By | June 19, 2017
arsenic levels in rice

Rice grains on the farm. Can you avoid or reduce your arsenic levels?

Is there arsenic in your rice or rice-based foods? Chances are, there is.

But not all rice contains unsafe levels of arsenic. This article will show you what rice foods are the worst, and how to select a safer rice.

In 2016, the Federal Drug Administration (FDA) tested infant cereals containing rice and found they had an average arsenic levels of 103 parts per billion (ppb) per serving.

Safe levels of arsenic in foods set by the European Union are 100 ppb. There are currently no safe levels set for arsenic in the United States, though the FDA did propose a 100 ppb “action level” for infant rice cereals on April 1, 2016.

The 2016 FDA study found that 53 percent of the infant cereals were above the 100 ppb levels set by the European Union. Non-rice cereals had little or no arsenic levels.

Many other rices high in arsenic

In 2013, the FDA conducted a larger study on arsenic in rice. Over 1,300 foods were sampled. This study found that some white rice products had up to 687 ppb levels of inorganic arsenic per serving.

Tests of long grain white rice from Texas topped the charts, with levels of different long grain white rices coming in at 684, 500, 402, 243 and many others coming in in the mid-100s ppb. Medium grain white rice levels from Texas tested as high as 572, 551, 522, 470 and several in the mid-300s ppb levels. Other USA-grown rices were also quite high, with some clocking in at 491 ppb, 345 and 262 ppb levels per serving.

California white rices tended to be significantly less than these. Medium grain white rices from California had a high of 100, with the rest in the 40s, 50s and 60s. There were others in the 70s and 80s, but most were in the 50s ppb levels per serving.

Among the brown rice tests there are were also high levels of inorganic arsenic. Texas brown rice was also quite high in some instances, with highs of 568, 489 and 476 ppb per serving. Again, California brown rice tended to be lower, but still had a high of 248 ppb with many others in the high-to-mid 100s. Louisiana brown rice tended to be in this range as well, with a high of 249 ppb. Arkansas brown rice was in the same range, with a high of 195 ppb.

Compared to these U.S. grown brown and white rice levels, Basmati rice from India was surprisingly lower. There was one batch that tested at 144 ppb, but many were under 100, with a greater proportion of 20s, 40s and 50s ppb compared to the U.S. grown brown rice.

This may be an element of the variety, because California Basmati rice levels also tended to be lower than brown rice levels. Many of the Basmati rices from California were in the 50s and 60s ppb. The highest ppb level for California Basmati rice was 105 ppb.

These results tell us that we’d probably end up with the lowest levels of inorganic arsenic by purchasing Basmati rice from either India or California.

Jasmine rice from Thailand also tested quite low for arsenic. One batch tested at 110 ppb, but others tested below 100, with several in the 70s and 80s.

Jasmine rice from California tested even better, at 34 ppb.

Boil-in-bag rices from the U.S. tended to be well under 100 ppb. Instant rices from the U.S. also tended to be significantly less than 100 ppb, though one came in at 134 ppb.

Anyway, Jasmine, Basmatic or brown rice is healthier than white or instant rice, as we have discussed. That’s because rice bran has significant health benefits.

Previous arsenic testing for rice

Numerous studies have been published over the past two decades documenting arsenic content in rice grown from around the world. A significant amount of the research came from Dr. Andrew Meharg, a professor of bio-geochemistry at the University of Aberdeen. Dr. Meharg has led or been part of the research teams in many of these studies, including some of the data for the FDA research.

These tests have mostly come in the form of micrograms per gram. This differs from the FDA data, which converted to ppb per serving – a simpler measure.

In 2007, Dr. Meharg led a study that measured arsenic levels among rice grown throughout the U.S. He and his team analyzed 107 samples of rice grown in Louisiana, Mississippi, Texas, Missouri, and Florida, and 27 samples of rice grown in California.

Meharg and his team found that the 107 southern US and central US rice samples averaged .30 micrograms per gram of arsenic (equivalent to 4.4 micrograms per serving), and the California rice samples averaged 0.17 micrograms/gram (ppm) (about 2.5 mcg per serving).

Dr. John Duxbury of Cornell University also studied U.S. rice, and discovered that the total arsenic content found in his samples were only 22% inorganic, while Dr. Meharg’s research showed that the inorganic arsenic content of the total arsenic content averaged nearly double these levels, at 42%.

Are arsenic levels lower in organic rice?

Arsenic in orgranic rice

Organic rice is lower in arsenic.

However,  Organic brown rice grown in California had the lowest levels of all 134 samples, with 0.10 micrograms/gram. This is equivalent to about 1.5 micrograms per serving – far less than the “worrisome” levels found in the FDA and Consumer Reports data. This indicates that organic rice will most likely be significantly lower in arsenic.

It should also be noted that these findings were on total arsenic content. Organic arsenic is a natural component of soils and is considered a trace mineral necessary for health. Inorganic arsenic is another creature altogether.

Meharg and his team found that the 107 southern US and central US rice samples averaged .30 micrograms/gram of arsenic, and the California rice samples averaged 0.17 micrograms/gram (ppm).

Organic brown rice grown in California had the lowest levels of all 134 samples, with 0.10 micrograms/gram. This indicates that organic rice is not necessarily higher in arsenic, and is most likely lower in arsenic.

The reason is found in the soil. Rice crops with more arsenic content are grown in fields that have been previously sprayed with arsenic-based chemical pesticides. Those arsenic residues will contaminate the soils for many years after the chemicals were sprayed (another reason to be buying organic foods). Cotton crops have historically been sprayed with arsenic-based pesticides to control boll weevils.

Accordingly, Louisiana rice – where a fair amount of rice is grown on land previously farmed in cotton – had the highest levels of arsenic in Dr. Meharg’s research. Louisiana rice had 0.66 micrograms/gram of arsenic. This means that the arsenic levels of the organic rice were 15% of the arsenic levels of the Louisiana conventional (non-organic) rice.

Dr. Meharg’s team calculated that using the arsenic content from the research, one would have to consume over 115 grams of rice to exceed the EPA’s standard of 10 micrograms/liter, equivalent to 10 parts per billion (ppb). The average American consumes only about 12 grams of rice per day. Asian Americans, however, average more than 115 grams of rice in a day.

Organic rice may also contain traces of inorganic arsenic due to the fact that inorganic arsenic is floating in our atmosphere from pollution, and some of our polluted waterways contain chemicals. Soils used for non-organic farming in the past may also contain arsenic. But conventional rice contains these and more, caused by a constant barrage of arsenic-loaded chemicals being sprayed on the crops.

What about rice milk?

Other studies by Dr. Meharg and his teams found that arsenic levels in rice milk often exceed the US as well as EU arsenic drinking water limits. They found that 80% of the rice milk samples they tested from supermarkets in 2008 exceeded 10 microgram/liter limit. Rice cakes and crackers also contained higher levels of arsenic according to another study.

Organic versus inorganic arsenic

Organic or inorganic arsenic has nothing to do with organic farming or organic foods. This is a chemical term relating to the type of arsenic molecule. Yet even in this respect, organic arsenic is better than inorganic in terms of toxicity.

The reason the molecule type is important is because organic unoxidized arsenic is a trace element found in nature, that is not necessarily harmful to the body in trace amounts. The body utilizes and metabolizes this form. It is the inorganic form – the oxidized versions called arsenic oxides or arsenic trioxide, typically used in industrial manufacturing of synthetic chemicals – that have been shown to be the most carcinogenic (although high quantities of organic arsenic can also be harmful and even carcinogenic).

In addition to cotton, fruit trees were sprayed with lead hydrogen arsenate for many decades. Now, conventional fruit trees are often sprayed with disodium methyl arsenate (DSMA) or monosodium methyl arsenates. These yield oxidized arsenic, but without the lead. Oxidized arsenic is also used in wood preservatives, antifungals and many other chemicals.

Regions with high arsenic levels

Research has illustrated that rice from Bangladesh has some of the highest arsenic levels in the world. This is not surprising, since Bangladesh has been faced with an arsenic catastrophe stemming from contaminated groundwater sources.

Dr. Duxbury holds that using less water to grow rice will dramatically reduce its arsenic content. California rice tends to be grown with less water, probably why it also tends to be lower in arsenic.

Dr. Meharg and his associates also studied arsenic levels in China’s rice. They found that most of the varieties contained less than .15 micrograms/gram, but rice grown in regions that were near or on previous mining sites had as much as .64 micrograms/gram.

Dr. Meharg’s research also discovered that some of the lowest arsenic levels among foreign rice are found in basmati rice from India and Pakistan and jasmine rice from Thailand.

Inorganic arsenic is carcinogenic

Organic arsenic in its unoxidized form is not necessarily harmful to the body in trace amounts. The body utilizes and metabolizes this form. The inorganic forms – oxidized versions such as arsenic oxides or arsenic trioxide, are produced with synthetic chemicals. These are the forms that have been found to be the most carcinogenic, although large amounts of organic arsenic are considered harmful and possibly even carcinogenic.

Dr. John Duxbury of Cornell University studied U.S. rice samples from different regions and found the total arsenic content averaged 22% inorganic, while Dr. Meharg’s findings showed that the percentage of inorganic arsenic to total arsenic content averaged 42%. This is explained by the fact that different soils have different levels of chemical contamination.

In other words, organic arsenic is readily present in natural soils, while inorganic arsenic is found in soils that have been sprayed with arsenic-based chemical pesticides, or watered with water containing chemicals high in arsenic. And since the plants will readily retain and store both forms, foods grown in soils that undergo chemical spraying – or have in the past – will contain higher levels of inorganic arsenic.

For example, cotton has been known to contain some of the highest levels of arsenic among U.S. crops. This is because cotton crops have historically been sprayed heavily with arsenic-based pesticides to control boll weevils.

Accordingly, Louisiana rice – where a fair amount of rice is grown in soils previously farmed in cotton – had the highest levels of arsenic in Dr. Meharg’s research. Louisiana rice had 0.66 micrograms/gram of arsenic. This means that the arsenic levels of the organic rice were 15% of the arsenic levels of the Louisiana conventional (non-organic) rice.

Other sources of arsenic contamination

In addition to cotton, fruit trees were sprayed with lead hydrogen arsenate for many decades. Now, conventional fruit trees are often sprayed with disodium methyl arsenate (DSMA) or monosodium methyl arsenates. These yield oxidized arsenic, but without the lead. Oxidized arsenic is also used in wood preservatives, antifungals and many other chemicals.

While there is no arsenic standard in food, there is an arsenic standard for drinking water, set by the U.S. Environmental Protection Agency. Using the average arsenic levels found in Dr. Meharg’s research, one would have to consume over 115 grams of rice to exceed the EPA’s standard of 10 micrograms/liter, equivalent to 10 parts per billion (ppb). The average American consumes only about 12 grams of rice per day. Asian Americans, however, average more than 115 grams of rice in a day.

A more recent Meharg study from Spain showed that most rice-based infant formulas – which used conventionally grown rice from around the world – also contained high arsenic content.

Other studies by Dr. Meharg found that arsenic levels in rice milk often exceed the U.S. as well as E.U. arsenic drinking water limits. Dr. Meharg and his team found that 80% of rice milk samples tested from supermarkets in 2008 exceeded the 10 microgram/liter limit. Rice cakes and crackers also contained higher levels of arsenic according to another study.

Dr. Meharg’s research also found that cooking rice in good water lowered inorganic arsenic content.

Research has illustrated that rice from Bangladesh has some of the highest arsenic levels in the world. This is not surprising, since Bangladesh has been faced with an arsenic catastrophe stemming from contaminated groundwater sources.

Dr. Duxbury’s research found that using less water to grow rice will dramatically reduce the arsenic content in the harvested rice.

Dr. Meharg and his associates also studied arsenic levels in China’s rice. They found that most of the varieties contained less than .15 micrograms/gram, but rice grown in regions that were near or on previous mining sites had as much as .64 micrograms/gram.

Dr. Meharg’s research also discovered that some of the lowest arsenic levels among foreign rice are found in basmati rice from India and Pakistan and jasmine rice from Thailand.

How to lower exposure to inorganic arsenic

The research clearly indicates that eating organic rice will dramatically lower one’s total arsenic exposure. Organic rice will lower one’s exposure to inorganic arsenic to an even greater degree because these fields are not sprayed with arsenic oxide-rich chemicals.

Rinsing the rice with water before cooking can lower polished rice or parboiled rice arsenic levels a little – 16 percent for polished rich and 9 percent for parboiled. However, rinsing rice before cooking does not reduce arsenic levels in brown rice.

The problem with rinsing rice before cooking is that it also reduces niacin levels by 85 percent, thiamine levels by 83 percent and folate levels by 87 percent for polished rice. Folate is reduced by 12 percent by rinsing brown rice before cooking. It’s not much, but folate is a necessary nutrient.

Cooking rice with excess water can significantly reduce arsenic levels. Cooking with between six-to-one and ten-to-one proportions of water can reduce arsenic in brown rice by 50 percent, polished rice by 43 percent and parboiled rice by 61 percent. However, these kind of water proportions will also decrease similar levels of iron, niacin, thiamin and folate from these rices.

A better strategy would be to choose organic Basmati rice and cook at normal proportions of water – between two-to-one and three-to-one.

Choosing organic rice grown in farming regions that have been farmed organically or lay fallow prior to being farmed will assure an even lower arsenic content in the rice. One of these growers is Lundberg Farms, a long-time California family farm that has been growing organic rice for decades (the author and website have no affiliation with Lundberg).

The Lundberg Farms’ organic rice is also grown with less water. As Dr. Duxbury’s studies showed, this decreases the uptake of arsenic in the rice.

For foreign rice, Basmati rice imported from India or jasmine rice imported from Thailand are better bets, especially if these rices are also certified organic.

An antioxidant-rich diet will also help reduce oxidized arsenic levels within the body.

Learn other strategies to cleanse toxins:

The Living Cleanse by Case Adams Naturopath

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REFERENCES:

U.S. Food and Drug Administration. “Questions & Answers: Arsenic in Rice and Rice Products.” April 1, 2016.

U.S. Food and Drug Administration. FDA proposes limit for inorganic arsenic in infant rice cereal. Press Realse April 1, 2016

Carbonell-Barrachina AA, Wu X, Ramírez-Gandolfo A, Norton GJ, Burló F, Deacon C, Meharg AA. Inorganic arsenic contents in rice-based infant foods from Spain, UK, China and USA. Environ Pollut. 2012 Apr;163:77-83.

Carey AM, Lombi E, Donner E, de Jonge MD, Punshon T, Jackson BP, Guerinot ML,  Price AH, Meharg AA. A review of recent developments in the speciation and location of arsenic and selenium in rice grain. Anal Bioanal Chem. 2011 Dec 8.

Abedin MJ, Cresser MS, Meharg AA, Feldmann J, Cotter-Howells J. Arsenic accumulation and metabolism in rice (Oryza sativa L.). Environ Sci Technol. 2002 Mar 1;36(5):962-8.

Meharg AA, Rahman MM. Arsenic contamination of Bangladesh paddy field soils: implications for rice contribution to arsenic consumption. Environ Sci Technol. 2003 Jan 15;37(2):229-34.

Williams PN, Price AH, Raab A, Hossain SA, Feldmann J, Meharg AA. Variation in arsenic speciation and concentration in paddy rice related to dietary exposure. Environ Sci Technol. 2005 Aug 1;39(15):5531

Williams PN, Islam MR, Adomako EE, Raab A, Hossain SA, Zhu YG, Feldmann J, Meharg AA. Increase in rice grain arsenic for regions of Bangladesh irrigating paddies with elevated arsenic in groundwaters. Environ Sci Technol. 2006 Aug 15;40(16):4903-8.

Williams PN, Raab A, Feldmann J, Meharg AA. Market basket survey shows elevated levels of As in South Central U.S. processed rice compared to California: consequences for human dietary exposure. Environ Sci Technol. 2007 Apr 1;41(7):2178-83.

Meharg AA, Deacon C, Campbell RC, Carey AM, Williams PN, Feldmann J, Raab A. Inorganic arsenic levels in rice milk exceed EU and US drinking water standards. J Environ Monit. 2008 Apr;10(4):428-31.

Zhu YG, Sun GX, Lei M, Teng M, Liu YX, Chen NC, Wang LH, Carey AM, Deacon C, Raab A, Meharg AA, Williams PN. High percentage inorganic arsenic content of mining impacted and nonimpacted Chinese rice. Environ Sci Technol. 2008 Jul 1;42(13):5008-13.

Sun GX, Williams PN, Zhu YG, Deacon C, Carey AM, Raab A, Feldmann J, Meharg AA. Survey of arsenic and its speciation in rice products such as breakfast cereals, rice crackers and Japanese rice condiments. Environ Int. 2009 Apr;35(3):473-5.

Raab A, Baskaran C, Feldmann J, Meharg AA. Cooking rice in a high water to rice ratio reduces inorganic arsenic content. J Environ Monit. 2009 Jan;11(1):41-4.

Williams PN, Price AH, Raab A, Hossain SA, Feldmann J, Meharg AA. Variation in arsenic speciation and concentration in paddy rice related to dietary exposure. Environ Sci Technol. 2005 Aug 1;39(15):5531

Williams PN, Islam MR, Adomako EE, Raab A, Hossain SA, Zhu YG, Feldmann J, Meharg AA. Increase in rice grain arsenic for regions of Bangladesh irrigating paddies with elevated arsenic in groundwaters. Environ Sci Technol. 2006 Aug 15;40(16):4903-8.

Williams PN, Raab A, Feldmann J, Meharg AA. Market basket survey shows elevated levels of As in South Central U.S. processed rice compared to California: consequences for human dietary exposure. Environ Sci Technol. 2007 Apr 1;41(7):2178-83.

Zhu YG, Sun GX, Lei M, Teng M, Liu YX, Chen NC, Wang LH, Carey AM, Deacon C, Raab A, Meharg AA, Williams PN. High percentage inorganic arsenic content of mining impacted and nonimpacted Chinese rice. Environ Sci Technol. 2008 Jul 1;42(13):5008-13.

Sun GX, Williams PN, Zhu YG, Deacon C, Carey AM, Raab A, Feldmann J, Meharg AA. Survey of arsenic and its speciation in rice products such as breakfast cereals, rice crackers and Japanese rice condiments. Environ Int. 2009 Apr;35(3):473-5.

Raab A, Baskaran C, Feldmann J, Meharg AA. Cooking rice in a high water to rice ratio reduces inorganic arsenic content. J Environ Monit. 2009 Jan;11(1):41-4. Epub 2008 Nov 20.