With reports of arsenic found in rice in 2012 and most recently this month, there has been much concern about how safe it is to eat rice. I’m going to address those concerns.
Plants readily absorb arsenic from the soil. According to John M. Duxbury, PhD, a professor of soil science and international agriculture at Cornell University, “All plants pick up arsenic. Concentrations in leaves of plants are much higher than in grains of plants. Thus, leafy vegetables can contain higher levels of arsenic than rice, especially when they are grown on arsenic-contaminated soils.”(1) He indicates that our arsenic intake is low because he assumes that we eat a much lower volume of leafy greens compared to other foods. Rice grows in water (paddies), making it more vulnerable to arsenic contamination because arsenic dissolves easily in water, which allows rice to take up and store more arsenic than plants grown in drier soils.(1,2)
Plants readily absorb arsenic from the soil. According to John M. Duxbury, PhD, a professor of soil science and international agriculture at Cornell University, “All plants pick up arsenic. Concentrations in leaves of plants are much higher than in grains of plants. Thus, leafy vegetables can contain higher levels of arsenic than rice, especially when they are grown on arsenic-contaminated soils.”(1) He indicates that our arsenic intake is low because he assumes that we eat a much lower volume of leafy greens compared to other foods. Rice grows in water (paddies), making it more vulnerable to arsenic contamination because arsenic dissolves easily in water, which allows rice to take up and store more arsenic than plants grown in drier soils.(1,2)
Arsenic occurs naturally in some minerals and is found in soils that eroded from rocks containing those minerals. It has been shown that arsenic content in soil is higher around rivers and that clay soils have more naturally occurring arsenic(1). For example, arsenic levels are high along southern parts of the Mississippi river.(3) Arsenic is also abundant in soils in some areas due to the use of arsenic-containing pesticides. Rice paddies in the south-central region of the U.S. replaced cotton fields where cotton farmers used arsenic-based pesticides to control the boll weevil beetle, and those soils have higher levels of arsenic.(1,2) According to a map of arsenic in surface soil produced by the U.S. Geological Survey, rice producing areas in Louisiana, Mississippi, Arkansas and Missouri have the highest levels of arsenic in the top soil, while rice producing areas in California and Texas have much lower levels of arsenic in the top soil.(3) When Consumer Reports tested 223 rice products in 2012, they found that in the U.S., the highest levels of arsenic was detected in rice from Missouri, Arkansas, Louisiana, and Texas.(2) The lowest levels found in the U.S. were detected in rice grown in California.(1) Scottish researchers found that basmati and jasmine rice from Thailand or India has lower levels of arsenic than rice grown in the U.S.(1)
Arsenic concentrates in the outer layers and the germ of the rice grain. Once the inedible husk is removed, leaving brown rice, the milling and polishing processes remove the outer layers of the brown rice to produce white rice. As a result, more arsenic remains in brown rice than in white rice.(1,2)
Just last week on September 6, 2013, the FDA released the analytical results of 1,300 samples of rice and rice products (1,100 new samples and 200 samples tested in 2012) as part of a major effort to understand and manage possible arsenic-related risks associated with the consumption of these foods.(4) According to the FDA report on Arsenic in Rice and Rice Products:
“The levels FDA found in its testing are too low to cause immediate or short-term adverse health effects. FDA’s work going forward will center on long-term risk and ways to manage it with a focus on long-term exposure.”(4)
In other words, they’re saying that it’s okay to eat rice and rice products at this point, which can change in the future once they've collected more data. However, they are recommending that alternatives to rice cereal be considered for an infant’s first solid food.(5)
There are two main forms of arsenic: inorganic and organic, and there are several species of each. Inorganic arsenic is of the most concern because it’s toxic; organic arsenic is less toxic.(1,2,3) However, the extent of toxicity of organic arsenic is not fully understood. Scientists at the FDA and in academic laboratories are developing new methods and improving old ones for identifying and quantifying arsenic in its various forms.(3) In the meantime, arsenic levels are reported as total arsenic (in parts per billion, ppb) and inorganic arsenic (ppb and in micrograms per serving; a serving of rice is 45 grams dry, about 1 cup of cooked rice). The FDA found varying levels of inorganic arsenic levels in rice ranging from 2.6 – 7.2 micrograms per serving, with instant rice (the most processed) being the lowest and brown rice being the highest.(4) These results are consistent with the 2012 Consumer Reports study.(2) While I didn’t find it indicated in the data that was just released last week, both the original FDA study of 200 samples and the Consumer Reports study of 223 samples showed that rice from the southeastern U.S. (rice and rice products) have higher levels of arsenic than rice from California.
Although the FDA has standards for arsenic in water of 10 micrograms per liter, the FDA has no standards for arsenic in food. In fact, little is known about arsenic levels in foods because the FDA analyzes arsenic only on a case-by-case basis. Long-term studies that track health effects from extended exposure of arsenic in rice are recent, and epidemiological studies of lower-level arsenic intake from rice are needed.(2)
According to Consumer Reports, the EPA assumes there is actually no “safe” level of exposure to inorganic arsenic.(2) No federal limit exists for arsenic in most foods, and there is a need for a standard of arsenic in food. I personally believe that part of setting standards for arsenic in foods involves an understanding of the levels of arsenic found in all plant-based foods that we consume. Up to this point, arsenic levels have only been studied in rice, rice products, and apple juice.
Exposure to lower levels of arsenic can cause nausea, vomiting, abnormal heart rhythm, decreased production of red and white blood cells, impaired nerve function, damage to blood vessels, skin warts and corns, and red or swelling skin. Repeated exposure to arsenic can damage the liver and kidneys, cause stomach problems, and cause a darkening of the skin. Breathing high levels of arsenic can cause a sore throat or irritated lungs.(6) Emerging evidence suggests that arsenic may cause problems with brain development in children.(2) More evidence suggests that moderate levels of exposure may cause cardiovascular disease and chronic exposure may also effect the lungs, leading to breathing problems.(2) Chronic exposure to arsenic has very few symptoms, however, long-term exposure to arsenic from water is known to cause skin discoloration that looks like freckles or small moles on the hands, feet, or trunk.(2)
Here’s what you can do to limit your exposure to arsenic in rice:
Arsenic concentrates in the outer layers and the germ of the rice grain. Once the inedible husk is removed, leaving brown rice, the milling and polishing processes remove the outer layers of the brown rice to produce white rice. As a result, more arsenic remains in brown rice than in white rice.(1,2)
Just last week on September 6, 2013, the FDA released the analytical results of 1,300 samples of rice and rice products (1,100 new samples and 200 samples tested in 2012) as part of a major effort to understand and manage possible arsenic-related risks associated with the consumption of these foods.(4) According to the FDA report on Arsenic in Rice and Rice Products:
“The levels FDA found in its testing are too low to cause immediate or short-term adverse health effects. FDA’s work going forward will center on long-term risk and ways to manage it with a focus on long-term exposure.”(4)
In other words, they’re saying that it’s okay to eat rice and rice products at this point, which can change in the future once they've collected more data. However, they are recommending that alternatives to rice cereal be considered for an infant’s first solid food.(5)
There are two main forms of arsenic: inorganic and organic, and there are several species of each. Inorganic arsenic is of the most concern because it’s toxic; organic arsenic is less toxic.(1,2,3) However, the extent of toxicity of organic arsenic is not fully understood. Scientists at the FDA and in academic laboratories are developing new methods and improving old ones for identifying and quantifying arsenic in its various forms.(3) In the meantime, arsenic levels are reported as total arsenic (in parts per billion, ppb) and inorganic arsenic (ppb and in micrograms per serving; a serving of rice is 45 grams dry, about 1 cup of cooked rice). The FDA found varying levels of inorganic arsenic levels in rice ranging from 2.6 – 7.2 micrograms per serving, with instant rice (the most processed) being the lowest and brown rice being the highest.(4) These results are consistent with the 2012 Consumer Reports study.(2) While I didn’t find it indicated in the data that was just released last week, both the original FDA study of 200 samples and the Consumer Reports study of 223 samples showed that rice from the southeastern U.S. (rice and rice products) have higher levels of arsenic than rice from California.
Although the FDA has standards for arsenic in water of 10 micrograms per liter, the FDA has no standards for arsenic in food. In fact, little is known about arsenic levels in foods because the FDA analyzes arsenic only on a case-by-case basis. Long-term studies that track health effects from extended exposure of arsenic in rice are recent, and epidemiological studies of lower-level arsenic intake from rice are needed.(2)
According to Consumer Reports, the EPA assumes there is actually no “safe” level of exposure to inorganic arsenic.(2) No federal limit exists for arsenic in most foods, and there is a need for a standard of arsenic in food. I personally believe that part of setting standards for arsenic in foods involves an understanding of the levels of arsenic found in all plant-based foods that we consume. Up to this point, arsenic levels have only been studied in rice, rice products, and apple juice.
Exposure to lower levels of arsenic can cause nausea, vomiting, abnormal heart rhythm, decreased production of red and white blood cells, impaired nerve function, damage to blood vessels, skin warts and corns, and red or swelling skin. Repeated exposure to arsenic can damage the liver and kidneys, cause stomach problems, and cause a darkening of the skin. Breathing high levels of arsenic can cause a sore throat or irritated lungs.(6) Emerging evidence suggests that arsenic may cause problems with brain development in children.(2) More evidence suggests that moderate levels of exposure may cause cardiovascular disease and chronic exposure may also effect the lungs, leading to breathing problems.(2) Chronic exposure to arsenic has very few symptoms, however, long-term exposure to arsenic from water is known to cause skin discoloration that looks like freckles or small moles on the hands, feet, or trunk.(2)
Here’s what you can do to limit your exposure to arsenic in rice:
- Purchase rice that was grown in regions with lower levels of arsenic in the top soils such as California, India, and Thailand.
- Rinse your rice well before cooking and use the traditional method of cooking rice in Asia, that is, use a 6:1 water to rice ratio (instead of the typical 2:1 ratio). In other words, use 6 cups of water for every 1 cup of rice you cook. Using that much water means that like pasta, it won’t all get absorbed, and you will have to drain the excess water. Research has shown that this technique of rinsing and using excess water will remove roughly 30% of the rice’s inorganic arsenic.
- Use a variety of whole grains in addition to rice, including wheat, oats, quinoa, amaranth, and millet.
- Eat a well-balanced diet and avoid eating an excess of any one food.
- Instead of rice cereal, consider using an alternative for an infant’s first solid food.
Finally, granted I’m no expert, here’s my take on this topic: other cultures have consumed rice as their staple for as many as thousands of years and maintained good health. The healthiest cultures, especially those of Asia, have consumed mostly or entirely rice and vegetables. All plants have some level of arsenic, meaning that rice, as well as other fruits and vegetables including leafy greens, have always had arsenic, which we’ve consumed for all this time, and that hasn’t suddenly changed just because it’s now been measured. Until we know ranges of arsenic normally found in all plant-based foods, it’s difficult for us to know if the amount of arsenic found in rice is out of the range of what we normally consume in our diets. Rice stands out in terms of arsenic because as far as I can find, arsenic levels have only been measured in rice, rice products, and apple juice. We don’t know how much arsenic is in spinach, kale, broccoli, or potatoes, in meat due to the arsenic content in the grains that the animals ate, or in any other food. Measuring the levels of inorganic arsenic in our foods and improving our understanding of the toxicities of all arsenic species are key to resolving this issue. Plus, while there’s a difference of 4.6 micrograms (4.6 millionths of a gram) between the lowest and highest levels of inorganic arsenic measured in the most recent FDA study, we have no idea how significant that is. I believe that of bigger concern than the low microgram per serving levels of arsenic in rice are the levels of saturated fat, cholesterol, sugar, and salt that’s being consumed several times daily in the standard American diet (SAD). This appears to me to present much greater health risks that we routinely see on a much larger scale than those from consuming rice.
Resources:
Resources:
- http://www.webmd.com/diet/features/arsenic-food-faq
- http://www.consumerreports.org/cro/magazine/2012/11/arsenic-in-your-food/index.htm
- http://cen.acs.org/articles/91/i18/Eating-Arsenic.html
- http://www.fda.gov/Food/FoodborneIllnessContaminants/Metals/ucm319870.htm
- http://www.fda.gov/ForConsumers/ConsumerUpdates/ucm352569.htm
- http://toxtown.nlm.nih.gov/text_version/chemicals.php?id=3
- http://www.fda.gov/Food/FoodborneIllnessContaminants/Metals/ucm319916.htm
- http://www.fda.gov/food/newsevents/constituentupdates/ucm367510.htm
- http://healthland.time.com/2013/09/09/fda-says-arsenic-levels-in-rice-are-safe-for-now/