Something Else That Can Cause Cancer

Many people take aloe vera supplements to stay healthy — more specifically to keep their guts healthy. But now, researchers at the US National Toxicology Program have found that too much of the extract can cause tumors in the intestines instead of keeping them healthy, reports New Scientist's Peter Aldhous. For the study, rats were given drinking water spiked with high doses of a whole-leaf extract of aloe over the course of two years. Nearly 40 percent of female rats and 74 percent of male rats given the spiked water developed tumors, both malignant and benign, in their large intestines, Aldhous says. The researchers say it's not yet clear what this means for people, and are designing and second round of experiments, but these could last for several years.