http://whfoods.com/foodstoc.php
most of these foods have cancer fighting properties.. you have more of them in your diet and your %'s go down, simple as that.
also aspartame is one of the most tested food additives in history, if it was causing cancer than 80% of north america would have it, and they don't. does that mean you should drink 15 diet pepsi's a day? No, it isn't healthy, but doesn't mean it causes cancer either.
On top of that cancer rates have been falling steadily since the 1990's so no, it isn't happening to more people now, you are just noticing it more.