Sandwich chain Subway is once again responding to food activists in their latest campaign seeking to eliminate artificial ingredients from their products.

On Friday, a representative for the Subway fast food franchise told the Associated Press the company plans to live up to its "eat fresh" promise by altogether ridding their North American menu of "artificial flavors, colors and preservatives" by 2017.

AP has the details:

Elizabeth Stewart, Subway's director of corporate social responsibility, said in an interview that ingredient improvement has been an ongoing process over the years. More recently, she said the chain has been working on removing caramel color from cold cuts like roast beef and ham. For its turkey, Subway says it plans to replace a preservative called proprionic acid with vinegar by the end of this year.

Among its toppings, Stewart said Subway is switching to banana peppers colored with turmeric instead of the artificial dye Yellow No. 5. Without providing details, she said the chain is also working on its sauces and cookies.

Yellow dye no. 5 "may be contaminated with several cancer-causing chemicals," a 2010 study from the Center for Science in the Public Interest found.

"In addition, Yellow 5 causes sometimes-severe hypersensitivity reactions in a small number of people and might trigger hyperactivity and other behavioral effects in children," the study added. "Posing some risks, while serving no nutritional or safety purpose, Yellow 5 should not be allowed in foods."