Some US fruit juices and plant-based milks contain heavy metals and toxic elements above US federal drinking water standards, according to a new study – but most products are within safe limits.

Researchers from Tulane University tested 60 commonly drunk beverages and found that five of them contained levels of a toxic metal above US federal drinking water standards.

The sample of 60 products included single and mixed fruit juices, plant-based milks, sodas, and teas.

Two mixed juices had levels of arsenic above the 10 microgram per litre standard. A cranberry juice, a mixed carrot and fruit juice, and an oat milk each had levels of cadmium exceeding the three parts per billion standard, the scientists found.

Lead was detected in more than 93% of the 60 sample although most contained very low levels, below 1 part per billion, according to the study, published in the Journal of Food Composition and Analysis.

Toxicity is unlikely with moderate consumption

“Mixed fruit juices and plant-based milk frequently contained elevated concentrations of most of the elements,” the scientists wrote in their conclusion. “While toxicity is unlikely unless individuals consume a large volume, moderating consumption of these beverages is required, especially to protect infants and young children. Regular monitoring of these chemicals in beverages is required for food safety and to provide sound nutritional advice.”

Tewodros Godebo, lead author and assistant professor of environmental health sciences at Tulane University School of Public Health and Tropical Medicine, said it was surprising there weren’t many studies evaluating the presence of toxic and essential elements in US soft drinks.

He added that the amount of toxic elements in the products were unlikely to pose a health risk to adults as they tended to be consumed in smaller quantities than water. However, there could be a concern for children, he said.

Avoid giving high quantities to children and young infants

“People should avoid giving infants and young children mixed-fruit juices or plant-based milks at high volume,” Godebo said. “Arsenic, lead, and cadmium are known carcinogens and well established to cause internal organ damage and cognitive harm in children, especially during early brain development."

Most of these elements found in beverages are believed to come from contaminated soil. The main sources of toxic metal contamination in soil and foods are linked to urbanisation and industrialisation, through the extensive use of fossil fuels, fertilisers, and metal-based pesticides during farming processes.

Tulane University student Hannah Stoner who participated in the study, said consumers need not fear but called for more research into the topic.

“In toxicity, it’s the dosage that often makes the difference so everything in moderation. But this creates awareness that there needs to be more study,” she said.

Chocolate and infant food also in the food safety spotlight

Products in other food and drink categories have been found to contain heavy metals.

In 2021, a report published by the US House of Representatives’ Subcommittee on Economic and Consumer Policy found that commercial baby foods are tainted with “significant levels” of toxic heavy metals, including arsenic, lead, cadmium, and mercury.

The findings prompted class action lawsuits against the food manufacturers and led to the US Food and Drug Administration (FDA) proposing limits on lead in processed baby food this year. Public health campaigners criticised the proposed levels, however, on the grounds they are voluntary and not low enough to sufficiently protect babies and infants.

Also in the US this year, non-profit organisation Consumer Reports tested 28 different dark chocolate bars in the US and detected “concerning levels” of cadmium and lead in all of them.