Aside from adding flavor and color to curries and other dishes, turmeric is also seen as something of a wonder spice that can be used to treat everything from inflammation to gastric disorders. However, alarming new research has revealed that many producers in Bangladesh regularly adulterate their turmeric with lead in order to intensify its bright yellow hue and enhance its market value.
Popular worldwide for both culinary and medicinal purposes, turmeric is mainly produced in Bangladesh, India, Myanmar, China, and Nigeria. Yet during a recent visit to the nine major turmeric-producing regions of Bangladesh, a team of researchers from Stanford University uncovered some shocking facts about the sought-after yellow root.
Describing their findings in the journal Environmental Research, the authors reveal how conversations with farmers and merchants first alerted them to the worrying practice. From their interviews, the team learned that floods in the 1980s had resulted in poor turmeric harvests, with soggy crops that were dull in color. To increase the market value of their yield, producers began treating it with lead chromate, a yellow pigment that enhanced the vibrancy of the root.
After learning that the practice remains popular to this day, the study authors then conducted a chemical analysis of 524 samples of turmeric, pigments, dust, and soil from across Bangladesh. In doing so, they discovered lead concentrations that exceeded the national limit by up to 500 times, with an average of 690 micrograms of lead in each gram of turmeric.
As anyone who followed the recent water crisis in Flint, Michigan, will know, lead is a neurotoxin that can cause severe health defects if it enters the food supply. Studies have shown that children who ingest lead tend to suffer from a reduction in cognitive capacity as their neurodevelopment becomes compromised.
Highlighting the need to completely eliminate lead from the food and water supply, study co-author Stephen Luby explained in a statement that “unlike other metals, there is no safe consumption limit for lead, it’s a neurotoxin in its totality.”
While the study does not investigate the presence of lead in turmeric outside of Bangladesh, the authors suggest that the strict health and safety guidelines of other countries are likely to deter producers from adding lead to any product that is destined for export. In spite of this, however, they point out that there is no telling how much adulterated turmeric may be circulating worldwide, and therefore call for more stringent testing on all turmeric at the point of import.