A British nutritional research scientist says that fish and seafood are still the "best sources" for the fatty acid that can tackle depression and treat children with educational and behavioural disorders.
Many supplements and capsules are no substitute for seafood itself, according to Dr Alex Richardson, Oxford-based senior research scientist and director of the British charity, Food and Behaviour Research.
Children in particular should be eating fish two to three times a week for "multiple advantages" in cognitive development and general health, she said.
Dr Richardson is one of a number of contributors to the World Seafood Congress - including a special debate on Omega-3 - which Minister for Agriculture, Fisheries and Food Mary Coughlan is due to open in Dublin today.
The Oxford scientist published a study last year which found that children with educational and behavioural challenges showed significant improvements after taking fish oil supplements over a three- to six-month period.
The Oxford-Durham study involved mainstream school children with a range of difficulties.
Half were given a placebo and half given Omega-3 supplements, which are known to be rich in eicosapentaenoic (EPA) and docosahexaenoic (DHA) fatty acids.
More than 12,000 assessments were undertaken on motor function, reading and spelling and teacher-rated attention symptoms.
After three months, the active group supplementing with Omega-3 fatty acids saw significant improvements in reading as well as writing, and a significant reduction in attention-related difficulties. There was no such improvement in the group on placebo trials.
Dr Richardson says research is showing that deficiencies in Omega-3 vary in impact from person to person, and that those most vulnerable are those most genetically predisposed to high intakes.
"As scientists we now suspect this may include people with dyslexia, dyspraxia, autistic spectrum disorders, ADHD and depression.
"All of these symptoms are on the increase in the western world - and a general lack of Omega 3 in the diet is one possible reason for this."
"Ireland is surrounded by fish, but it is getting harder and harder for people to buy," Dr Richardson said.
Only 20 per cent of the Irish population eat fish weekly on a regular basis.
Oily fish such as salmon, trout, mackerel, sardines and anchovies are the best sources, but those who do have to purchase supplements should ensure that both EPA and DHA are listed as contents, she advises.
Omega-3 from vegetarian sources has to be converted by the body into EPA and DHA, but lack of vitamins and minerals can complicate this, she says.
The World Seafood Congress opens today at the Croke Park conference centre in Dublin.
Dr Richardson will speak at a public debate on how Omega-3 fatty acids affect nutrition and health on September 27th.
The session will be chaired by RTÉ broadcaster Miriam O'Callaghan.
