Taylor Swift urged to "Shake Off" aspartame

CSPI urges singer to drop Diet Coke endorsement considering cancer concerns around aspartame

The Center for Science in the Public Interest is asking Grammy-award-winning singer Taylor Swift to drop her endorsement of Diet Coke, which contains aspartame, the artificial sweetener that has caused cancer in animals. In an open letter to Swift, the food safety watchdog group told the singer that endorsing Diet Coke is better than endorsing full-calorie Coke, which promotes diabetes, heart disease, and obesity, but that diet sodas sweetened with aspartame pose their own risks.

"Your endorsement carries great weight with your millions of young fans," wrote CSPI executive director Michael F. Jacobson, who praised Swift's considerable philanthropy, including her support of several prominent cancer-related charities. "To the extent that your endorsement encourages them to begin drinking Diet Coke, or to drink more, your endorsement is likely increasing your fans' risk of cancer. Even if the increase in risk is small, we question whether you would want to lend your name, image, and reputation to any product linked to any increased risk of cancer."

Aspartame, a synthetic chemical combination of two amino acids and methanol, caused lymphomas, leukemias, kidney tumors, and breast cancer in two studies on rats. In a mouse study, aspartame caused liver and lung cancer. Scientists generally accept that if a chemical causes cancer in animals it likely increases the risk of cancer in humans. CSPI recommends that consumers avoid aspartame and has urged food manufacturers not to use it.

"As the public face of Diet Coke, Taylor Swift is the public face of aspartame," Jacobson said. "She might be doing more to promote aspartame consumption than anyone on Earth."

Taylor Swift began her tenure as a program ambassador for Diet Coke in January 2013, when she announced the partnership in a video message on YouTube. In the video she asked her fans to "like" Diet Coke's Facebook page. In October 2014, Diet Coke released an ad featuring Swift and dozens of kittens including Swift's cat Olivia Benson. Swift Tweeted a link to the ad to her Twitter followers, who now number 50 million. According to social media market research firm Demographics Pro, more than a third of those followers are age 16 or younger.

Also in October, movie-theater chain Regal Entertainment Group put Taylor Swift's image on "exclusive Diet Coke concession cups and popcorn bags." [Editor's note to dieters: A medium popcorn at Regal has 720 calories and as much saturated fat as a stick of butter.]

"Celebrities are free to endorse whatever they want, but celebrities at Swift's level can afford to be choosy and have high standards," Jacobson said. "They shouldn't use their influence, especially their influence over children, to market junk foods."

CSPI is using the Twitter hashtag #ShakeOffAspartame to publicize its concern over the singer's endorsement. Swift's song "Shake it Off" debuted at number one on the Billboard Hot 100 in September. The video has more than 470 million views on YouTube.

CSPI previously has criticized other artists and athletes who endorse non-diet soda, including Beyoncé, Katy Perry, Macklemore, Shaquille O'Neal, and Michelle Kwan.

While acknowledging that diet soda is less harmful than regular soda, CSPI recommends that consumers drink water, seltzer water, or other safe, non-caloric beverages.