Gluten-free diet may increase risk of arsenic, mercury exposure

February 13, 2017 in Healthy Eating, Nutrition Topics in the News

Gluten-free diet may increase risk of arsenic, mercury exposure

Findings from a new study suggest that people who eat a gluten-free diet may be at risk for increased exposure to inorganic arsenic and mercury -- toxic metals that can lead to cardiovascular disease, cancer and neurological effects.

A gluten-free diet is a necessity for people with celiac disease, a lifelong inherited disorder that causes the body’s immune system to attack the small intestine when gluten – a protein found in wheat, rye and barley – is eaten. 

People with a condition called non-celiac gluten sensitivity also benefit by avoiding gluten.  These individuals test negative for celiac disease but react poorly to gluten experiencing symptoms such as bloating, abdominal pain, low energy and headache.

Gluten-free diets have also caught on with people who aren’t sensitive to the protein in the belief it’s a healthier way to eat. 

Rice-based products may be a concern

Gluten-free products often contain rice flour as a substitute for wheat. Rice is known to accumulate certain toxic metals, including arsenic and mercury from fertilizers, soil, or water, but little is known about the health effects of diets high in rice content.

Arsenic is found in low levels in many foods including grains, fruits and vegetables, fruit juices and meat since the chemical is absorbed through soil and water. However, rice accumulates arsenic far more readily than other plants because it’s grown in standing water.

Researchers from the University of Illinois in Chicago School of Public Health looked at data from the National Health and Nutrition Examination Survey searching for a link between gluten-free diet and biomarkers of toxic metals in blood and urine.

They found 73 participants who reported eating a gluten-free diet among the 7,471 who completed the survey, between 2009 and 2014. Participants ranged in age from 6 to 80 years old.

Gluten-free dieters had higher arsenic, mercury

People who reported eating gluten-free had higher concentrations of arsenic in their urine, and mercury in their blood, than those who did not. The arsenic levels were almost twice as high for people eating a gluten-free diet, and mercury levels were 70 percent higher.

Studies need to be conducted to determine if there are corresponding health consequences that could be related to higher levels of exposure to arsenic and mercury by eating a gluten-free diet that contains rice and rice flour products.

In Europe, there are regulations for food-based arsenic exposure but not in the United States or Canada.

Tips to reduce arsenic exposure from rice

Rice is a nutritious food that delivers carbohydrate, B vitamins and minerals. And, if you choose brown rice, which I recommend, you’ll get fibre and phytochemicals, too.

Rice shouldn’t be the only grain you eat, though.

Both Health Canada and the US FDA advise consuming a variety of grains to minimize exposure to inorganic arsenic from rice.  Other iron-fortified cereals for infants include oat, barley and multigrain.

Cooking rice in lots of water (6 parts water to one part rice) and draining off the excess water has been shown to reduce inorganic arsenic content by 40 to 60 per cent.

If you eat a gluten-free diet, include alternatives to cereals, crackers, breads and crackers made from rice/rice flour. A 2014 Consumer Reports analysis found that amaranth, buckwheat, millet and whole grain corn (polenta) – all gluten-free – have negligible levels of arsenic.

Quinoa (gluten-free) and gluten-containing bulgur, barley and farro have low levels.

Source: Epidemiology, February 3, 2017.

All research on this web site is the property of Leslie Beck Nutrition Consulting Inc. and is protected by copyright. Keep in mind that research on these matters continues daily and is subject to change. The information presented is not intended as a substitute for medical treatment. It is intended to provide ongoing support of your healthy lifestyle practices.