Brown rice may contain toxic arsenic levels, study shows
Brown rice -- and anything made with brown rice syrup --could be a source of potentially toxic arsenic, according to research by scientists at Dartmouth College.
The research, which was published in the Proceedings of the National Academy of Sciences (PNAS) shows that rice may be a greater source of arsenic. It is common in groundwater, but now, the threat has extended to rice, as it is able to take the arsenic from its environment into the rice plant.
The research team found that dangerous amounts of arsenic were in organic powdered toddler formula whose top ingredient was brown rice syrup, ABC reported. The formula contained six times more arsenic than the Environmental Protection Agency considers safe for the water supply, they reported.
Dartmouth environmental chemist Brian Jackson and his colleagues also reported elevated arsenic levels in some brown rice-sweetened cereal bars, energy bars and energy "shots"consumed by endurance athletes, according to a study published today in the journal Environmental Health Perspectives, ABC reported.The results do not identify any products by name, they added.
Dartmouth said in its research that though arsenic is found naturally in the environment, elevated concentrations can be harmful to humans. The World Health Organization set guideline limits for Arsenic levels in drinking water (currently 10 micrograms per liter).
“Arsenic exposure during pregnancy is a public health concern due to potential health risks to the fetus,” Margaret Karagas, professor of community and family medicine at Dartmouth Medical School and senior author of the paper, told the Dartmouth Now, a publication at the school.
Karagas is director of the Children’s Environmental Health and Disease Prevention Center at Dartmouth.
She said that outside research has related arsenic at very high levels to infant mortality, reduced birth weight, slowed immune function, and increased mortality from lung cancer later in life.
The U.S. Department of Agriculture says that Americans, on average, eat half a cup of rice every day. The numbers, however, are different based on ethnic groups—Asian Americans consume an average of two cups a day.
“The study presented in the PNAS paper is based upon a sample of 229 pregnant New Hampshire women whose urine was tested for arsenic concentration,” says Diane Gilbert-Diamond, a postdoctoral fellow and co-lead author on the paper, according to Dartmouth Now. The women were divided into two groups based on if they ate rice two days before urine collection.
After testing the tap water in their homes for arsenic, the women were tested. Urinary arsenic concentrations for the 73 study subjects who ate rice showed an average of 5.27 micrograms per liter, while the median for the 156 non-rice eaters showed 3.38 micrograms per liter, the Dartmouth study said.
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