Consumers are being advised not to eat the traditional Japanese seaweed hijiki due to arsenic levels, but the company behind the tested product says levels did not exceed its own limits.
Hijiki is a dark-coloured shredded seaweed that has formed part of the traditional Japanese diet for centuries and features on the menu of Japanese restaurants as a starter or side dish. It is sold outside Japan in specialty supermarkets for home consumption and, although it does accumulate organic and inorganic arsenic, it is a source of fibre and minerals.
The UK’s Food Standards Agency (FSA) has reiterated advice first issued in 2004 that consumers should avoid it, but it has tempered that by saying that that anyone who has eaten hijiki occasionally should not panic. It is unlikely to have had an impact on their risk of developing cancer.
The advice stems from a notification from the European Commission about inorganic arsenic levels found in a product from UK company Clearspring, which was analysed by authorities in Switzerland where arsenic limits for foods are in place.
Awareness of arsenic levels in hijiki is not new. In 2004 the FSA conducted a survey of arsenic levels in different forms of seaweed in which hijiki was found to contain inorganic arsenic, the form that has been linked to human cancer risk, but other varieties like arame, kombu, nori and wakame did not.
Levels of inorganic arsenic were seen range from 30.9mg/kg down to 7.9mg.kg in prepared hijiki, and from 96.2mg/kg down to 68.8mg/kg as sold.
The batch concerned is not thought to have been contaminated or produced in inappropriate conditions. The product originated from a UK company called Clearspring, which specialises in organic and traditional foods.
“The total arsenic content found in the lot of Clearspring Hijiki that was the subject of the notification that triggered the re-issue of the advice was slightly above average and below our limit,” Clearspring product quality and development manager Maria Furugori told FoodNavigator.com.
"In line with the opinion issued by the Japanese Ministry of Health & Welfare in response to the original FSA warning, we remain confident that hijiki can be consumed safely in small quantities when prepared appropriately. Our packs advice a maximum weekly consumption of 5g for adults. Furthermore, the cooking preparation steps of soaking, draining, rinsing and cooking we indicate are known to significantly reduce the arsenic content.”
However there are no EU-wide levels for arsenic in foods. In September last year the European Food Safety Authority (EFSA) published a scientific opinion in which it recommended reducing dietary exposure to inorganic arsenic. It said it is inappropriate to identify a tolerable daily or weekly intake level for arsenic.
“Once these are available, we will ensure that our product complies with these,” said Furugori.
In the meantime, the company has food safety management systems in place and tests the arsenic level in every batch of hijiki it imports, she said, “to ensure it does not exceed the limit that we have calculated to be safe using reference values published by international food safety agencies”.