Gluten-free staple identified as toxic metal contributor: Study

Commercial gluten-free products primarily contain rice flour as a substitute for gluten-containing crops such as wheat, rye and barley. ©iStock/Tashka2000

Rice flour, a staple ingredient used in commercial gluten-free products, has been suggested to contain increased levels of toxic metals linked to heart and brain disorders.

Data collected from a survey found those following a gluten-free diet had urine arsenic levels almost twice as high as those following a conventional diet.

Mercury levels in the blood were found to be 70% higher in gluten-free individuals, according to the research team

The findings also speculate that rice may be the main contributing factor in the observations garnered from this study.

Commercial gluten-free products use rice flour as the primary substitute for wheat which, along with rye and barley, tend to aggravate an inflammatory gut reaction that characterises Coeliac disease.

“These results indicate there could be unintended consequences of eating a gluten-free diet,” said Dr Maria Argos, assistant professor of epidemiology at the University Of Illinois Chicago School of Public Health

“More research is needed before we can determine whether this diet poses a significant health risk.”

Further research needed

While the study is cross-sectional and relies on self-reported data, the results do suggest further studies are required to fully examine this toxic metal exposure as a result of following this diet.

Previous studies looking into low-level arsenic and mercury exposure from food sources have proved inconclusive but a link to neurological and other chronic conditions remain present.

In July 2014, UN food standards body the Codex Alimentarius Commission adopted new standards to protect consumer health worldwide.

This included setting out a maximum acceptable level of arsenic in rice of 0.2 milligrams per kilogram (mg/kg).

This was closely followed up in June 2015, where the European Commission proposed an arsenic level contained in non-parboiled milled rice (polished or white rice) to be no more than 0.2 mg/kg. 

This proposal was made mandatory in all EU member states from the 1 January 2016 onwards.

Dr Argos and her colleagues looked at data from the National Health and Nutrition Examination Survey.

A total of 73 subjects were identified as consuming a gluten-free diet among the 7,471 individuals who completed the survey.

The questionnaires were distributed and completed between 2009 and 2014 and subjects ranged in age from 6 to 80 years old.

Along with arsenic and mercury, higher concentrations of dimethylarsonic acid and urinary cadmium were found among those on a gluten-free diet.

‘Health effects from exposure unknown’

“To our knowledge, this is the first analysis to suggest that Americans on gluten-free diets may be exposed to higher levels of arsenic and mercury,” the study said

“With the increasing popularity of gluten-free diets, these findings may have important health implications since the health effects of low-level arsenic and mercury exposure from food sources are uncertain.”

According to the Food and Agriculture Organisation (FAO), arsenic is naturally present at high levels in the groundwater and soil in some countries.

The food chain can become contaminated when the toxic elements enter the water and soil that are utilised by the crops.

Rice is particularly vulnerable as it can absorb more arsenic than other crops. Rice is also a staple food for millions of people significantly increasingly arsenic exposure in a population.

Source: Epidemiology

Published online ahead of print: DOI: 10.1097/EDE.0000000000000640

“The Unintended Consequences of a Gluten-Free Diet.”

Authors: Maria Argos et al

Related News

Gluten-free pasta tends to be lower in fat, calories and sugars than standard pasta

How nutritious are gluten-free foods?

'Targeting new consumer groups, with different lifestyles as well as looking at geographies will be their best way forward in finding new growth opportunities,' said Fokke van den Berg from DSM

DSM promises simpler way to make gluten-free beer

A threshold of 20ppm is producing 'very safe' foods for coeliacs

European gluten-free thresholds are working to protect coeliacs, study finds

Gluten free furore highlights inaccurate reporting

Gluten free furore highlights inaccurate reporting

Gluten-free taste improvements spur market growth

Gluten-free taste improvements spur market growth

'The research around gluten-free products is very inconclusive,' says a food scientist

Gluten-free health benefits? For those without an intolerance there's no proof, claim experts

A 135% gluten-free industry growth from 2013 to 2015, reaching estimated sales of $11.6 bn (€10.4 bn) in 2015, was noted in the commentary piece. (© iStock.com)

Expert dispels common myths in following a gluten-free diet

Comments (2)

Adrian T - 17 Feb 2017 | 07:15

Were rice ingredients analyzed?

Is this a hypothetical link, or did the researchers provide any actual assay evidence of higher or out-of-specification content of heavy metals in the actual foods and ingredients that are incriminated by this report?

17-Feb-2017 at 19:15 GMT

Nancy - 15 Feb 2017 | 06:49

Question

Does it concern organic rice too, or only conventional rice??

15-Feb-2017 at 18:49 GMT

Submit a comment

Your comment has been saved

Post a comment

Please note that any information that you supply is protected by our Privacy and Cookie Policy. Access to all documents and request for further information are available to all users at no costs, In order to provide you with this free service, William Reed Business Media SAS does share your information with companies that have content on this site. When you access a document or request further information from this site, your information maybe shared with the owners of that document or information.