Fish livers have been confirmed to be a good source of polyunsaturated fatty acids beneficial to health by researchers at the University of Almeria in Spain.
Anchovies are one of the fish whose livers contain the highest levels of these substances.
"The livers of edible fish are a good source of long-chain polyunsaturated fatty acids (LCPUFA), especially those in the omega 3 family, such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)," said Jose Luis Guil-Guerrero, lead author of the study.
These fatty acids are used to prevent and treat various complaints, such as some kinds of cancer, depression, Alzheimer's disease, schizophrenia, behavioural problems and cardiovascular diseases.
The study focused on 12 kinds of fish that are commonly eaten in south eastern Spain, such as hake, shortfin mako and European pilchard. The livers of the great weever (Trachinus draco) and the European anchovy (Engraulis encrasicolus) were those that showed up the highest levels of LCPUFA.
In addition, all the species had a combination of omega-3/omega-6 acids that was "beneficial for human consumption", especially in the case of the liver of the blue whiting (Micromesistius poutassou).
"Unfortunately, discarding these livers means that all their nutritional properties are missed", said Guil-Guerrero, "and if they were used this would also reduce the environmental pollution caused by throwing innards into the water, which is an inherent problem in the fish product processing industry in coastal areas".
The study has been published in the Journal of Food Composition and Analysis.