Reader Carol G. asks: “I read that rice products have low levels of arsenic. I am gluten-free for health reasons, so I consume rice regularly. Is there a maximum quantity that I should consume to limit my exposure to arsenic? Or am I concerned unnecessarily?”
Globe Life contributor Kat Sieniuc investigated:
The short answer is: yes, there are low levels of arsenic in most of the rice we eat. Not surprising to chemists and food safety experts, trace amounts of arsenic actually is present in many foods, and rice is especially prone to accumulating it. For consumers, this may come as a shock.
Arsenic is a naturally occurring element present in rock, soil, water and air that was once used in pesticides and, until 2009, by poultry farmers in medication targeting parasites in their birds. Today, arsenic shows up as largely a byproduct of heavy metal industry.
It exists in two chemical forms: a less toxic organic form that we can ingest with virtually no risk and a slightly more toxic inorganic form that reacts in our bodies and can do damage.
In 2012, Consumer Reports conducted a study that found measurable levels of arsenic in almost all of the 60 rice variables and rice products they tested. Further study showed that the inorganic arsenic levels found in rice varied across geographic locations and types of rice.
- White basmati rice from California, India, and Pakistan, and sushi rice from the U.S. had half of the inorganic-arsenic amount of most other types of rice.
- Rice from Arkansas, Louisiana, or Texas had the highest levels of inorganic arsenic.
- White rice from California had 38 per cent less inorganic arsenic than white rice from other parts of the country.
- Brown rice had 80 per cent more inorganic arsenic on average than white rice of the same type (this is because it accumulates in the grain’s outer layers, which are removed to make white rice).
- And rice that’s grown organically took up arsenic the same way as conventional rice.
But how dangerous is arsenic – and should we be limiting the amount of rice we eat?
“Essentially… you would need to eat 3 kg of rice a day to get noticeable toxic effects,” says Keith Warriner, a professor of food science at the University of Guelph. He says an international group of food safety experts called Codex has recommended a maximum level for arsenic in rice of .02 mg per kg – which means most of us don’t come close to eating toxic levels.
While Codex recommends adults limit their rice servings to four per week, and zero for children under five, Health Canada and the Canadian Food Inspection Agency say the trace amounts of arsenic found in food are not considered a safety concern for Canadians.
Warriner says that while the risk of arsenic exposure from eating rice is minimal, there are precautions you can take if you are really concerned:
- Eat white rice, which has a lower arsenic level than brown
- Soak rice overnight prior to cooking – this eliminates inorganic arsenic by 30 to 60 per cent
- Choose rice sourced from geographic regions known to have lower levels of arsenic in its soil like India, Pakistan or California