Abstract:
The consumption of fish oil provides numerous speculated health benefits due to the presence of long
chain omega-3 polyunsaturated fatty acids (PUFA). These health benefits may be challenged by the
presence of heavy metals in fish oil. The objective of the present study was to compare the health
benefits of omega-3 fatty acids and assess the risk of some heavy metals in fish oil extracted from
marine fish. Sixteen species of fish were collected (n=3) from the Trincomalee fish market and fish
oils were extracted using standard Bligh and Dyer method. Fatty acid composition of extracted fish
oils were quantitatively determined by Gas Chromatography - Mass Spectrometry (GC-MS). The
Arsenic (As), Cadmium (Cd) and Lead (Pb) contents were determined by using Inductively Coupled
Plasma - Mass Spectrophotometer (ICP-MS). The amount of fat present in fish varieties was varied
over a wide range of 0.619% (Acanthocybium commersoni) to 8.626% (Carangoides fulvoguttatus).
Among these species, the omega-3 content ranged from 7.814% - 31.818% of total fatty acids and the
highest of omega-3 content was showed in Hemiramphus sp. (9.20 mg/100 g) and lowest level was
reported in Auxis thazard (0.036 mg/100 g). In all species studied, Eicosapentaenoic acid (EPA) and
Docosahexaenoic acid (DHA) are the major omega-3 fatty acids and amounts of EPA and DHA have
been exceeded 70% of the total omega-3 PUFAs. The content of As in extracted fish oils were
ranged from 2.4353-18.3975 mg/kg in Nemapteryx caelata and Elagatis bipinnulata while Cd
content were varied from 0.0262 - 1.2305 mg/kg in Scomberomorus commersoni and
Nemapteryx caelata respectively. Platax sp. reported the lowest Pb content (0.467 mg/kg) while
Acanthocybium commersoni reported the highest (2.282 mg/kg). Some of the fish oil samples had
exceeded recommended human daily intake values of heavy metals, thus benefite of omega-3 fatty
acids is challenged.
Keywords: Fish oil; Omega-3 fatty acids; Heavy metals; GC-MS; ICP-MS
