‘Apparently, it is possible to have a satisfactory level of marine fatty acids in your body without eating fish. We don’t quite understand why,’ says Marian Kjellevold, scientist at the National Institute of Nutrition and Seafood Research (NIFES).
Marine fatty acids in the blood without eating fish and seafood
A study headed by Norwegian scientists that examined 300 children and breastfeeding women in Bhaktapur in Nepal found good levels of the marine omega-3 fatty acids DHA and EPA in both mothers and children. This finding is very surprising since Bhaktapur is nearly 1,000 kilometres away from the ocean, and since the diet of the women and children studied hardly contains any fish or seafood.
In Norway and Europe, fish and seafood is the most important source of marine omega-3, and the scientists therefore expected to find completely different levels of such fatty acids in people who do not eat fish.
‘It was very surprising. We thought that since the Nepalese do not have fish as a source of omega-3, their levels of the marine fatty acids DHA and EPA would be low. But that was not the case,’ says scientist Sigrun Henjum from Oslo and Akershus University College of Applied Sciences (HiOA).
Marine fatty acids are crucial to growth and development
Omega-3 fatty acids are very important to children’ growth and the development of the brain. In Norway, and elsewhere in Europe, a clear connection has been identified between the amount of fish and seafood people eat and their levels of fatty acids. The scientists do not have a clear answer to why this connection is not found in Nepal.
The scientists believed that cooking oil could be the source of the beneficial fatty acid levels, since more than half of the mothers’ fat intake comes from such oil. However, after investigating the matter more closely, it was found that the cooking oil contains very little plant-based omega-3, and so cannot be the source.
‘We are dealing with something we neither see nor understand. It is tremendously exciting,’ says Kjellevold.
Genetically adapted to low seafood consumption?
Part of the explanation could be that the mothers and children in the study also consumed little omega-6, which improves the body’s conversion of plant-based fatty acids into omega-3 fatty acids. That does not explain all aspects of this conundrum, however. To make matters even more mysterious, it turned out that even the babies who are fed exclusively on breast milk had good levels of marine fatty acids in their blood, despite the milk they consume containing very little of these very fatty acids.
‘We can only speculate, but we are wondering whether there could be genetic factors at play here. Could it be that the Nepalese through many generations have consumed so little marine ingredients that they have become genetically adapted? What is certain is that, unlike us, the Nepalese have satisfactory levels of marine fatty acids in their blood without eating fish and seafood,’ says Henjum.
• The article ‘Erythrocyte fatty acid composition of Nepal breast-fed infants’ was written in collaboration between, among others, Innlandet Hospital Trust (Tor A. Strand), HiOA (Sigrun Henjum) and NIFES (Marian Kjellevold)