Background/Aims: The recommendations on the intake of long chain omega-3 polyunsaturated fatty acids (n-3 LC-PUFA) vary from eating oily fish (‘once to twice/week’) to consuming specified daily amounts of EPA and DHA (‘250–500 mg/day’). It is not known if there is a difference in the uptake/bioavailability between these two feeding strategies. In this study, the bioavailability of a daily dose of n-3 LC-PUFA (Constant treatment) versus a large weekly dose of n-3 LC-PUFA (Spike treatment) was assessed.
Methods: Six-week old male Sprague-Dawley rats were fed either a Constant, a Spike or Control treatment (no n-3 LC-PUFA), for six weeks. The whole body, tissues and collected faeces were analysed for fatty acid content.
Results: The results showed that the major metabolic fate of the n-3 LC-PUFA was towards catabolism (β-oxidation) accounting for over 70% of total dietary intake, whereas deposition accounted less than 25% of total dietary intake. It was found that significantly more n-3 LC-PUFA were β-oxidised when originating from the Constant treatment (84% of dose), compared with the Spike treatment (75% of dose). Conversely, it was found that significantly more n-3 LC-PUFA were deposited when originating from the Spike treatment (23% of dose), than from the Constant treatment (15% of dose).
Conclusions: These unexpected findings show that a large dose of n-3 LC-PUFA once per week is more effective in increasing whole body n-3 LC-PUFA content compared with a smaller dose delivered daily.
Funding Source: The Molecular Medicine Strategic Research Centre, Deakin University