Report of arsenic in rice products alarming, but doctors urge calm
About two weeks ago, Deb de Moulpied went to the Concord Food Co-op for her groceries and, as she often does, asked for more information about where the food she was buying came from.
Just a few days before, she read about a study in the November issue of Consumer Reports concerning levels of arsenic in rice, particularly rice grown in the Mississippi Delta, where soils were contaminated by arsenic-based pesticides years ago.
The clerk assured her the rice she was considering was organically grown in California by Lundberg Family Farms.
A few days ago, de Moulpied said, her jaw dropped as she saw a New York Times feature on the same California rice farm, battling arsenic in the soil that was contaminating its rice.
“I don’t know what I’m going to do next time,” de Moulpied said. “I’ll still want to know where it comes from, and what I buy won’t be from Lundberg, it won’t be from Mississippi.”
As far as how concerned she is about the rice she already has, de Moulpied was philosophical.
“Is arsenic dangerous? Yeah, it’s a known human carcinogen. Does the dose make the poison? Yes. What is the threshold where you go from a little is no big deal and a lot is? We don’t know. We don’t what we don’t know,” she said.
The Consumer Reports study showed that rice and rice-based products such as cereal and rice syrup contained levels of inorganic arsenic above the federal limit for arsenic in drinking water. Inorganic arsenic is considered much more toxic than organic arsenic.
The Environmental Protection Agency limits arsenic in public drinking water supplies to 10 parts per billion, or ppb. But some research indicates that prolonged exposure at that level may cause health effects, including bladder and lung cancer. New Jersey set a more stringent limit of 5 ppb.
A team of researchers at Dartmouth has been studying arsenic exposure and its effects in pregnant women and infants for several years as part of the New Hampshire Birth Cohort Study, and wrote about arsenic in rice last year. About two-thirds of the women and children participating in the study live in or around Concord, according to Carolyn Murray, assistant professor of community and family medicine and of the Dartmouth Institute.
Rice is a staple of the Asian and Latin American diet, and for the growing number of people with celiac disease or gluten intolerance.
“It’s a really important grain, and it’s inexpensive. It’s a staple from a cultural standpoint, and from a stability standpoint. In places like Southeast Asia, they don’t have other grains, but they are able to grow this, and grow it inexpensively,” she said.
As scientists studied arsenic in water, their attention turned to rice, often grown submerged in water and very efficient at absorbing water and minerals into the edible part of the plant, she said.
The 2011 Dartmouth study tested the urine of 229 pregnant New Hampshire women. The women in the study were divided into two groups based on whether they had eaten rice in the two days before urine collection. The tap water in their homes also was tested for arsenic concentration, to separate the potential for exposure from drinking water from rice.
Women who ate rice in the days before the test consistently showed higher levels of arsenic in their urine. Further studies haven’t been done yet to examine what health effects the exposure could cause.
Consumer Reports went one step back in the timeline, testing rice itself: 223 samples of various rice products, including infant cereals, hot cereals, ready-to-eat cereals, rice cakes and rice crackers. The highest amount of inorganic arsenic was 568 ppb, in Della Basmati Brown Rice grown in Arkansas.
The Consumer Reports study of the rice itself has raised a variety of reactions from different corners of the medical community.
While one Boston pediatrician with a blog on the Boston Globe website wrote earlier this month that she’s telling parents to stop feeding rice cereal to babies and cut back on rice for all children, several others, including the chief physician at Mass General Hospital for Children, said they are taking a wait-and-see approach.
Dr. Ronald Kleinman is also chief of the Mass General Hospital gastroenterology and nutrition unit.
“We’ve known for a very long time that these trace minerals are present in most of the vegetables that we eat,” he said. “They are present in the soil. . . . The real question is whether there is harm from this, and there is no immediate harm. You don’t get immediately poisoned at those levels, so this gives us some time to get another company or magazine to weigh in on this with their own analysis.”
Infant cereals, usually made from rice refined to remove the hull, showed between 97 and 330 ppb.
“It’s reassuring, but I know it’s not perfect,” he said, but he has not told any parents to change their habits, as long as they were good habits to start with.
No parents have brought the issue up to Dr. Patricia Edwards at Concord Pediatrics.
“It’s interesting because once these things come out, we usually get a million phone calls,” she said.
Like Kleinman, she hasn’t advised parents to ban or limit rice for children. Like the scare about nitrates in hot dogs several years ago, moderation is key, she said.
“Kids should not be eating hot dogs every day anyway. That helps eliminate a lot of the concern, just a balance,” she said.
“There is always room for common sense,” he said. “There are other grains you can use: oats, wheat, corn. And it’s not necessary to only feed cereal as first foods. The nutrition from poultry, meat and fish is actually at least as good if not better than what you’ll get out of cereal. Your child should not be eating rice cereal three times a day.”
Federal data cited by Consumer Reports showed that some infants, however, do eat up to two or three servings of rice cereal daily, and at that rate, could be exposed to twice as much arsenic as considered acceptable by the federal government.
“This is the challenge about the science of food sources of arsenic,” Murray, at Dartmouth, said. “We are at the very beginning of understanding the ways in which you are exposed to it, and ways of measuring arsenic reliably in food sources is just really being mastered.”
More research is available on the effects of arsenic in drinking water, and more reliable testing methods have been developed to check water than food, she said.
In the 1980s and ’90s, wells in Bangladesh were tested after residents began developing skin lesions. Naturally occurring arsenic was found in more than half the wells tested, at levels greater than 50 ppb. Many residents of the area also later developed cancer in their lungs or bladders.
Infant mortality, low birth weight and immune system problems are also connected to high levels of arsenic-contaminated water exposure, Murray said.
Arsenic tests are not required for real estate sales, and unless they’re specifically requested, often go undone, she said.
“What’s most important is a balancing of the research,” she said.
“We are early in our understanding of where dietary arsenic in our food is and how it relates to our health, but we do know a lot about drinking water. That should be the important message for anyone from stories about arsenic. Get your well tested.”
(Sarah Palermo can be reached at 369-3322 or
firstname.lastname@example.org or on Twitter @SPalermoNews.)