Eating aromatic rice reduces arsenic exposure

Exposure to environmental arsenic (As) is a worldwide issue, especially in locations where rice is the main calorific content in the diet. Eating aromatic rice reduces environmental arsenic intake, according to results published in the journal of Biomedical Spectroscopy and Imaging using high performance liquid chromatography coupled with inductively coupled plasma–mass spectrometry (HPLC–ICP–MS).

Dr Pavaz Haris from De Montfort University (Leicester, UK) is leading research into reducing human exposure to arsenic, by finding methods to remove it from drinking water and the diet. In collaboration with Dr Michael Watts from the British Geological Survey (Nottingham, UK), the team investigated the effect of soil type on the levels of arsenic in rice.

The scientists analysed varieties of rice cultivated in the greater Sylhet region of Bangladesh where groundwater arsenic levels are reported to be lower than other regions of the country. Approximately 98 rice samples were collected and analysed using HPLC and ICP–MS.

The analysis showed lower levels of arsenic in rice from the greater Sylhet region than other regions of Bangladesh. Additionally, arsenic concentrations were lower in aromatic rice compared with non-aromatic rice. This is thought to be because of the dependence of non-aromatic rice on groundwater irrigation, whereas aromatic rice is grown in the wet season.

Furthermore, rice in the region had higher levels of the essential nutrients selenium and zinc. According to Dr Haris, the finding is important as consumption of certain types of aromatic rice will not only reduce arsenic exposure, but also increase zinc and selenium intake.

According to their research, for elements of the population consuming 500 g of rice a day in Bangladesh, intake of arsenic would be reduced by up to 69% if they switched to an aromatic rice variety from the greater Sylhet region. This is based on comparisons between different geographical areas.

“We seem to have found one of the lowest arsenic-containing rice ever reported in the literature,” said Dr Haris. “Several varieties of Sylheti aromatic rice even had lower arsenic than the well-known Basmati aromatic rice from India and Pakistan.”

The research has implications for populations in the western world. The type of rice identified could be used in infant foods, and to benefit those dependent on rice-based food because of allergies, according to Haris. He states that “it is essential that further research on aromatic rice from different parts of Bangladesh and other regions of the world are conducted.”

Reference:

1. S.W. Al-Rmalli, R.O. Jenkins, M.J. Watts and P.I. Haris, Biomedical Spectroscopy and Imaging DOI:10.3233/BSI-120028 (2012).

This story originally appeared in The Column. Click here to view that issue.