There are many foods on the market that are made with chemicals most people know little to nothing about. This may seem bad, however with the technology available today it is easy to do a simple Google search and find out basic information about their food's ingredients. Companies that manufacture items meant to be consumed would have it in their best interest to not include harmful ingredients, because people would stop buying their products if they're known to be unhealthful. Food items for commercial sale are also regulated by the Federal Drug Administration (FDA), and sellers are required to provide information about their food's ingredients and sources. If a food was scientifically proven to 'kill you' it would be recalled by the FDA.
This argument is just semantics:
Artificial: imitation; simulated; sham
Natural: having undergone little or no processing and containing no chemical additives
Flavors: a substance or extract that provides a particular taste; flavoring
All from dictionary.com