Arsenic in rice causes genetic damage
Over the past few years, researchers have reported high concentrations of arsenic in several rice-growing regions around the world.
Now, University of Manchester scientists working in collaboration with scientists at CSIR-Indian Institute of Chemical Biology in Kolkata, have proved a link between rice containing high levels of arsenic and chromosomal damage, as measured by micronuclei in urothelial cells, in humans consuming rice as a staple.
The researchers discovered that people in rural West Bengal eating rice as a staple with greater than 0.2mg/kg arsenic showed higher frequencies of micronuclei than those consuming rice with less than this concentration of arsenic.
‘Micronuclei’
The study, published in Nature Publishing Group's Scientific Reports, looked at the frequency of ‘micronuclei’ a tell-tale sign of chromosomal damage (that has been shown by others previously to be linked to cancer) by screening more than 400,000 individual cells extracted from urine samples from volunteers.
The team, funded by the UK India Education and Research Initiative (UKIERI), chose a study population with relatively similar dietary and socio-economic status that was not otherwise exposed to arsenic, for example, through drinking water.
They demonstrated that the trend of greater genetic damage with increasing arsenic in rice was observed for both men and women, for tobacco-users and non-users, and for those from three different locations within the study area. The pattern observed was broadly similar to that previously seen for people exposed to arsenic through drinking high-arsenic well waters, which has caused devastating health impacts, including cancers, in many parts of the world.
‘Considerable concerns’
The authors say their work raises considerable concerns about health impacts of consuming high-arsenic rice as a staple, particularly by people with relatively poor nutritional status – which could perhaps be as many as a few hundred million people.
How directly relevant the results are to people in the UK, with a generally lower consumption of rice and better nutritional status, remains to be fully determined but is an obvious focus for further research, state the academics.
Professor David Polya, who led the Manchester team in the University's School of Earth, Atmospheric and Environmental Sciences, said: “Although concerns about arsenic in rice have been raised for some time now, to our knowledge, this is the first time a link between consumption of arsenic-bearing rice and genetic damage has been demonstrated.”
