This acid is so strong you can clean a toilet with it or dissolve a tooth in 48 hours. Says Janet Thorn, senior lecturer in nutrition at Oxford Brookes University. I think the presence of caffeine is slightly sinister because it s added as a stimulant, says Ian Shaw, Professor of Toxicology at Central Lancashire University. Caramel is widely used in soft and alcoholic drinks, sauces and canned meats. There have been suggestions that it is carcinogenic and causes white blood cell problems in animal tests.
Sodium benzoate stops contamination by microbes.
It s considered safe, although there have been claims that it provokes allergies, asthma and skin reactions. It is definitely toxic to cats. Colas are basically an expensive way of buying sugared water, says Janet Thorn. Thirty years ago, the British Common Cold Research Unit closed - in despair of finding a cure. And zinc compounds, in special lozenges, seem to settle in these canyons and prevent the virus from sticking to human cells.