MSU research: Eating brown rice increases exposure to arsenic compared to white rice

(Press-News.org) Why this matters:

Arsenic levels in brown rice were found to be higher for U.S. consumers than in white rice, despite people often looking to brown rice as a healthier alternative. There is significant arsenic risk for U.S. children under 5 who consume brown rice, as arsenic is a toxic chemical element that can lead to health problems. Arsenic levels in U.S.-grown rice were found to be considerably lower than rice grown outside the country, suggesting there is concern to U.S. consumers who eat rice grown outside the country. EAST LANSING, Mich. – Whether you buy rice at the grocery store or order a side of it while dining out, do you prefer brown rice or white rice? Or do you exclusively choose brown rice over white rice because you want to eat healthier, as brown rice contains more nutrients and fiber? Well, the answer to this question is not as simple as you might have thought, as it ignores a potential food safety concern.

According to new research from Michigan State University, published in the journal Risk Analysis, brown rice was found to contain higher levels of arsenic content and inorganic arsenic concentration than white rice among American populations.

While there are no major health risks for the general American public, there are potential health concerns for infants and children under age 5, as they consume more food relative to their bodyweights than adults.

“This research is important because it acknowledges the importance of considering food safety along with nutrition when consumers make choices about food,” said senior investigator of the study Felicia Wu, John A. Hannah Distinguished Professor and University Distinguished Professor at MSU’s College of Agriculture and Natural Resources. “While we found that choosing brown rice over white rice would result in higher arsenic exposure on average, the levels should not cause long-term health problems unless someone ate an enormous amount of brown rice every day for years.”

Research background and methodology

Arsenic is a natural component of the earth’s crust, and it is highly toxic. When compared to other cereal grains, rice has significantly higher contents of arsenic. In fact, rice takes up nearly 10 times more arsenic content than other grains.

This is because rice is often grown in continually flooded paddies, and wet soil conditions favor arsenic being taken up from the soil into the plants.

While the nutritional benefits of brown rice are well documented, white rice remains to be consumed more both in the U.S. and throughout the globe.

Therefore, Wu, along with postdoctoral research associate and lead author Christian Scott, both in the Department of Food Science and Human Nutrition, compared the arsenic exposure and associated risks between brown and white rice for U.S. populations.

Specifically, after comparing the nutritional aspects of brown and white rice, Wu and Scott used data courtesy of the “What We Eat in America” database of the U.S. Environmental Protection Agency and Joint Institute for Food Safety and Applied Nutrition to calculate average daily intake mean rice values for both brown and white rice.

The results provided insight into the difference in arsenic levels between brown and white rice as well as more complex data regarding how levels differed by region, highlighting where and what populations may be at increase health risk.

Geographic arsenic differences

The inorganic arsenic concentration of white versus brown rice was considerably different by region. For rice grown in the United States, the researchers found the proportion of the more toxic inorganic arsenic in white rice was 33%, and in brown rice was 48%; whereas in rice grown globally, 53% of total arsenic in white rice was inorganic, 65% of total arsenic in brown rice was inorganic. Organic arsenic, more commonly found in seafood as well as in other foods, is less toxic because it is readily excreted from the body.

There are also some populations who are more vulnerable due to elevated rice consumption or susceptibility to arsenic exposure. Specifically, this includes young children, Asian immigrant populations and populations that face food insecurity.

The values researchers found did indicate a potential harmful risk of arsenic exposure from brown rice for children under age 5 and as young as 6 months.

Interpreting the results

It’s important to not interpret these findings as evidence that brown rice is unhealthy, or that you should now consume only white rice, Wu said. Brown rice does contain important ingredients such as fiber, protein and niacin, which all benefit consumers.

“This exposure assessment is only one side of the equation when examining the potential trade-offs between brown and white rice consumption,” Wu said. “Even if arsenic levels are slightly higher in brown rice than white rice, more research is needed to demonstrate if the potential risks from this exposure are mitigated in part by the potential nutritional benefits provided by the rice bran.”

The researchers suggest completing an empirical analysis of the cost and benefits to societal public health by consuming brown rice compared to white rice. In their manuscript, they document additional key differences between brown and white rice, including prices, overall nutritional benefit and environmental burden.

Potential policy changes

Chronic exposure to arsenic over a lifetime may increase cancer risk. Therefore, this research raises the question about consumer behavior and public health. If more consumers were aware about arsenic concerns, then they may intentionally make different dietary decisions, especially when it comes to rice consumption.

As water is already regulated, the Food and Drug Administration’s Closer to Zero initiative will soon set action levels for arsenic when it comes to food products based on risk assessment to the American population. It is important for all consumers to be aware of arsenic levels in their food and understand that brown rice is a major source.

As Americans try to eat healthily and look to incorporate higher-nutrition content choices in their diets, this study challenges the notion that these choices are simply black and white — or in this case, brown and white.

By Jack Harrison

Read on MSUToday.

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