Whether you’re enjoying sushi, feeding your baby rice cereal or indulging in a rice pudding, it’s easy to see why rice is one of the most popular staples around the world.
But emerging research shows this beloved grain may be contaminated with arsenic — a toxic element linked to serious health risks, including brain developmental delays, cancer and heart disease.
That’s because rice has a unique ability to absorb arsenic, building up levels that can be 10 times higher than what’s found in other grains like wheat. The way rice is grown plays a big role: when it’s cultivated in flooded fields, the waterlogged soil makes arsenic more soluble and easier for the plant to take up, studies show.
But arsenic is a naturally occurring mineral found in soil and water, which means it can end up in a wide range of foods, including apples, Brussels sprouts and even drinking water in some areas.
So if it’s in a lot of foods, can it be all that bad for you?
“In rice and water, arsenic is in an inorganic form. Inorganic arsenic is a toxic chemical,” explained Molly Kile, an environmental epidemiologist at Oregon State University.
“But overall, the harm it can cause to human health depends on how much – and how long – a person has been exposed to it. So it is the amount and duration of exposure that inorganic arsenic a person experiences that determines how the magnitude of the risk it poses to health.”
Long-term exposure to inorganic arsenic, she said, has been linked to a higher risk of several serious health issues, including cancers such as skin, bladder and lung cancer, as well as Type 2 diabetes and preterm birth.
Health Canada and the International Agency for Research on Cancer classify arsenic as a cancer-causing substance. But its toxicity depends on the type: inorganic arsenic is the form most concerning for human health, and it’s more common in water and rice than in fruit.
“Inorganic arsenic is of greater concern to human health than organic forms of arsenic. Long-term exposure (over many years or decades) to very high levels of inorganic arsenic is associated with an increased risk of cancer and other adverse health effects,” Health Canada states on its website.
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But unlike the U.S., Canada has enforceable limits on how much inorganic arsenic can be present in rice sold to consumers. For example, white rice can contain no more than 0.2 parts per million (ppm) of inorganic arsenic, while brown rice can have up to 0.35 ppm.
One part per billion (ppb) is roughly like one drop of water in a swimming pool, according to the U.S. Environmental Protection Agency.
So, when we talk about 0.2 ppm, that’s the equivalent of about 200 drops of arsenic spread evenly throughout that same pool. For 0.35 ppm, you can picture around 350 drops of arsenic in the pool.
The U.S. Food and Drug Administration has regulated the levels of inorganic arsenic found in infant rice cereal, capping the level of arsenic allowable at 100 ppb. Health Canada has also regulated arsenic in infant rice cereal at the same level.
Although it seems like a small amount, given arsenic’s toxicity, even these small quantities are significant, especially for infants, Kile said.
“If a toddler and an adult both eat the same cup of rice containing 10 ppb of arsenic, the toddler would receive three times more arsenic per kilogram of body weight than the adult. That’s one reason why young children are more vulnerable to arsenic — they eat and drink more relative to their size, leading to higher exposures from the same food or water,” she said.
A new report published by Healthy Babies Bright Futures (HBBF), an American-based non-profit organization, found that rice sold in the U.S. contains high levels of arsenic.
In its recent report, HBBF tested 145 rice samples from various retailers across the U.S., including both domestic and imported types. The findings revealed that arsenic was present in 100 per cent of the samples, with more than one-quarter exceeding the federal limit set for infant rice cereal.
Brown rice grown in the southeast U.S. or labelled as “Grown in the USA” contained the highest average levels of heavy metals, the report said.
The reason brown rice has so much arsenic, Kile said, is that when it’s present in the soil and water, it builds up in the outer layers of the rice grain (the layers that brown rice keeps intact).
“This outer layer is removed during processing to make white rice. Brown rice retains these outer layers. So brown rice has more nutrients and fibre, which are good for you, but it will also have more inorganic arsenic than white rice. So it is a trade-off,” she said.
The report also found that alternative grains, such as quinoa, couscous and barley, have significantly lower total heavy metal contamination than rice. Precooked rice is convenient, but comes with potential risks from an unusually toxic form of arsenic, it added.
“We found four toxic heavy metals in rice — arsenic, cadmium, lead, and mercury. While each contaminant has different health effects, they can contribute to serious risks like cancer, developmental harm including IQ loss, and accumulation in the body over time. Arsenic was found at the highest levels, with cadmium next,” the report said.
Adding to these concerns, a May study in The Lancet Planetary Health warned that rising carbon dioxide levels and temperatures due to climate change are increasing arsenic levels in rice, potentially raising chronic health risks, especially in regions heavily reliant on rice.
A February study in Risk Analysis also found that Americans who regularly eat brown rice have higher arsenic exposure, with young children being particularly vulnerable because they consume more food relative to their body weight.
Even though arsenic levels in foods sold in Canada are generally low, Health Canada said there are ways to reduce your exposure through food.
You can start by eating a variety of healthy foods every day. That includes switching up your whole grains — don’t rely solely on rice. Try incorporating options like oats, barley, quinoa or whole wheat.
When you do cook rice, using extra water (at least six parts water to one part rice) and draining it afterward can help remove some of the arsenic, Health Canada said.
For babies and young children, offering a wide range of nutritious first foods is key. If you’re using iron-fortified infant cereal, choose versions made with different grains, not just rice. Health Canada also advises against using rice-based drinks as a milk substitute for children under two.
Kile echoed this advice.
“The good news is there are steps people can take that are proven to lower exposure: eat a varied diet, cook rice in extra water and drain it – like you would for pasta, and if you rely on well water, get it tested for arsenic,” she said.
“Arsenic can naturally occur in groundwater at levels that are much higher than in rice, and testing is the only way to know if it’s present in your well water.”
Rice can still be part of a healthy diet, she said, since it’s a nutritious staple, but be sure to switch it up and always rinse your rice before cooking.
“That way, you get the benefits of rice while lowering any potential risk that is posed by arsenic,” she said.
