FILE PHOTO: Mondelez International logo and stock graph are seen displayed in this illustration picture taken July 26, 2021. Picture taken July 26, 2021. REUTERS/Dado Ruvic/Illustration/File photo

By Jessica DiNapoli

NEW YORK (Reuters) -Food maker Mondelez, which manufactures brightly colored Sour Patch Kids and Swedish Fish candies, is actively working to switch to natural dyes for products that use synthetic colors, the company said in an email, without giving a time frame for the transition.

The Chicago-based company, which also makes Oreos and chocolate brands like Milka popular in Europe, said the work is in line with changing consumer preferences and local laws. In 2015, Mondelez said it would remove artificial colors and flavors in many of its brands by 2020.

U.S. Health Secretary Robert F. Kennedy Jr. has been pressuring food makers to ditch synthetic dyes by the end of next year. So far he and U.S. Food and Drug Commissioner Marty Makary have relied on voluntary commitments from companies rather than regulatory changes.

Mondelez had been an outlier among major packaged food companies because it had yet to make any commitments to change its formulations, unlike Jell-O maker Kraft Heinz and yogurt manufacturer Danone.

Kennedy and Makary have been urging the changes due to health concerns that link artificial colors to conditions such as ADHD and obesity, although scientists say that requires more study.

Sour Patch Kids and Swedish Fish are among the top 10 gummy candy brands in the U.S., according to market research firm Euromonitor.

Mondelez CEO Dirk van de Put said this year that the "Make America Healthy Again" movement backing Kennedy would put new cost pressures on the company, leading to price hikes for Americans. Some varieties of Oreos, such as a Halloween spooky colored crème version on retailers' shelves now, use synthetic dyes.

Some U.S. states have also passed laws banning dyes. West Virginia this year banned food for sale in the state with synthetic dyes starting January 1, 2028.

"The state level crackdown on food dye is motivating for these companies," said Thomas Galligan, a scientist at the Center for Science in the Public Interest. "It's a stronger motivator than the request for a voluntary phaseout from the FDA."

Galligan added that it will be challenging to keep track of whether food companies stick to voluntary commitments to phase out synthetic dyes because there is no thorough database tracking product formulas.

(Twitter: @jessicadinapoli; Editing by David Gregorio)