Fish Oils are the new health 'wonder' food - not a week goes by, it seems, without yet more research confirming how good they are for you.

Not only do they help children with learning difficulties (..), fishoil protect the heart and reduce the pain of arthritis.

Then last week a study, funded by Boots, found that regular doses of fish oils dramatically boosted young children's performance at school. Nearly three quarters of the youngsters - who were a mix of academic ability - showed improvements in numeracy, reading and writing after taking fish oil supplements for nine months.

'With no placebo group, we don't know what progress they would have made anyway' says Alex Richardson, a Senior Research Fellow from Oxford University. 'But these findings are in line with other evidence that fish oils really can improve behaviour and learning in many children.'

It is the Omega-3 fatty acids - specifically EPA and DHA - they contain that make fish oils so benificial. Unfortunately the body can't make Omega-3s; the best source is oily fish. But the problem, as most parents know, is that children don't like it, so Omega-3 supplements are becoming a popular option.

Traditional cod liver oil is not particular rich in EPA and DHA; it also contains the fatsoluble vitamins A and D, that can be toxic in excess, so high doses are not advisable in the long-term. Some fish-oil supplements also contain these vitamins so ask your GP before attempting to increase dosage.

There is no clear rule about how much EPA and DHA your child should take. 'About 450-500 mg per day combined EPA/DHA is a reasonable target' says Alex Richardson. 'Some may need even more to see real benefits - but I wouldn't recommend more than 1000 mg without expert supervision.

There should be no serious danger of your child over-dosing on fish oils, but an excess can cause a stomach upset, and some people may be allergic to them, so discuss any worries with your doctor.

Taste is a key factor, you need to choose a supplement that is palatable. 'Many of the supplements contain artificial sweeteners, coulorings and flavourings which should not be necessary' says Dr. Richardson. 'Xylitol and mannitol are two of the better sweeteners as they are good for the teeth.'

To help you choose the right fish oil supplement form the bewildering range available, we asked Alex Richardson to analyse their content, while Alex Morrison, 13, his sister Anoushka, 11, and brother Joshua, six offer their verdicts on the taste on a five star rating.

Daily costs quoted are given both for the manufacturers' recommendations and for the dose needed to provide at least 450-500mg of EPA and DHA.