International Agency for Research on Cancer (IARC) - Summaries & Evaluations

Chinese-style salted fish (Group 1)
Other salted fish (Group 3)

For definition of Groups, see Preamble Evaluation.

VOL.: 56 (1993) (p. 41)

5. Summary of Data Reported and Evaluation

5.1 Exposure data

Salted fish is prepared by treating fish with dry salt or an aqueous salt solution and is often subsequently dried in the sun. It is produced and consumed primarily in Southeast Asia and northern Europe. Chinese-style salted fish is usually softened by partial decomposition before or during salting. High levels of N-nitrosodimethylamine have been reported in some samples of Chinese-style salted fish.

5.2 Human carcinogenicity data

The pattern of nasopharyngeal carcinoma incidence in China reflects the pattern of consumption of salted fish. Eight case-control studies consistently demonstrate that consumption of Chinese-style salted fish is strongly related to risk for nasopharyngeal carcinoma. The effect remained in studies that controlled for other risk factors. A significant dose-response relationship is seen between frequency of intake and risk for nasopharyngeal carcinoma, and the association is especially strong for intake of salted fish during childhood. Two further case-control studies, on oesophageal cancer and stomach cancer, found nonsignificant associations with consumption of Chinese-style salted fish.

The association between cancer and the consumption of other types of salted fish was examined in several studies. A study in Tunisia and one in Alaska suggested a relationship between intake of salted fish and nasopharyngeal carcinoma. Ecological studies in Japan showed a correlation between consumption of dried or salted fish and cancers of the stomach and oesophagus. One cohort study in the USA and three case-control studies in Hawaii, Japan and Italy showed positive associations between intake of dried or salted fish and risk for stomach cancer; a cohort study from Hawaii and two case-control studies from Japan found no association. In none of these studies was the effect of salt consumption evaluated independently.

Studies on cancers at other sites were not considered informative for the evaluation.

5.3 Animal carcinogenicity data

Chinese-style salted fish was tested in two studies in rats by administration in the diet or in the diet and drinking-water. A small number of carcinomas was oberved in the nasal, paranasal and oral cavities in each of the studies in rats, mostly in females.

5.4 Other relevant data

Extracts of Chinese-style salted fish are mutagenic to bacteria.

5.5 Evaluation

There is sufficient evidence in humans for the carcinogenicity of Chinese-style salted fish.

There is inadequate evidence in humans for the carcinogenicity of other salted fish.

There is limited evidence in experimental animals for the carcinogenicity of Chinese-style salted fish.

Overall evaluation

Chinese-style salted fish is carcinogenic to humans (Group 1).

Other salted fish is not classifiable as to its carcinogenicity to humans (Group 3).

For definition of the italicized terms, see Preamble Evaluation.

Last updated 08/21/1997

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       Toxicological Abbreviations