Rice can be contaminated with arsenic. But there are ways to buy low-arsenic rice or use a specific cooking method to reduce arsenic exposure.
Arsenic in rice
Media reports often give the impression that rice is almost inedible because it is heavily contaminated with arsenic. However, rice is a staple food in many countries – and yet not all people there suffer from arsenic-related diseases. On the contrary. Although one z. For example, in Japan people eat rice several times a day, and the life expectancy of Japanese women is the highest in the world. It is therefore worth taking a closer look at the arsenic problem.
Organic and inorganic arsenic
Arsenic can be present in food in inorganic or organic form. Organic arsenic compounds are considered relatively harmless and can be found e.g. B. in fish, seafood, and algae. However, these three food groups contain not only organic arsenic but – just like rice – also inorganic arsenic (arsenite and arsenate) and this is exactly what is considered to be highly toxic and carcinogenic.
The following average levels of arsenic (inorganic arsenic) were measured in the foods mentioned:
- Fish: 45 µg/kg
- Seafood: 130 µg/kg
- Algae: 11,000 µg/kg
- Rice: 130 µg/kg
Cultivation in standing water promotes arsenic pollution
Since inorganic arsenic compounds are found practically everywhere in soil and water, plants absorb arsenic-contaminated water and accumulate the toxic substance in their leaves and seeds. Since rice naturally requires a lot of water – it is usually even cultivated in standing water – the rice plant also stores significantly more arsenic (up to 200 µg/kg and more) than other cereals. According to a study, the latter contains an average of only 7.7 µg/kg.
If the water used for irrigation were less contaminated with arsenic, the rice would be less contaminated. The arsenic contamination of rice, therefore, depends on the water quality.
Groundwater quality and pesticide use influence arsenic pollution
Groundwater is particularly contaminated with arsenic in regions where sewage enters the groundwater, leading to increased bacterial activity there, which in turn increasingly releases arsenic from the rock. The burning of fossil fuels or the use of arsenic-containing pesticides can also increase arsenic contamination in water. The greatest risk areas include India, Bangladesh, Thailand, and Vietnam.
Strain also depends on the rice variety
The arsenic content also depends on the rice variety. Basmati and jasmine rice contain significantly less arsenic than other varieties. This is i.a. This is due to the fact that these aromatic rice varieties are grown in the rainy season and therefore require less groundwater.
The cultivation of the rice varieties mentioned also requires fewer pesticides and fertilizers, which also reduces the number of pollutants entering the rice. At the same time, a study found that B. Jasmine rice not only contains little arsenic but at the same time also has more essential trace elements such as selenium and zinc – and thus has a double benefit for health.
Oko-Test results should be treated with caution
In recent years, the media has repeatedly emphasized that rice, especially whole-grain rice, is unhealthy due to the arsenic it contains. Wholemeal rice because pollutants and thus arsenic is stored in the surface layers of the rice grain in particular. But rice products (e.g. rice cakes) are also repeatedly discussed as being harmful to health, especially when they are children’s products, e.g. B. Rice-based baby food.
Oko-Test, for example, examined 21 varieties of rice in the autumn of 2017. Naturally, the polished rice varieties (white rice) were lower in arsenic because, as is well known, they lack the surface layer, while higher arsenic levels could be detected in brown rice.
Parboiled rice varieties were particularly heavily contaminated, because during the special hulling process not only the vital substances pressed from the outer layers into the interior of the grain but also the pollutants including arsenic.
Unfortunately, the corresponding test (as is usual with Oko-Test) does not give any concrete measured values, but only the assessment “increased” or “strongly increased”. An actual comparison is therefore not possible.
In this context, Rapunzel’s statement is interesting, so that apparently not all Oko-Test measured values have to be taken at face value (the Rapunzel rice had received a poor Oko-Test rating in the test presented):
For its assessment, Oko-Test uses an arbitrarily self-determined limit value of 0.1 mg/kg rice. The legal limit for inorganic arsenic is 0.2 mg/kg rice. 0.14 mg/kg were analyzed by Oko-Test in the Rapunzel “Natural long grain rice”. The laboratory analysis results available to us are 0.08 mg/kg.”
Spanish bomba rice hardly strained
The Arroz Bomba (Arroz is Spanish for rice) from the Pego region is one of the least arsenic-contaminated rice varieties. It is grown in the Marjal de Pego-Oliva Nature Reserve and is even recommended by EFSA for baby food. Even in the whole grain variants, the arsenic level was between 27.6 and a maximum of 40.9, and thus even below the maximum found in white bomba rice (24 to 44.9 µg/kg) (16).
However, we are not aware of any source for whole grain bomba rice. If you find one, please let us know! (Via the contact form).
Only those who eat a lot of rice every day are at risk
The International Agency for Research on Cancer (International Agency for Research on Cancer) has classified inorganic arsenic as “carcinogenic to humans”. With regard to rice, however, this effect would only come into play if nothing but the rice was eaten every day, as is the case in Asian countries on the part of the very poor population – e.g. B. in Bangladesh – is the case. However, these people also ingest high levels of arsenic in their drinking water. Arsenic levels of more than 200 µg per liter of water are not uncommon in some areas of Bangladesh.
Arsenic in rice and the risk of cancer
It is also interesting that bladder cancer in particular is one of the forms of cancer that are said to be caused by arsenic. But it is precisely this that occurs particularly frequently in Europe and the USA. Asia – i.e. where people eat an extraordinary amount of rice, which is said to be so dangerous – is the continent where bladder cancer occurs least frequently.
Other forms of cancer that are associated in particular with regular drinking of drinking water containing arsenic are lung and skin cancer, which can actually be observed more frequently in Asia than in other regions – whether the rice is responsible for it or rather the drinking water or both, is unknown however nobody.
Buy rice without arsenic
In summary, it would be ideal to switch to jasmine rice or basmati rice in the future. Since polished rice is less contaminated than whole-grain rice, white rice is often recommended. Apart from the fact that the advantages of the whole grain (higher vital substance and fiber content) can most likely compensate for possible arsenic contamination, we have seen above that the difference between white and whole grain basmati is not very big.
Ask the retailer about your favorite rice variety!
The best course of action, however, is to call or email the manufacturer of your favorite rice, rice cakes, or rice drink and ask them about their current analysis of arsenic levels. Precisely because the arsenic problem is so well known, every manufacturer of rice and rice products should be able to submit the relevant analyzes on a regular basis, which has long been the case with a number of organic suppliers, e.g. B. at Holle (baby food), Natumi (rice drink), Davert, Byodo, and others. So don’t hesitate to contact the distributor of your preferred rice variety.
Arsenic-free grain alternatives
If you want to eat less rice, then quinoa, millet, and buckwheat – all gluten-free like rice – are low-arsenic or arsenic-free alternatives. The oat or spelled grain is also only slightly contaminated with arsenic, if at all, and can be used cooked (let it soak overnight beforehand) as a grainy side dish.
Whilst side dishes such as spelled rice, einkorn rice, and pearl barley can also add variety, these are all ground grains, which means they are missing some of their outer layers, meaning they can no longer be considered 100% wholesome. The advantage is that these grain variants can be prepared more quickly and are ready to eat after about 20 to 25 minutes of cooking time without swelling.
Spelled rice is also sold under the designations Zart-Spinkel, Perl-Spinkel, Dinkelino, Bayerischer Dinkel, or Dinkel wie Reis. Of course, this is not rice, but a specially processed spelled that can be prepared and served like rice. The same goes for single-grain rice.
Prepare rice properly and thereby reduce the arsenic content
However, if you would rather eat rice but do not know whether your rice has a high or low arsenic content, you can reduce the arsenic content with a specific preparation method:
The arsenic content in rice can be reduced by washing it thoroughly with water before cooking. Therefore, it is often advised that one should rinse the rice with water until it runs clear. Since even more arsenic dissolves with hot water, the whole procedure should be done with the hottest possible water. However, since this method wastes a lot of water, we do not recommend it.
Before cooking, you can rinse the rice briefly under running water, then let it soak in hot water overnight and then drain the water.
Normally, rice is cooked with water in a ratio of 1:2 (2 parts water to 1 part rice), with the water evaporating or being absorbed by the rice at the end of the cooking time. But then the arsenic remains in the rice. Therefore, you should cook the rice in four to six times the amount of water and then pour the cooked rice over a sieve. The cooking water containing arsenic is therefore thrown away. In this way, the arsenic content can be reduced by about 75%.
The arsenic content can be reduced by 85% if the rice is prepared with a kind of percolator, a device known for preparing coffee, as researchers were able to show in a study in 2015. In the percolator, the cooking water is repeatedly pressed through the rice, taking the toxic inorganic arsenic with it.
Symptoms of arsenic exposure
Acute arsenic poisoning will not result from just consuming a portion of rice or a glass of rice drink from time to time. However, anyone who consumes a lot of rice and rice products without paying attention to the arsenic contamination and who, with a lot of bad luck, always eats heavily contaminated varieties could still suffer chronic arsenic poisoning in the course of his life.
Such could manifest itself with anemia, hair loss, liver dysfunction, muscle wasting, kidney failure, specific skin discoloration, and nerve inflammation, but also with cardiovascular problems and diabetes. Arsenic also inhibits the body’s own detoxification and is therefore doubly problematic.
Acute arsenic poisoning with rice consumption is not possible
The lethal dose of arsenic is 150 to 300 mg per kilogram of body weight. For example, if you weigh 70 kilograms, you would have to ingest 10.5 g to 21 g of arsenic to reach the life-threatening dose. Given these numbers, the levels of rice are rather low. Even highly contaminated rice varieties with e.g. B. 200 µg arsenic per kilogram would provide 12 µg arsenic per serving (60 g uncooked rice per person), i.e. 0.012 mg or 0.000012 g.
So in order to fatally poison yourself with rice contaminated with arsenic, you would have to eat 75,000 kilograms of rice at once (assuming 15 g of arsenic as the lethal dose), so that the risk of acute arsenic poisoning through rice consumption can be ruled out.
Arsenic exposure can be detected in blood or urine
Personal exposure to arsenic can be determined in the blood serum and also in the urine (arsenic is water-soluble). Naturopaths and environmental physicians usually detoxify arsenic using chelation therapy. If you are well supplied with vitamins B12, B2, B6, and folate (natural folic acid), arsenic cannot cause as much damage in the body as corresponding deficiencies – as we have already explained here (detoxification is more important than ever).