It's important to note, though, that while many non-dairy creamers don't contain lactose -- which is the sugar found in milk that some people have a hard time digesting -- that they still might contain casein, which is a milk protein that can affect people with milk allergies. The good news is that if you are allergic to milk or have eliminated dairy products from your diet, there are numerous types of plant-based coffee creamer on the market that you can still enjoy.