Concerns about alleged 'harmful' arsenic levels in baby rice cakes

"Almost half of baby rice food products contain illegal levels of inorganic arsenic despite new regulations set by the EU, according to researchers," ITV News reports.

While this may sound shocking, arsenic is a common chemical compound naturally present in the environment.

It's found at very low levels in tap water in this country, but is present in foods that come from places where water contamination is higher.

At low levels, it causes no problems. The concern is whether levels could be high enough to cause health problems and, in the case of babies, developmental issues.

This study included 11 babies from Belfast who had their urinary arsenic levels measured pre- and post-weaning. Arsenic levels were higher post-weaning than pre-weaning, when most babies were eating some baby rice products.

Researchers also sampled baby rice products bought in February 2016, and found arsenic levels exceeded the maximum limit.

However, it was only in January 2016 that the European Commission introduced regulations on the amount of arsenic that should be present in rice.

As a spokesperson for the British Specialist Nutrition Association Limited, the trade group that represents rice cake makers, pointed out: "Research … was carried out using products bought in February 2016. This was one month after the application of the legislative requirements. It is likely that all samples were manufactured before the legislation came into force."

This research involved a very small sample from just one region. And there was no comparison group from elsewhere in the UK.

This means we can't conclude with any certainty that the measured arsenic levels can be directly attributed to rice, or that these levels would have any adverse developmental effects. Further testing of rice products could be useful.

Where did the story come from?

The study was carried out by researchers from Queen's University and Royal Victoria Hospital in Belfast, and Dartmouth College in the US.

Funding was provided by a Marie Curie Intra-European Fellowship within the 7th European Community Framework Programme, and the Metabolic Research Unit at the Belfast Health and Social Care Trust.

The study was published in the peer-reviewed journal PLoS One on an open access basis, and is free to read online.

While some of the headlines could be seen as alarmist, the general tone of the UK's media coverage was generally fair and balanced.

The Guardian is of one of many sources that provided helpful quotes from independent experts, including a spokesperson from the Food Standards Agency, who said:

"We recommend that consumers eat a balanced, varied and healthy diet. Rice and rice products can be part of that, including for young children.

"However, we do advise that toddlers and young children – ages 1-4.5 – should not be given rice drinks as a substitute for breast milk, infant formula or cow's milk.

"This is because of their proportionally higher milk consumption and lower body weight compared to other consumers." 

What kind of research was this?

This small cohort study aimed to assess arsenic metabolites in the urine of babies before and after weaning.

The researchers also analysed the levels of arsenic in rice cakes and other baby foods used in infant weaning to look at the association.

The researchers explain how early-life exposure to inorganic arsenic is of concern because it could impact health and development.

Arsenic in this country is found at low levels in water, so most exposure comes through dietary sources.

Infants and young children may be at greater risk of arsenic exposure because of their higher food consumption per unit of body weight.

Rice and rice-based products have been reported to contain higher levels of arsenic relative to other foods, and are commonly used in weaning.

In January 2016, the European Commission set a maximum level of inorganic arsenic in rice of 0.1mg per kg. But there's limited information on the impact of this regulation.

This study aimed to look at levels in baby rice, rice cakes and rice cereals compared with this standard, and look at child's levels before and after weaning. 

What did the research involve?

This cohort was set up to look at nutrition during pregnancy and then the first few months after birth.

Researchers recruited mothers who were Caucasian non-smokers with a healthy nutritional status from a hospital in Belfast.

Most (70%) were said to be of high socioeconomic status. Their babies included 41 girls and 38 boys born in 2015.

Infants were grouped into their feeding mode before weaning: breastfed (20), formula fed (32) and mixed feeding (27). Pre-weaning urine samples were collected at an average age of 3.4 months.

A small subsample of 11 infants (born September/October 2015) had post-weaning samples taken at an average age of 7.7 months.

An interview with their mothers at that time confirmed that all but one were eating rice-based products as part of their diet.

The researchers measured the arsenic levels in 13 samples of baby rice, 29 of rice crackers/cakes, and 31 samples of rice cereal from nine different manufacturers obtained from 17 shops in the Belfast area in February 2016.

What were the basic results?

The researchers reported levels of two arsenic metabolites (substances created when the metabolism breaks down compounds like arsenic): monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA).

They found that before weaning, infants who were exclusively formula fed had higher urine levels of MMA, DMA and total arsenic than those who were exclusively or partially breastfed.

For example, compared with breastfed infants, formula fed babies had 6.7 times higher levels of MMA, and around double the level of DMA and total arsenic.

Post-weaning urine samples contained higher levels of these metabolites than pre-weaning samples. Urine concentrations were about 7.2 times higher for MMA, 9.1 for DMA, and 4.8 times higher for total arsenic.

Around three-quarters of the baby rice and rice crackers (specifically marketed for babies) analysed exceeded the maximum set arsenic level of 0.1mg per kg, with an average concentration 0.117mg per kg (range 0.055 to 0.177). 

How did the researchers interpret the results?

The researchers concluded that, "Efforts should be made to provide low inorganic arsenic rice and rice-based products consumed by infants and young children that do not exceed the maximum level to protect this vulnerable subpopulation." 

Conclusion

Arsenic is found in the earth's crust and is naturally present in the environment. Certain countries – including India, China and Bangladesh – are known to have higher levels of arsenic in ground water than others.

Water supplies in the UK are low in arsenic, but we may be exposed to arsenic through foods – such as rice and other crops – that have been exposed to contaminated water.

This study shows that babies tend to have higher levels of arsenic metabolites in their urine when exposed to food – including formula milk and rice – and that rice contains higher than recommended levels.

These are important findings, but there are a few points to put this in context:

• This research used a small sample of infants (particularly the post-weaning sample of 11) and they're all from one region of Belfast with a very specific sociodemographic background (e.g. non-smoking white mothers of high occupational status). These levels may be representative of babies across the country, but we have none for comparison and don't know that for sure.
• Though nearly all of the 11 babies were given rice products, we can't conclude with certainty that this food was the direct cause of the higher levels.
• Continued exposure to high levels of inorganic arsenic is known to have toxic effects, possibly increasing the risk of cancer and affecting development. However, this study doesn't give evidence that the arsenic levels in urine observed here would be toxic to the child and could affect their future health. Again, there's no other group for comparison. Many healthy adults today could have had similar (or higher) levels of arsenic metabolites in their urine had they been tested as a baby.

These findings are, nevertheless, important. Europe set a limit on the amount of arsenic that should be present in rice products in January 2016.

Most products tested here exceeded this level, but they were bought in February 2016. It's possible this sampling may have been too close to when the legislation changed, and samples collected now may be different.