Eating brown rice increases arsenic exposure compared to white rice, flags US study

Eating brown rice can lead to significant arsenic risk for children under five compared to white rice, according to research by Michigan State University (MSU) in the US. 

Arsenic is a natural component of the earth’s crust and is poisonous to humans and animals. Due to growing conditions, rice takes up nearly ten times more arsenic content than other grains. Rice is often grown in continually flooded fields, and wet soils can absorb arsenic favorably and transmit it to plants.

Brown rice is often considered a healthier carbohydrate choice due to its lower glycemic index value and high fiber content.

“This research is important because it acknowledges the importance of considering food safety along with nutrition when consumers make choices about food,” says senior investigator of the study Felicia Wu, who is 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.”

While the general public is usually safe from the health risks of eating brown rice, the research warns of potential concerns for infants and children under age five as they consume more food relative to their weight than adults.

Vulnerable populations at greater risk

The scientists also found that the inorganic concentration of white versus brown rice differs by region in the US. For example, for domestically grown rice, the proportion of inorganic arsenic (which is more toxic) in white rice was 33% and in brown rice was 48%.

In rice grown globally, 53% of the total arsenic in white rice was inorganic, whereas 65% of the total arsenic in brown rice was inorganic. The body readily excretes the less harmful organic arsenic, which is commonly found in fish and other foods.

Some US populations face a greater risk of arsenic exposure due to higher rice conception, including children, Asian immigrants, and food insecure individuals.

The researchers note that it’s important not to interpret the findings as evidence that brown rice is unhealthy or that it might be better to consume only white rice.

“This exposure assessment is only one side of the equation when examining the potential trade-offs between brown and white rice consumption,” says Wu.

“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.”

Policy push

The team recommends conducting a cost-benefit analysis for societal public health, comparing the two rice types in terms of price, environmental footprint, and nutrition for more comprehensive data.

Citing the link between chronic arsenic exposure and cancer risks, the research highlights the need for more consumer awareness to enable intentional dietary decisions, especially about rice consumption.

The US Food and Drug Administration is on track to set action levels for arsenic in food products based on risk assessment as part of the Closer to Zero campaign. The researchers assert that as US consumers embrace healthier foods and in the current policy landscape, their study challenges the idea that such choices are black and white.