The truth and the rumors for each sweetener are summarized here:

Saccharin (aka “Sweet’N Low): Although huge amounts given to rats may cause bladder cancer, there is no proof of cancer in humans.

Sucralose (aka Splenda):  Relation to DDT and to autoimmune disease is not true.  There is no proof of any adverse effect.

Acesulfame-K: Never been proven to cause cancer.

Aspartame (aka Nutrasweet, Equal):  Some say that its metabolism to methanol can make one prone to multiple sclerosis, Alzheimer’s, lupus, cancer, and seizures.  In fact, less methanol is produced from the metabolism of aspartame than from many fruits and vegetables.  Some people get headaches from aspartame.  And of course, it is neurotoxic to patients with phenylketonuria.   .  

(Prescriber’s Newsletter 2006; 13(2):10.)     – H.T.