Study shows prevalence of arsenic

By Jennifer Dalecki, The Dartmouth Staff

Published on Monday, February 20, 2012

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In the search for healthier food options, many people choose foods labeled “organic,” assuming that such products are both nutritious and free of toxins. However, a study by Dartmouth researchers published Wednesday in the journal Environmental Health Perspectives called attention to high levels of arsenic — linked to cancer, chronic diseases and negative developmental effects — in foods listing organic brown rice syrup, a common substitute for high-fructose corn syrup, as a primary ingredient. The tested foods included 17 infant formulas.

“We noticed products containing organic brown rice syrup often had very high concentrations of arsenic,” study co-author and earth sciences post-doctoral researcher Vivien Taylor said. “This led to a study of foods such as infant formulas, cereal bars and energy foods, which use organic brown rice syrup. These foods tend to be marketed to health-conscious consumers who would unintentionally be exposed to a known carcinogen.”

Concentrations of arsenic in some products were above the Environmental Protection Agency standard of 10 parts per billion for drinking water, according to the study.

Past studies by Dartmouth researchers and others have identified arsenic consumption through rice, an observation which spurred the rice syrup study by the Dartmouth Superfund Research Program, which included Kathy Cottingham, Margaret Karagas, Tracy Punshon, Taylor and lead author Brian Jackson. The team concluded that foods containing organic brown rice syrup as a primary ingredient can be a significant source of arsenic.

“By publishing these results, we hope that U.S. food standards authorities will set guidelines for arsenic in food,” Punshon, a research assistant, said. “We want to see that manufacturers using products containing processed forms of rice begin to measure the arsenic concentrations of these ingredients routinely.”

Researchers examined 17 infant formulas, 29 cereal bars and three types of energy drinks purchased from Upper Valley stores. Using plasma mass spectroscopy at the Trace Element Analysis Core facility at the College, the team compared food products containing organic brown rice syrup with similar products that did not use the syrup. The report did not specify which product brands were tested.

Of the 17 toddler formulas tested, two listed organic brown rice syrup as a main ingredient. These formulas — one dairy-based and one soy-based — were found to have arsenic concentrations 20 times greater than the formulas made without organic brown rice syrup. The concentration of inorganic arsenic averaged 8.6 parts per billion for the dairy-based formula and 21.4 parts per billion for the soy-based formula.

High arsenic concentrations in infant formula are greatly concerning, Jackson said. EPA standards for drinking water are set for full-grown adults, so the impact of these arsenic levels might be far greater for infants due to their low body weight and developing brains, he said.

“Ideally, levels for arsenic in infant formula should at least be at the drinking water level, but lower levels would probably be advisable,” Jackson said.

The researchers also examined cereal bars and energy products obtained from local markets. Twenty-two of the cereal bars listed one of four rice products — organic brown rice syrup, rice grain, rice flakes or rice flour — in the first five ingredients.

Like infant formula, cereal bars and high-energy foods containing organic brown rice syrup also had higher arsenic concentrations than those that did not contain the syrup. The cereal bars that had no rice-based ingredients ranged from 8 to 27 parts per billion of arsenic, while those containing a rice ingredient ranged from 23 to 128 parts per billion.

Compared to the potential problems with infant formula, there is minimal risk associated with eating a cereal bar every few days, according to Jackson.

Nevertheless, the research team and other biologists agree that the arsenic concentrations in foods necessitate more research as well as changes in food standard regulations.

“We need to know more about what we eat and drink,” biology professor Rob McClung said. “Hopefully we will start testing foodstuffs for contaminants — not necessarily all foodstuffs — but where scientific research suggests there are issues.”

Research professor Celia Chen suggested the potential for new research exploring the specific health effects of arsenic exposure through food and a means to limit arsenic uptake by plants.

Since the study’s publication, media and concerned parents have given its findings a great deal of consideration, according to Jackson.

“The attention is flabbergasting,” she said. “I hope that this response will be positive in helping set much needed guidelines and regulations.”