A recent study has raised concerns after detecting dangerously high levels of lead in turmeric samples from India, Pakistan, Nepal and Sri Lanka, with some samples surpassing 1,000 micrograms per gram. The highest contamination was found in polished turmeric roots (polishing is believed to improve their appearance). This leads to a crucial question: should you be concerned about the turmeric in your food?

Are we right to worry?

Turmeric, often referred to as the "golden spice," is a staple in Indian cooking and is well-known for its medicinal properties. The active compound curcumin in turmeric is praised for its potent anti-inflammatory and antioxidant effects, which contribute to overall health. However, lead contamination in turmeric could undermine these health benefits and pose significant risks.

Lead - what is it?

Lead is a toxic heavy metal that occurs naturally in the earth's crust but can be harmful to human health when ingested over time. It is particularly dangerous because it can accumulate in the body, mimicking calcium and being stored in bones, where it can gradually interfere with vital organs and bodily functions. Lead exposure can come from various sources, including contaminated air, water, soil, and products like paints and fossil fuels.

In light of the concerning levels of lead contamination found in turmeric, it's important to evaluate the potential risks and explore safer sourcing alternatives to minimise exposure to this harmful heavy metal in everyday spices.

Study findings

A recent study published in Science of the Total Environment has revealed concerning levels of lead in turmeric from India, Pakistan, Nepal, and Sri Lanka. Some samples were found to contain over 1,000 micrograms of lead per gram—vastly surpassing the 10 μg/g limit set by India's Food Safety and Standards Authority (FSSAI). Around 14% of the samples tested showed lead levels exceeding 2 μg/g, raising alarms about the potential for widespread lead poisoning, particularly among children.

The study, conducted from December 2020 to March 2021, analysed samples from 23 cities across India, Pakistan, Nepal, and Sri Lanka. The highest levels of lead were detected in Patna (2,274 μg/g) and Guwahati (127 μg/g). Polished turmeric roots, which are often treated for better appearance, had the highest contamination, followed by loose turmeric powders. Notably, packaged and branded turmeric products tended to have lower lead levels, indicating that loose, unregulated turmeric is more vulnerable to contamination.

The main source of contamination seems to be lead chromate, a yellow pigment used in industrial products such as paints and plastics. The practice of adding lead chromate to

turmeric to intensify its colour has been linked to cases of lead poisoning, including ongoing incidents in Bangladesh since the 1980s.

Although the FSSAI has regulations banning the use of any foreign colouring agents, including lead chromate, the study emphasises the need for further investigation into the turmeric supply chain to determine how and why this harmful substance continues to contaminate the production process.

Human health impact of lead contamination

Lead exposure from contaminated turmeric presents serious health risks, especially for children. Even low levels of lead can impact nearly every organ and system in the body, with young children being particularly susceptible. In children, lead exposure has been linked to lower IQ, behavioural issues, developmental delays, and cognitive impairments, even at blood lead levels as low as 3.5 μg/dL. Worldwide, it is estimated that more than 800 million children have blood lead levels exceeding safe limits, underscoring the global threat of lead exposure.

The World Health Organization (WHO) estimates that lead exposure contributes to around 600,000 new cases of intellectual impairment in children each year, resulting in approximately 143,000 deaths—about 0.6% of the global disease burden. There is no safe level of lead exposure, particularly for children.

Is "Toxic Turmeric" a risk?

Turmeric is a staple in many South Asian households, and the Food Safety and Standards Advisory of India (FSSAI) has issued advisories to help consumers identify lead chromate, a common contaminant in turmeric.

Researchers caution that the high levels of lead found in some turmeric samples could have a serious impact on cognitive development, especially for children in regions like Bihar, where exposure could lead to a potential 7-point IQ reduction compared to unexposed children.

Lead exposure also poses risks to adults, contributing to cognitive decline, cardiovascular problems, kidney damage, and an increased risk of premature death.

What steps should consumers take?

To minimise the risk of lead exposure, consumers should buy turmeric from trusted sources that test for contaminants. While not all turmeric is harmful, these findings highlight the need for caution when selecting the spice you use regularly.

Lead in other foods: a widespread concern

Turmeric isn't the only food found to be contaminated with heavy metals. A study published in Frontiers in Nutrition in July 2024 revealed that certain chocolates sold in the US and Europe contain dangerously high levels of heavy metals, including cadmium and lead, exceeding the limits set by California’s Proposition 65.

Cocoa plants, which absorb cadmium from the soil, are a primary source of contamination in chocolate. Dark chocolate, with its higher cocoa content, tends to have more heavy metals than milk chocolate. Surprisingly, organic chocolates were found to have even higher levels of heavy metals than conventional ones, likely due to variations in soil composition and processing methods.

In conclusion, although turmeric offers many health benefits, consumers should be cautious of potential contamination and take care to ensure the quality of the products they buy.