Yes, it is true that brown rice has been consistently found to contain arsenic. The U.S. Food and Drug Administration (FDA) has recently tested over 1,000 rice-containing products, including rice milks, rice crackers, rice cereals, brown rice syrup, and, of course, rice itself. Consumer Reports™ has also tested over 225 rice products commonly sold in U.S. supermarkets or online. Some manufacturers of rice products — including organic rice cereals and organic rice — have also done extensive testing on their product lines. All products tested have shown some amount of arsenic, regardless of the rice type and regardless of the growing conditions (organic versus non-organic). In the paragraphs below we will give you key information about arsenic and rice together with our recommendations for keeping this grain in your diet.

How contaminated with arsenic is rice?

As mentioned above, all rice products tested for arsenic appear to contain some of this heavy metal. The overall range for arsenic in rice products has been approximately 0.1-10.0 micrograms of arsenic per common serving size. See below to understand how this range compares to standards set for arsenic in food.

What standards have been set for safe intake of arsenic from food?

Government agencies in the U.S. have yet to set official standards for safe intake of arsenic from food. Other organizations have, including the Joint FAO/WHO Expert Committee on Food Additives (JECFA), which set a limit of 200 micrograms per kilogram of polished rice as the maximum safe level for this food. At WHFoods our cup of cooked brown rice weighs 195 grams or approximately 20% of one kilogram. This amount of brown rice would not be allowed to contain more than 39 micrograms of arsenic according to the JECFA guideline. To give you one quick comparison, Lundberg Family Farms based in Richvale, California, has found approximately 2-6 micrograms of arsenic in its different types of rice (white, brown, aromatic, non-aromatic, long grain, short grain, and medium grain). This amount would represent about 5-15% of the JECFA guideline. It is worth noting that the Codex Alimentarius Commission (Codex) has also set this same limit of 200 micrograms per kilogram of white rice.

One final note about regulation of arsenic in water versus food: the U.S. Environmental Protection Agency (EPA) regulates the amount of arsenic allowed in drinking water and has set the current maximum contaminant level at 10 parts per billion of arsenic, or 10 micrograms per liter.

How does rice become contaminated with arsenic?

Approximately half of the arsenic found in rice comes from water used in rice cultivation and the other half comes from the soil. Rice is unusual as a food crop because the paddy soil culture used to grow it can create an anaerobic (oxygen-free) environment that allows more uptake of arsenic into the plants. (Grains like wheat, which grow tall and well up into the air, are aerobic-growing plants.) In some comparison studies rice is able to uptake as much as ten times more arsenic than other grains.

Of course, the explanation above still does not explain how arsenic gets into the water and soil used for rice growing. Some of this arsenic is naturally occurring as an earth element. However, there are also some human-created problems involving arsenic. Arsenic-containing pesticides remain legal for use in the U.S. and can be a source of environmental contamination. Preservatives used for treating wood can also contain arsenic. Both of these sources can eventually make their way into the soil and groundwater. Arsenic can be a contaminant in poultry litter and poultry manure which are sometimes used as crop fertilizers. Some FDA-approved animal drugs may also contain arsenic. (However, most of these drugs are being voluntarily removed from the market by their manufacturers.) When arsenic gets introduced into the general environment it can contaminate any food. However, few foods appear to uptake arsenic at the same rate as paddy rice.

Does arsenic always pose a health hazard?

Researchers usually draw a distinction between inorganic and organic arsenic and they point to inorganic arsenic as the most hazardous to our health. The two basic forms of inorganic arsenic are arsenite (called "trivalent") and arsenate (called "pentavalent"). The trivalent forms pose a greater health hazard because they are more reactive. In addition, when arsenite is converted into arsenate reactive oxygen species (ROS) are created and their creation can lead to additional unwanted chemical reactions. Some examples of organic arsenic include arsenocholine, arsenobetaine, monomethylarsonic acid, monomethylarsonous acid, and arsenosugars. Because our body has the ability to eliminate these organic forms of arsenic more readily, researchers usually focus on the inorganic forms of arsenic as more problematic. It is also worth noting here that the Agency for Toxic Substances and Disease Registry (ATSDR) at the U.S. Department of Health and Human Services (DHHS) publishes a list every two years identifying the top 275 highest priority toxic substances in the U.S. Arsenic was the number one toxic substance in 2013, ranked significantly higher than the number two (lead) and number three (mercury) substances.

How does brown rice compare to white rice?

Brown rice typically contains more arsenic than white rice since arsenic is better retained in the outer pericarp and aleurone layers of the rice. These layers are retained in brown rice rather than being polished off of the grain.

Are there ways to lower arsenic levels in rice?

Yes, there are two proven ways to reduce arsenic levels in rice. The first way is to thoroughly rinse the rice before cooking. About 10-25% of the arsenic can often be removed from the rice in this way. We encourage you to use this approach!

A second way to reduce arsenic in rice is to cook it "pasta style." This approach uses a 6:1 ratio of water to rice for boiling. (In others words, 6 cups of water for every cup of dry rice.) About 20-45% of the arsenic in rice can be removed using this second method. We see this second method as more controversial than rinsing, however. While it is true that a significant amount of arsenic can be removed in this way, "pasta style" cooking of rice also removes health-supportive nutrients from the rice, including numerous B-vitamins. For diets with borderline B vitamin content, this trade-off between arsenic removal and B-vitamin removal may not be worthwhile. So we believe that decisions about use of this second method need to be made on an individual basis.

Rice, Arsenic, and Portion Control

With the availability of brown rice in the marketplace containing 5-15% of public health guidelines for arsenic per serving, we believe that there is room for many people to continue consuming brown rice by practicing good portion control and making sure that brown rice is part of a varied diet. Loading up your plate with three cups of brown rice — or not even knowing how much brown rice you put on your plate — is very different than consuming one measured cup. If you have never measured out one cup of cooked brown rice in a measuring cup, we believe it is very worthwhile to do so!

A Final Note About Brown Rice, Arsenic, and Children

Several public health agencies in countries outside of the U.S. have set a lower standard for arsenic in rice products intended for children versus adults. These products include baby cereals containing rice, baby crackers containing rice, and rice itself. For example, in the United Kingdom a level of 100 parts per billion (ppb) is set for children's rice products, as compared to 200 ppb for rice products consumed by adults. Due to this tighter guideline a substantial number of children's rice products in the marketplace have been shown to exceed the acceptable limit. For us, this set of events in other countries suggests that parents of babies and young children may want to approach decisions regarding arsenic and brown rice differently than they would approach them in their own meal plan, and may want to consult with their pediatrician or healthcare provider when deciding on the best steps to take.

References

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