'Surprised to see aloe vera on the same list as lead, welding fumes and engine exhaust,' commented another. The cactus-like aloe vera plant has been used for centuries in traditional medicine, with ancient Greeks and Romans applying the translucent inner pulp to wounds. The global aloe vera extracts market is work roughly £1.2 billion – with demand rising every year. In 2013 researchers studying the toxic effects of aloe vera gave rats water containing varying concentrations of 'aloe vera whole-leaf extract', which contains aloe vera latex, for two years. Scientists believe compounds in aloe vera latex known as anthraquinones – which have a laxative effect and irritate the digestive tract – are responsible.