They found children taking the daily omega-3 supplement had 58 minutes' more sleep and seven fewer waking episodes per night compared with those on the placebo.

London - Crops genetically modified to produce fish oils could be grown this spring, scientists have said.

Researchers have applied to do the first GM field test in Britain for three years, which if approved could lead to a synthetic form of cod liver oil being sold by 2020.

It would be only the fifth field test in a decade in the UK, with such ‘Frankenstein foods’ viewed with concern. Critics raised fears about hidden health risks.

The scientists say a modified Camelina plant – usually grown as a biofuel or for animal feed – can produce as much healthy omega-3 fatty acid as is found in fish oils.

The plant was made by “cutting and pasting” genes from algae.

Professor Johnathan Napier said: “Fish stocks are in decline so there is a problem of availability of fish for these fatty acids.”

Omega-3 acids benefit the heart, brain and nervous system and may protect against Alzheimer’s.

The crop would initially be used as feed in fish farms, which buy 80 per cent of fish oil supplies. But Professor Napier said by the end of the decade the GM-produced oil could be sold for human consumption as a supplement – if it passed rigorous health tests.

If ministers approve the trial, the seeds will be sown in April.

Geneticist Ricarda Steinbrecher said: “There are more risks than are immediately obvious. Will the plant still produce all its original nutrients? Will it produce toxins?” - Daily Mail