Rice and rice-based products are popular infant and toddler foods due to their low allergy risk, bland taste, and iron fortification, but rice has been found to contain two potential toxins, arsenic and micro plastics. (1) Only recently have the levels at which these two toxins appear in rice been shown to be potentially harmful to infants and toddlers. (1)
Arsenic
Arsenic is a naturally-occurring metalloid, found in both organic and inorganic forms in the air, water, and soil. (1) The organic form of arsenic is relatively harmless to humans, but the inorganic form is considered a carcinogen. (1) Rice accumulates more arsenic than other crops, a worrying fact, given the high rates at which infants and toddlers consume rice-based foods.
Chronic arsenic exposure early in life has been associated with poor growth, increased risk of respiratory infection, high blood pressure and compromised kidney function. (2)
Brown rice has been shown to contain more total arsenic, and inorganic arsenic, than white rice. Higher levels of inorganic arsenic have been found in organic rice compared to inorganic rice, possibly due to the inclusion of the whole grain in the organic product. (1) These findings are particularly concerning due to the association that many parents have of organic products being more nutritious and healthy than inorganic products. (1)
It wasn’t until 2016 that the European Union set limits of 0.1 mg kg-1 for inorganic arsenic levels in rice used for infant and toddler foods. (1) In Australia, the only existing guidelines were developed for adults and are still currently set at 1.0 mg kg-1 for total arsenic content in rice products. (1) These limits are clearly not suitable for infants and toddlers, many of whom consume large quantities of rice and rice-based products. (1)
One South Australian study looking at arsenic levels in supermarket rice and rice products found that 53% of these products contained more than the 0.1 mg kg-1 of arsenic recommended as a maximum for children in the European Union guidelines. (2) 22% of these products had double the maximum level. (2)
Recommendations to avoid overexposure to arsenic
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Limit servings of rice or rice-based products to one serving per day.
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Wash rice well before cooking and then cook thoroughly.
Microplastics in Rice
Another toxic material that has been found in rice are microplastics. (3) Research has uncovered that people are consuming around 3 - 4mg of plastic for every 100g of rice that they consume. (3) For pre-cooked or instant rice, this number is four times higher, with around 13mg of plastics being found per 100g or rice. Although there are a lot of unknowns about the exact dangers of accidentally consuming plastics in our foods, there is evidence that overexposure is a health risk. (3) Exposure to microplastics has been associated with increased inflammation and oxidative stress, leading to disruption of immune function and neurotoxicity. (4)
Another major concern is that microplastics may release their chemical constituents, for example Bisphenol A (BPA), once consumed. (4) Other chemicals commonly found in plastics are phthalates and some of the brominated flame retardants, and these have all been shown to be endocrine disruptors, damaging to health if inhaled or ingested. (5)
Research is too scarce for maximum limits to be set for microplastics in rice, but there are a few key tips to reduce overexposure:
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Wash rice well before cooking. This reduces the plastics by 20-40%. (3)
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Buy uncooked rice rather than the instant, pre-cooked options, which contain approximately 4 times the microplastics. (3)
Conclusion
Based on the current evidence, the key to avoiding overexposure to the arsenic and microplastics present in rice is to limit consumption of rice and rice-based products to one serving per day. Try replacing heavily processed rice snacks with whole foods and other grains, and, when serving rice, always wash well. Avoid buying the instant, pre-cooked packet rice if possible as this contains four times the microplastics compared to uncooked rice.
References
1. Gu Z, de Silva S, Reichman SM. Arsenic concentrations and dietary exposure in rice-based infant food in Australia. International journal of environmental research and public health. 2020 Jan;17(2):415.
2. Islam S, Rahman MM, Rahman MA, Naidu R. Inorganic arsenic in rice and rice-based diets: health risk assessment. Food Control. 2017 Dec 1;82:196-202.
3. Dessì C, Okoffo ED, O’Brien JW, Gallen M, Samanipour S, Kaserzon S, Rauert C, Wang X, Thomas KV. Plastics contamination of store-bought rice. Journal of Hazardous Materials. 2021 Aug 15;416:125778.
4. Prata JC, da Costa JP, Lopes I, Duarte AC, Rocha-Santos T. Environmental exposure to microplastics: An overview on possible human health effects. Science of the Total Environment. 2020 Feb 1;702:134455.
5. Campanale C, Massarelli C, Savino I, Locaputo V, Uricchio VF. A detailed review study on potential effects of microplastics and additives of concern on human health. International journal of environmental research and public health. 2020 Jan;17(4):1212.
Written By Clare Carrick
Clare Carrick is an accredited nutritionist whose special interests involve gut health, diet and its effect on mental health, early childhood nutrition, and the impact that diet during pregnancy can have on the health of the offspring. Clare studied a BHSc (nutrition & health promotion) at Deakin University, and completed an internship at the Food & Mood Centre, which specialises in nutritional psychiatry.
Although Clare enjoys getting deep in the science behind nutrition, she is also all about balance! Life is busy for her with two daughters under five and a growing nutrition business and, in all honesty, coffee is often her 1st thought when the alarm goes off in the morning! Whilst the abundance and diversity of the Mediterranean diet is definitely a favourite way of eating for Clare, perhaps her favourite part of it is the bit where she gets to sink into the couch at the end of a long day with a glass of red and know that the polyphenols are doing good things for her microbes.
