Clear Evidence of Aloe Vera Carcinogenic Activity
Aloe vera food supplements and drinks are supposed to help your gut stay healthy – or so herbalists claim. But now a warning flag has been raised by the US National Toxicology Program (NTP), which has found that rats given drinking water spiked with an extract of the succulent plant developed tumours in their intestines.
In the rodents given water containing 1.5 per cent by weight of a whole-leaf extract of aloe vera (Aloe barbadensis) over two years, 39 per cent of females and 74 per cent of males had malignant or benign tumours in their large intestines. None of these growths were seen in rats given pure drinking water.
Experiments to estimate the risks to people are likely to last several years. The first task is to establish which biochemicals within the complex mixture extracted from aloe vera are responsible for causing the rats’ tumours, says Nigel Walker of the National Institute of Environmental Health Sciences in Research Triangle Park, North Carolina, who evaluated the NTP results.
The prime suspect is a substance called aloin A, which together with other aloe extracts was removed from laxatives sold over the counter in US pharmacies in 2002, because manufacturers had failed to provide the FDA with sufficient information on safety.
In addition to promoting general health, some herbalists claim that aloe vera supplements can help treat conditions including asthma and diabetes – although the US National Center for Complementary and Alternative Medicine warns that there is not enough scientific evidence to support these uses.