I tried to reduce my sugar intake by using artificial sweetners containing Aspartame. Shortly after I started to get cluster headaches. I didn't know there was a possible link until I did some research. Trouble is that Aspartame turns up in many things you eat & drink (even in some brands of Co-codimol). I go for products that use Sorbitol instead. Look up 'Aspartame' & reach your own conclusions.