A sweetener commonly found in diet drinks and chewing gum has been added to the World Health Organisation's list of possible carcinogens - but you may not have to kick your Diet Coke habit just yet.<br /><br /><br />Josephine Franks<br />Sky News reporter @jos_franks<br /><br />Aspartame, a sweetener commonly found in diet drinks and chewing gum, has been declared a potential cancer risk by the World Health Organisation (WHO).<br /><br />The sweetener has been listed as "possibly carcinogenic to humans".<br /><br />The International Agency for Research on Cancer (IARC), the WHO's cancer research arm, said there was "limited evidence" aspartame caused cancer in humans.<br /><br />"While safety is not a major concern at the doses which are commonly used, potential effects have been described that need to be investigated," the WHO's Dr Francesco Branca said.<br /><br />And giving advice to the public, he added: "If consumers are faced with the decision of whether to take cola with sweeteners or one with sugar, I think there should be a third option considered - which is to drink water instead."<br /><br />Analysis: How concerned should you be?<br /><br />If there's limited evidence, why has the WHO made this declaration?<br /><br />The scale used by the IARC indicates the level of evidence there is for a substance being carcinogenic.<br /><br />The IARC uses four categories: 1 - causes cancer; 2A - probably causes cancer; 2B - possibly causes cancer and 3 - no evidence available on cancer risk.<br /><br />Aspartame was classified as 2B, "possibly carcinogenic", on the basis of limited evidence for cancer in humans (specifically hepatocellular carcinoma, a type of liver cancer).<br /><br />Other possible 2B carcinogens in the group include aloe vera, bracken ferns, lead and working as a hairdresser.<br /><br />The scale does not say how much exposure you need to raise your cancer risk - it just identifies the substances as hazards.<br /><br />Alice Davies, health information manager at Cancer Research UK, told Sky News: "Something being classed as a carcinogen doesn't tell you how much it could increase the risk of cancer.<br /><br />"Sometimes there are things that might cause cancer in theory, but in reality the dose that you're exposed to is too low to increase your risk.<br /><br />"So, for example, processed meat and smoking are both carcinogens but smoking causes about 54,000 cases of cancer in the UK each year whereas processed meat only causes about 5,400."<br /><br />So how much aspartame can I have a day?<br /><br />This is where another arm of the WHO comes in, the Joint WHO and Food and Agriculture Organisation’s Expert Committee on Food Additives - JECFA for short.<br /><br />JECFA reviewed the data on aspartame consumption and said adults can safely consume up to 40mg per kilo of body weight.<br /><br />This does not change the daily limits recommended previously.<br /><br />That means an adult who weighs 70kg could consume 2,800mg of aspartame a day.<br /><br />Aspartame is found in drinks including Coke Zero, Diet Coke, Diet Pepsi, Pepsi Max, Sprite Zero and Fanta Zero.<br />
