My 37-year-old husband recently had suffered from racing heart beat twice in two weeks. When I was checking out your website for stuff to do with our daughter I happened to find the info on heart palpitations etc and straight away remembered seeing empty [yellow extruded flavoured snack with flavour enhancer 631] packets in his workbag! The racing heart beats came in bursts of maybe 5 to 10 seconds, 2-3 times an hour, a few hours after eating 631. It even happened when sitting down under no exertion. An ECG ten years ago showed his heart was fine. Since seeing your information, my husband hasn't had any more of those snacks or heart irregularities. – by email, Qld