Aflatoxin contamination of commercially available areca nut products in Sri Lanka: a research note
This study reveals that sweetened areca nut (pani-puwak) sold in Sri Lanka's Kandy district is significantly contaminated with aflatoxins at levels exceeding European Union limits, thereby adding a critical carcinogenic risk to a product already linked to oral cancer.
Original paper licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). This is an AI-generated explanation of the paper below. It is not written or endorsed by the authors. For technical accuracy, refer to the original paper. Read full disclaimer
In many parts of South and Southeast Asia, a common habit involves chewing a small, hard seed known as the areca nut, often wrapped in a leaf with spices. For centuries, people have enjoyed this practice, but modern science has identified the nut itself as a direct cause of serious mouth diseases and cancer. The danger does not stop there. The same warm, humid climates that encourage the growth of this nut also foster invisible fungi that produce powerful toxins called aflatoxins. These toxins are among the most dangerous substances known to science; they can damage the genetic code inside human cells, leading to liver cancer and other severe illnesses. While scientists have long known that grains and spices can become contaminated with these toxins, the safety of the specific areca nut products sold in local shops has remained a mystery.
A team of researchers in Sri Lanka set out to solve this mystery by examining the four main types of areca nut products available to consumers. They looked at fresh nuts, sun-dried nuts, fermented nuts, and a popular sweetened version where the nut pieces are soaked in sugar syrup and sold in small packets. The scientists took samples from three different markets in the Kandy district and brought them to a certified laboratory. There, they used a highly sensitive method to hunt for traces of the four major types of aflatoxins, measuring how much of each toxin was present in every product. The process involved grinding the nuts, washing them with special liquids to pull out any hidden toxins, and then running the liquid through a machine that could detect even the tiniest amounts of contamination.
The results revealed a stark difference between the products. The fresh nuts, the sun-dried nuts, and the fermented nuts came back completely clean, showing no signs of these dangerous toxins at all. However, the sweetened product, known locally as pani-puwak, told a different story. This specific product was found to be contaminated with significant levels of aflatoxins. The total amount of toxins measured was 28.50 micrograms per kilogram. The most dangerous type of toxin, known as aflatoxin B1, made up the vast majority of this amount, reaching 23.47 micrograms per kilogram. To put this in perspective, the safety limits set by the European Union for tree nuts are set at 4 micrograms per kilogram for total toxins and 2 micrograms per kilogram for the most toxic type. The levels found in the sweetened areca nut were roughly seven times higher than the limit for total toxins and twelve times higher than the limit for the most toxic type.
The researchers believe they understand why this specific product is at risk. The process of making pani-puwak involves soaking the hard nut in a sugary syrup, which adds moisture and provides a food source for fungi. When these moist, sugar-coated packets are stored in the warm, humid conditions common in Sri Lanka, they create the perfect environment for the fungi that produce aflatoxins to grow. In contrast, the sun-dried and fermented versions of the nut have lower moisture levels or different chemical properties that keep the fungi from thriving, which explains why those products remained safe. The study also noted that while the contaminated sweetened product was technically within the very broad national limit for all foods in Sri Lanka, that limit is outdated and far less strict than international standards used for similar foods.
This discovery adds a new layer of risk to a product that is already known to cause oral cancer. The sweetened nut is often perceived as a milder or safer option, particularly by younger people, and is kept in the mouth for long periods, allowing the toxins to be absorbed repeatedly. The authors of the study emphasize that this is the first time such contamination has been systematically found in these retail products in Sri Lanka. They caution that because they only tested one batch of each product from a single district, the problem could be wider than this single snapshot suggests. They recommend that food safety officials begin monitoring these sweetened products closely, that manufacturers improve how they dry and store the nuts to prevent fungal growth, and that consumers become aware that this popular treat carries a hidden, serious health risk.
Drowning in papers in your field?
Get daily digests of the most novel papers matching your research keywords — with technical summaries, in your language.