Science vs. Soda: What’s Really in Your Diet Coke?
By Madeline Haller
Starting in 2013, Coca-Cola Co., PepsiCo Inc., and Dr Pepper Snapple Group Inc. will launch vending machines in Chicago and San Antonio municipal buildings that have the calorie counts for each drink labeled on the button. And according to The American Beverage Association, the machines will have prompts—such as “Try a Low-Calorie Beverage”—to help consumers consider their alternatives.
But are diet sodas really going to help you stave off the pounds? Probably not.
Case in point: When researchers from the School of Medicine at The University of Texas Health Science Center San Antonio compared the waistlines of diet soda drinkers against a group of non-diet drinkers, the diet soda drinkers had 70 percent greater increases in belly bulge over the course of the 9.5-year study. (Read more Strange Reasons Why Diet Soda Makes You Fat.)
Even though that zero-calorie cola sounds like the wiser pick, have you ever actually read the ingredient label? Probably not. So we pulled the ingredients of a Diet Coke right off of its bottle: carbonated water, caramel color, aspartame, phosphoric acid, potassium citrate, natural flavors, citric acid, and caffeine. You already know about carbonated water and caffeine, so we broke down the other four mystery ingredients and inspected what’s really in your Diet Coke. (For more nutritional secrets that’ll help you drop pounds, check out The Truth About Calories.)
“Caramel color is made by a process involving the heating of corn or cane sugar and other carbohydrates to achieve the desired color.” — Coca-Cola Co.
Science weighs in: “Caramel color sounds innocent, but it’s not,” says Alexandra Caspero, R.D., owner of weight management and sports nutrition service Delicious-Knowledge.com. Research published by the federal government’s National Toxicology Program showed that long-term exposure to 4-methylimidazole—a contaminant in the caramel coloring—lead to an increase in lung cancer in male and female mice. And these findings resulted in the addition of 4-MEI to California’s Proposition 65 list of carcinogens.
What’s more, in 2011, the International Agency for Research on Cancer also concluded that caramel coloring is possibly carcinogenic to humans. And while caramel coloring is in a host of products (like baked goods and soy sauces), the frequency of how much we consume soda makes it more of a concern, says Caspero.
“Aspartame is a low-calorie sweetener made primarily of two amino acids: aspartic acid and phenylalanine. Aspartame has been shown to be safe for everyone, including children and pregnant women. When used in foods and beverages a warning on the labels is provided to people who can’t metabolize aspartame.” — Coca-Cola Co.
Science weighs in: “There are many conflicting studies on the safety of aspartame, says Caspero. Animal studies show more of an increase in cancer risk than human studies have. But there is definitely enough of a connection to avoid or limit your exposure to the additive, she explains.
Plus, the low-calorie sweetener may actually be tricking your body into weight gain. “Some studies suggest that when our taste buds sense sweetness, the body expects a calorie load to accompany it. When that doesn’t happen, it may cause us to overeat because we crave the energy rush our body was expecting,” says Cheryl Forberg R.D., author of Flavor First.
What’s more, artificial sweeteners might also dull your taste buds, meaning you eat more high-flavor, high-calorie foods to satisfy your cravings, explains Forberg. (Discover why aspartame is one of the 11 Most Controversial Food Additives.)
Phosphoric acid is used in certain soft drinks, including Coca-Cola, to add tartness to the beverage. Phosphoric acid contains phosphorus, one of the basic elements of nature and an essential nutrient. Phosphorus is a major component of bones.” — Coca-Cola Co.
Science weighs in: The acid in this ingredient is what erodes tooth enamel, Caspero says.
Additional research has also linked excessive exposure to additional adverse health issues. For example, according to a study in the journal Epidemiology, drinking two or more colas a day—diet or regular—was associated with a twofold risk of developing kidney disease. The culprit? The researchers indicated that although an exact cause is unknown, the phosphoric acid in colas has been associated with urinary changes that promote kidney stones. (When left untreated, they can lead to chronic kidney disease).
“Natural flavors are derived from the essential oils or extracts of spices, fruits, vegetables and herbs.” — Coca-Cola Co.
Science weighs in: “Hundreds of chemicals can be used to mimic the taste of natural flavors—so natural flavors can be anything,” says Caspero. “The term natural just means they are derived from foods found in nature, but doesn’t make them a health food.”
Bottom line: We’re not claiming Diet Coke is the devil of all beverages. (In reality, these are The 20 Worst Drinks in America.) But just because something is zero-calories, doesn’t mean it’s the wisest drink option in the vending machine. If you’re really craving a soda, Caspero suggests treating it the way you would a brownie or ice cream: every now and then is fine, but it shouldn’t be an everyday indulgence.