibility, he says, is that “artificial sweeteners can counterintuitively lead to weight gain as they maintain our cravings and dependency on all things sweet.”
The big question is whether some artificial sweeteners are safer than others. Because aspartame is older, more data are available than for relative newcomer sucralose. Of existing research, Greger says, there’s been a “remarkable lack of studies saying anything bad about Splenda.”
Weight-Loss Tool
One obesity expert says concerns over artificially sweetened drinks have been overstated. Diet soda is a tool, among others, which helps some people lose weight, say James Hill, executive director of the University of Colorado’s Anschutz Health and Wellness Center, and director of the Colorado Nutrition Obesity Research Center.
In a survey led by Hill, of the 434 members of the National Weight Control Registry who had succeeded in maintaining weight loss for more than one year, participants said that along with drinking more water and cutting regular-calorie drinks, changing to low- or no-calorie sweetened beverages helped them control calories. And in a June 2014 study in the journal Obesity, Hill found these beverages worked as well or better than water in a 12-week weight-loss program comparing some 300 participants. At the end of the study, the diet-drink group showed a slightly higher average weight loss than the water drinkers, with otherwise similar results in terms of waistline-size changes, blood sugar and blood pressure. Hill says it’s uncertain why diet sodas were more effective for weight loss in this study.
Hill discloses that the study was funded by the American Beverage Association, a national trade group, and that he has served as a consultant with Coca-Cola and the Calorie Control Council.
“We spend a lot of time helping people lose weight and we give [them] so many things to do in weight loss,” Hill says. Of all the things they need to focus on, he tells them, whether or not they consume diet sodas is low on the list.
To date, six sugar substitutes are approved by the Food and Drug Administration as food additives in the U.S.: saccharin (Sweet’N Low), aspartame (Equal, NutraSweet), Ace-K, sucralose (Splenda), neotame and advantame.
“This isn’t an issue, in my opinion, where we need more data,” Hill says. “I trust the regulatory bodies that have analyzed the science,” he says, including recent reports that have reiterated the safety of aspartame.
Water Wins
For Bartfield’s patients, one goal is to move them from diet soda to water, flavored however they like, as their beverage of choice. Ideal flavor sources could be sliced-up cucumbers, lemons and limes; some patients opt for strawberries or pineapple in their water. “They’ve got great gadgets on the market now that allow for fruit-infused water that is essentially still very healthy and has low-calories,” she says.
Coffee and tea are fine, Bartfield says, with many studies showing “excellent” antioxidant properties for tea. Catechins found in green tea may even help with metabolism and weight management. One thing to watch out for is creamers — both the calories and chemicals listed in the ingredients. Some newer brands offer fewer, simpler ingredients. Or, she suggests, consider using low-fat or skim milk instead.
Greger says if carbonation is your thing, club soda is a good alternative. If you’re not thrilled with the flavor, he suggests adding herbs, berry purée or a little fruit-juice concentrate.
One beverage switch Greger does not recommend is turning back to traditional sugary soda. “Regular soda is bad,” he says. “Whether it’s sugar or high-fructose corn syrup, we’re realizing now that these industrial sugars are bad in terms of increasing risk for fatty-liver syndrome, high blood pressure and some other things.”
Several years ago, the American Journal of Clinical Nutrition published a ranking of popular U.S. beverages according to their health and nutritional benefits. The top choice was drinking water followed by (unsweetened) tea and coffee; low-fat and skim milk and soy beverages; non-calorie sweetened beverages — like diet soda; drinks with some nutritional benefits, such as fruit and vegetable juices, whole milk, alcohol and sports drinks; and last came calorie-sweetened “nutrient-poor” drinks — like regular soda.
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Is Diet Soda Falling by the Wayside? originally appeared on usnews.com
