Subway has joined the list of food companies dropping artificial ingredients. The sandwich chain, known for its marketing itself as a fresher alternative to hamburger chains, told The Associated Press it will remove artificial flavors, colors and preservatives from its menu in North America by 2017. Whether that can help Subway keep up with changing attitudes about what qualifies as healthy remains to be seen. Elizabeth Stewart, Subway's director of corporate social responsibility, said in an interview that improving the ingredients used 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.