Well, we do know that it's during cellular reproduction when DNA is copied, that genetic mutations most often happen. So in theory, anything that our body can m

Well, we do know that it's during cellular reproduction when DNA is copied, that genetic mutations most often happen. So in theory, anything that our body can metabolize, is carcinogenic in the sense that energy intake fuels cell growth/reproduction. In other words, eating causes cellular growth -> which causes DNA to be copied -> which increases the chances of mutations occurring from DNA replication -> which increases the chances of cancer occurring. Aspartame is broken down to aspartic acid and phenylalanine which your body does metabolize so yes, it could theoretically increase the chances of cancer occurring in this way. But then again, almost everything is carcinogenic in this sense - even breathing oxygen. Perhaps it would be helpful if we start considering what substances are more or less carcinogenic, rather than merely asking whether they are carcinogenic at all. Along that thinking, I'd wager that aspartame is probably less carcinogenic than say, sugar.