Updated: Jul 3, 2021
This question has been getting a lot of attention this year with the release of a concerning report from the US House Committee on Oversight and Reform. And unfortunately, the short answer is provided in the title of the report, "Baby Foods Are Tainted with Dangerous Levels of Arsenic, Lead, Cadmium, and Mercury" (U.S. House, 2021). All of these toxic heavy metals can lead to detrimental health and developmental outcomes, especially to infants who are particularly vulnerable to chemical toxicity.
The committee investigated seven of the leading baby food brands: Gerber; Nurture, Inc. (HappyBABY); Beech-Nut Nutrition Company; Hain Celestial Group, Inc. (Earth's Best Organic); Campbell Soup Company (Plum Organics); Walmart Inc. (Parent's Choice); Sprout Foods, Inc. (Sprout Organic Foods). The first four companies cooperated with the investigation, and it was discovered that their products contain toxin levels far exceeding guidelines set by the FDA and EPA. "The Food and Drug Administration has set the maximum allowable levels in bottled water at 10 ppb [parts per billion] inorganic arsenic, 5 ppb lead, and 5 ppb cadmium, and the Environmental Protection Agency has capped the allowable level of mercury in drinking water at 2 ppb. The test results of baby foods and their ingredients eclipse those levels: including results up to 91 times the arsenic level, up to 177 times the lead level, up to 69 times the cadmium level, and up to 5 times the mercury level" (U.S. House, 2021). The last three companies (Campbell, Walmart, and Sprout) failed to cooperate, leading the committee to speculate that "their lack of cooperation might obscure the presence of even higher levels of toxic heavy metals in their baby food products, compared to their competitors’ products". This report is disturbing and may prompt you to shake your fist at the evil corporations' manufacturing negligence. You wouldn't be wrong, but you should also be wary of a seemingly innocuous baby food ingredient that harbors toxic heavy metals: rice.
The baby food products with the highest arsenic levels contained rice flour (think puffs, cereal, and teethers/rusks). "Rice (Oryza sativa L.) has the ability to accumulate arsenic [from water and soil], amassing concentrations ten times higher than other cereals such as wheat" (Karagas, 2019). Arsenic toxicity is a rising health emergency in countries where there are high levels of environmental arsenic and rice is a dietary staple, such as Bangladesh and Vietnam (Rahman, 2011). In the US, white rice contains 131 ppb arsenic and 6.5 ppb cadmium. Brown rice is an even bigger offender, with arsenic and cadmium levels of 217 and 17.4 ppb, respectively (TatahMentan, 2020). Due to its higher nutrient content, however, brown rice flour is commonly included in "healthy" baby snacks. Further, "rice cereal can markedly increase arsenic exposure among US infants relative to breast milk and formula" (Carignan, 2016). The bottom line: steer clear of rice products even if they are targeted for babies. Beyond rice, there were a few other stand-out ingredients in the report: spices such as cinnamon, cumin, turmeric, and oregano contained high levels of lead; Amylase and BAN 800 (liquifying enzymes) contained high arsenic and lead (U.S. House, 2021).
Unfortunately, there are currently no federal regulations in place to require testing for or labeling of toxic heavy metals in baby foods. Because it's difficult/impossible to know which products contain dangerous toxins, the best practice to reduce exposure is to vary baby's diet (Korioth, 2021). For example, serving baby rice every once in a while is unlikely to cause problems, but eating brown rice day after day could potentially lead to an unhealthy accumulation of heavy metals. Mix up baby's diet (and your own) with a variety of fruits, vegetables, grains, and proteins to lower heavy metal intake with the added bonus of increasing nutritional diversity.
U.S. House. Committee on Oversight and Reform. Subcommittee on Economic and Consumer Policy. Baby Foods Are Tainted with Dangerous Levels of Arsenic, Lead, Cadmium, and Mercury. 2021. Available from: https://oversight.house.gov/; Accessed 6/29/21.
Karagas MR, Punshon T, Davis M, Bulka CM, Slaughter F, Karalis D, Argos M, Ahsan H. Rice Intake and Emerging Concerns on Arsenic in Rice: a Review of the Human Evidence and Methodologic Challenges. Curr Environ Health Rep. 2019 Dec;6(4):361-372.
Rahman MA, Hasegawa H. High levels of inorganic arsenic in rice in areas where arsenic-contaminated water is used for irrigation and cooking. Sci Total Environ. 2011 Oct 15;409(22):4645-55.
TatahMentan M, Nyachoti S, Scott L, et al. Toxic and Essential Elements in Rice and Other Grains from the United States and Other Countries. Int J Environ Res Public Health. 2020;17(21):8128. Published 2020 Nov 3.
Carignan CC, Punshon T, Karagas MR, Cottingham KL. Potential Exposure to Arsenic from Infant Rice Cereal. Ann Glob Health. 2016 Jan-Feb;82(1):221-4.
Korioth, T. (2021, May 1). Metal found in some baby foods, but varied diet can lower risk. American Academy of Pediatrics. https://www.aappublications.org/news/2021/05/01/parentplus-babyfoodmetal050121.