Does consumption of aspartame (NutraSweet) cause cancer?

Oooh boy, this topic is a doozy.  I had to do a lot of research to suss this out. Aspartame (NutraSweet, Equal, etc.) is a 0-calorie artificial sweetener that is used to sweeten about 6,000 common consumer products and has been in widespread use since the 1980's.  If you Google aspartame, you can find pictures depicting aspartame as a poison and the people eating it as zombies.  This is an exaggeration.  Aspartame has been subjected to thousands of studies in laboratory animals and in people.  Many small studies in rats have shown that consumption of aspartame can cause brain and liver tumors and leukemia/lymphomas (cancers of the blood). A roughly equal number of studies and experts show that aspartame does NOT cause cancers in rats.  A 2006 study conducted by the National Cancer Institute (NCI) followed about 500,000 people, recorded their aspartame consumption, and tracked whether these people later got cancer or not http://www.cancer.gov/cancertopics/factsheet/risk/aspartame .  The NCI study concluded that aspartame consumption did NOT increase the risk of any cancers, including leukemias, lymphomas, and brain cancer.   The FDA approved daily dose of aspartame is 50 mg/kg of body weight, or about 16 cans of diet soda for a 150-pound person.
So why all the controversy? Well, for one thing, did you know that laboratory research causes cancer in rats?  Yes, that's right, if you feed or inject rats with enough of anything, they will get cancer. Furthermore, Rats do not equal People.  We cure breast cancer in mice and rats all the time, but we cannot cure people yet. Just about anything is dangerous in high enough doses (even pure water!).
I'm sure the experts will continue to argue about aspartame for decades to come. The bottom line: aspartame probably isn't good for you (for this reason, and for others I will discuss in future posts), and you should limit your intake.  If you drink a diet pop or two everyday, you're most likely going to be just fine. There is no need for panicking and all those zombie pictures all over the internet. I for one am going to try to reduce my Diet Pepsi consumption, and I already think that foods made with aspartame (like Yoplait light yogurts) taste positively awful. If you like to limit your calories in things like coffee or tea, I recommend trying Stevia, which is an all-natural plant-derived sweetener.