Dr Cohen: There have been lots of rumours and scares about sweeteners. Saccharine and cyclamate have reportedly been found to have carcinogenic effects on animals, but not on humans. Aspartame has also caused controversy in the past, but has been declared safe. 

There's an advised recommended daily amout not to exceed for each sweetener: 40mg for every kilo you weigh for aspartame, 9 mg by kilo for acesulfame and 2.5 per kilo for saccharine. Cyclamates are not used in food products, and are only authorised for use in the classic kind of artificial sweeteners you use in tea and coffee. Don't worry about exceeding the recommended limits: if you do the maths, you'll see you actually need to eat a ridiculous amount to go over the limit!