All Are Gluten Free. A fresh potato is gluten free. If a potato has been processed to create frozen foods, french fries or potato chips, it likely has had additives, so that it is no longer a gluten-free food.
Yes. Potatoes are naturally gluten-free, but processed potatoes (such as potato chips) may have picked up some gluten from wheat, barley, malt, or rye ingredients during the processing. One should always check the labels to see if they say "gluten-free".
Yes. Potatoes are a plant which does not make gluten. So they are gluten-free. Gluten free of course is only an issue if you have the inherited inability to digest gluten (about 8% of people). Otherwise this is being used inappropriately for healthy or natural and that is a meaningless connection. If you can digest gluten (92% of people) there is nothing to fear.