SciTech

Science Q & A: Arsenic and more rice

Foods that contain rice, rice vinegar, routinely contain some level of arsenic, scientists say. But it is unclear how serious a health risk they pose.
Foods that contain rice, rice vinegar, routinely contain some level of arsenic, scientists say. But it is unclear how serious a health risk they pose. MCT

Q. I’ve read about unacceptable levels of arsenic in both brown and white rice. Are rice vinegar and rice crackers also affected?

A. Foods that contain rice, including rice crackers and vinegar, routinely contain some level of arsenic, scientists say, as do products such as rice cakes, rice wine and cereals, and snack bars and baking mixes that contain rice flour or bran. But it is unclear how serious a health risk they pose.

The Food and Drug Administration has a list of rice-containing foods that focuses on inorganic arsenic, considered the most dangerous form. One reason rice gets a lot of attention is that the plant is good at pulling inorganic arsenic from soil and water and storing it in the edible grain.

But levels of contamination vary according to the type of rice and where it is grown. Brown rice, for example, tends to show higher levels than white rice, which is stripped during processing of layers of the grain where arsenic tends to collect. California rice frequently contains less arsenic than that grown in Southern states, which tend to have higher levels of arsenic in the soil. Consumer Reports found that basmati rice from India, Pakistan and California had markedly lower levels of arsenic than other varieties.

The FDA found that arsenic levels ranged from 7.2 micrograms (a millionth of a gram) to 2.5 micrograms per serving. Rice crackers averaged about 5 micrograms. Rice vinegar was even lower, around 1 microgram or less.

“It may be that you get some dilution with the vinegar” or wine, said Brian Jackson, director of the Trace Metal Analysis Core Facility at Dartmouth College.

While these are all tiny amounts, inorganic arsenic has been linked to disease in extremely low doses. Much of this evidence comes from studies of arsenic in water. The federal Environmental Protection Agency sets a 10-parts-per-billion safety standard for drinking water.

Because of the complexities, it’s harder to assess risk from foods. “The question for everyone is: ‘Do I worry?’” Jackson said.

His recommendation: “If you are a person who is eating rice every day, and also snacking on rice products, then that 5 micrograms from rice crackers becomes significant,” he said. “The idea is to eat a varied diet, and be aware of how much rice you are eating.”

  Comments