The designation of natural or artificial can be a rather arbitrary one. Is table sugar natural? It is processed (milled and chemically refined) from a plant like most sweeteners. Does “natural” mean you must find it outdoors without any changes? By this definition, unheated, unfiltered honey is natural, but many products including sucrose, corn syrup and fructose are not. They are all processed (changed) from their natural state to some degree.
https://www.naturallysweetkitchen.com/how-sugar-is-made-why-its-best-to-avoid/
Avoid processed anything as much as you can. Eat whatever is in season. However if you can't avoid Friday night pizza, that is quite understandable.
Sugars can be found in the human bloodstream as a natural product of our digestion and metabolism, your brain up runs on it. Aspartame, not so much.