Arsenic, mercury, lead—the list of heavy metals that have been discovered in baby food and formula goes on. A 2017 study of 105 baby rice cereals from the advocacy group Healthy Babies Bright Futures found that the cereals contained an average of 85 parts per billion of arsenic, and many cereals exceeded the Food and Drug Administration's proposed limit of 100 parts per billion. Meanwhile, research published in the Journal of Agricultural and Food Chemistry found mercury in little ones’ rice cereals. Even apple juice has made headlines for arsenic and lead.
Scary stuff. But what do these studies mean? Should parents be clearing out their cupboards?
The unsettling truth is we just don’t have enough information. While almost all food contains trace amounts of metals, which occur naturally in the earth and can be transferred during processing, a small number of baby food samples have revealed worrying levels. For example, the Healthy Babies Bright Futures study found one cereal that registered at 235 parts per billion, more than two times the cutoff proposed by the US and European regulatory agencies. But many studies like this don’t test enough samples to be able to make conclusions about any specific product. “You would need way more samples,” says Ray Copes, chief of environmental and occupational health at Public Health Ontario. He points out that levels of arsenic, for example, can vary dramatically from one rice paddy (field of rice) to another in the same geographic region—so a rice cereal that tests low one time could test high another (and vice versa).
In some instances, though the presence of trace metals sounds alarming, the levels found are within limits set by regulatory agencies. For example, the study that found mercury in cereals concluded that most cereals wouldn't put infants over the upper limit for mercury consumption set by the US Environmental Protection Agency, while a handful of the 119 cereals tested would put them slightly above the recommended limit of 0.1 micrograms per kilograms of body weight per day.
It’s unclear whether exceeding the limits poses real health risks. We know these heavy metals are very dangerous in high amounts—arsenic is a carcinogen, and lead poisoning can occur when a baby eats lead paint chips, for example. But they may not be safe in low amounts either. Studies have found that chronic exposure to low levels of lead can have slight effects on IQ.
The good news is that kids' blood-lead levels are dropping, in large part because of the government’s ban on lead in gasoline in 1990. From 2009 to 2015, the mean blood-lead level in Canadian children ages three to five dropped from 0.93 to 0.67 µg/dL. “I think that’s something that today’s parents should find very comforting,” says Copes.
And as studies raise concerns about heavy metals in food, regulators are responding. Health Canada has proposed lowering the maximum limit of arsenic in apple juice and water, for example. That’s not to say we couldn’t do better. Health Canada still doesn’t have an upper limit for arsenic in baby cereals, although in April 2019 it announced it is launching a consultation process to set one. In 2016, the European Commission set an upper allowable limit of arsenic in rice (including rice cereals) at 100 parts per billion and the US Food and Drug Administration (FDA) has proposed doing the same.
So what are parents to do while all this research is emerging? Diversifying kids’ diets with various fortified grain cereals is a good place to start. And it's what the FDA recommends. For example, since rice is commonly contaminated with arsenic, Jennifer Lowry, section chief of toxicology and environmental health at Children’s Mercy Hospital in Kansas City, says parents should also feed their children other grains like oatmeal, buckwheat and quinoa. “Rice is great, but it shouldn’t be the only thing children eat.”