Media reports over the last decade have highlighted concerns about the arsenic content of rice and the potential health implications particularly for infants and young children.
This article looks at arsenic in the diet and the regulations in place that help ensure our intake is kept to safe levels.
What is Arsenic?
- Arsenic is a metal element that is naturally present in water, air and soil, and is absorbed by some food crops as they grow. It is not an additive or ingredient in these foods and cannot be completely eliminated from the food we eat or the water we drink.
- There are two general types of arsenic compounds. It is present in two general forms: inorganic and organic. These classifications are based on their carbon chemistry and are strictly not classified by the method of farming – as arsenic is in soil and water, both organically- and conventionally-grown crops will contain arsenic. It is inorganic arsenic that is widely considered detrimental to health.
- Currently, the Food Standards Agency (FSA) advises not to eat a type of seaweed called hijiki because it contains high levels of inorganic arsenic.
Arsenic and health
- Arsenic is a toxic substance. Studies have linked high chronic (prolonged or long-term) exposure with adverse health effects in multiple organ systems including the stomach, kidneys, liver, and in coronary heart disease and diabetes.
- The International Agency for Research on Cancer (IARC) classifies arsenic as a carcinogen based on the association between long-term exposure to arsenic with skin, lung and bladder cancers.
- Much of what we know about exposure to arsenic and its impact on health is based on people exposed to high levels over a long time, far in excess of what we are exposed to in the UK diet. High exposures are reported in areas of the world e.g. in parts of South America and Asia like Bangladesh and China where the levels of arsenic in the drinking water are very high, and markedly higher than those seen for rice consumption.
- From 2004, in the EU a stricter precautionary standard for a maximum total arsenic of 10 µg/l in drinking water came into effect.
- The main sources of our exposure to arsenic are food and water, although it should be noted that tobacco smoke contains arsenic.
- Arsenic is found in many foods including grains like rice, fruits and vegetables. It is also found in in seafood but this is the less toxic organic arsenic.
- Dietary exposure to inorganic arsenic for children under 3 years, including from rice-based foods, in terms of per kilogram bodyweight is estimated to be about on average 2- to 3-fold that of adults.
Why is rice is a particular concern?
- Arsenic is known to accumulate in rice at higher levels than in other crops, and is estimated to absorb up to 10 times the amount of other grains.
- The arsenic content in rice varies according to the type of rice, where its grown, how it has been processed and how it has been cooked.
- The maximum concentration of arsenic has been found in rice bran, so products made from this, for example rice milks, have a higher concentration.
Maximum limits of arsenic are regulated in Europe
- To help keep arsenic exposure low, the European Commission has set maximum limits for arsenic in rice and rice-based products, including rice cakes and rice destined for production of food for infants and young children. These came into force in January 2016, and are shown in the table below.
(mg/kg wet weight)
|Non-parboiled milled rice (polished or white rice)||0.20|
|Parboiled rice and husked rice||0.25|
|Rice waffles, rice wafers, rice crackers and rice cakes||0.30|
|Rice destined for the production of food for infants and young children||0.10|
Maximum levels of inorganic arsenic in foodstuffs as detailed in Commission regulation (EU) 2015/1006 amending Regulation (EC) No 1881/2006
What foods contribute the most arsenic to our diet?
- A 2014 European Food Safety Authority (EFSA) review of the main food contributors to dietary inorganic arsenic intake reported that with the exception of infants and toddlers, the main contributor was the food group ‘Grain-based processed products (non-rice-based)’.
- Other important contributors to the overall intake in all age classes were ‘Rice’, ‘Milk and dairy products’ and ‘Drinking water’.
- Whilst ‘Rice’ contains a comparatively high level of inorganic arsenic, the contribution to the dietary exposure from the other main food groups was mainly due to their relatively high consumption levels. In other words, we know rice has a higher level of inorganic arsenic, but our consumption patterns suggest that other grains provide more in the average European diet.
- In infants and toddlers, the main contributors were reported as ‘Milk and dairy products’ followed by ‘Drinking water’, ‘Grain-based processed products (non-rice-based)’ and ‘Food for infants and young children’. The contribution of infant food to arsenic intake may be underestimated since the EFSA database did not indicate the potential presence of rice in foods for infants.
Is the level of arsenic that children and adults consume likely to have an adverse health effect?
- EFSA in 2009 established a health-based reference value, a Benchmark Dose (Lower Limit) (BMDL01) for inorganic arsenic. The BMDL01 is the lower confidence limit for the dose that corresponds to a risk increase of 1 per cent (i.e. 1 case in 100 persons) for cancers of the lung, skin and bladder, as well as skin lesions.
- EFSA concluded that the overall range from 0.3 to 8 µg per kilo bodyweight per day should be used instead of a single reference point in any risk characterisation.
- An exposure assessment of inorganic arsenic intake across Europe (28 surveys from 17 European countries) was published by EFSA in 2014. This allowed an assessment of average intake of inorganic arsenic, as well as intakes in high consumer, per kilogram of bodyweight.
|Mean µg/kg b.w. per day||*95th percentile µg/ kg b.w. per day|
|Infant, Toddlers and children||0.20 to 1.37||0.36 to 2.09|
|Adults||0.09 to 0.38||
*Representing high consumers
Dietary exposure to inorganic arsenic in the European population
- This research indicates that our exposure rates are within the range proposed by EFSA. Therefore, in general our rice consumption does not pose a health risk.
- However, EFSA considered that because high consumers per kg/bodyweight (such as children under 3 years) can have intakes higher than the lowest level of the range (0.3), the possibility of a risk to some consumers could not be excluded.
- There is greater concern in young children because they will typically consume more per unit of bodyweight as well as having more selective eating patterns and limited dietary choices. For example, rice is used in many first foods.
- To mitigate the risks of exposure to arsenic, the Commission subsequent to their research introduced maximum legislative limits for inorganic arsenic in rice and rice-based products (see above) in tandem with a monitoring recommendation covering a wider range of foods to examine the need for further management actions.
- EU states have their own specific rules, with national safety bodies making recommendations on certain products.
- In the UK, for example, the FSA advises that toddlers and young children (up to 4.5 years) should not be given rice drinks as a substitute for breast milk, infant formula or cows’ milk. This is because of their proportionally higher milk consumption and lower bodyweight compared to other consumers. For all other consumers of rice drink there is no need to change their diet.
- The Swedish Food Standards Agency has advised that rice cakes should not be consumed by children under 6 years. However, neither the FSA, EFSA nor any other European countries have considered this currently a necessary approach.
- Safety experts do not consider that the arsenic exposure from eating rice and rice products a few times a week constitutes a health risk, and food-based dietary guidelines nationally and internationally include rice as part of the recommendations within the starchy carbohydrate food group.
- We do know that a healthy, balanced and varied diet is important to help ensure that a full range of essential nutrients are consumed. The emphasis on varied diets would counter a reliance on one grain, or excess intake of any one food, and include choosing a wide variety of grains. In the US, the Food and Drug Administration (FDA) emphasises this, and recommends to eat a well-balanced diet, varying grains and considering other grains as well as rice within an infant’s first foods
- High consumers of rice may wish to consider cooking methods which reduce arsenic concentration in rice.
- On behalf of the FSA, a study was undertaken to look at the effect of cooking methods on levels of arsenic in rice. Rinse washing was effective at removing around 10% of the inorganic arsenic from basmati rice, but was less effective for other rice types. High volume water:rice cooking (6:1) removed inorganic arsenic by 45% compared to uncooked (raw) rice.
Maximum levels for arsenic have initially only been set for rice and derived products, but plans are in place to monitor arsenic covering the period 2016-2018.
This purpose of this monitoring is to generate reliable occurrence data that can be used to correctly evaluate the need for setting additional maximum levels for other food commodities.
The commodities being monitored are cereal grains, cereal-based products (including bran and germ), fruit and vegetable juices, drinking water (including bottled water), coffee, dry tea leaves, beer, fish and seafood, vegetables, algae products (including hijiki), milk, dairy products, food intended for infants and young children, food for special medical purposes and food supplements.
The FSA continues to monitor arsenic intakes in infant foods.
EFSA (2009) Scientific opinion on arsenic in food. EFSA panel on contaminants in the food chain (CONTAM). European Food Safety Authority, Parma, Italy. EFSA Journal, 7(10): 1351.
EFSA (2014) Dietary exposure to inorganic arsenic in the European population. EFSA Journal 12(3):3597
FSA Arsenic in Rice https://www.food.gov.uk/science/arsenic-in-rice Last accessed February 2017
Hojsak I et al. (2015) ESPGHAN Committee on Nutrition Arsenic in rice: a cause for concern. J Pediatr Gastroenterol Nutr. :142–145.
Raab A et al. (2009) Levels of arsenic in rice: the effects of cooking. Foods Standards Agency Report C01049