The study acts as a public call to action, recommending that we need to treble our RDA of Omega 3 fatty acids to help prevent the onset of conditions such as eczema in babies and young children and rheumatoid arthritis in adults. Fish oils can directly help prevent such conditions, in addition to aiding the prevention of post-natal depression and promoting positive child development, yet the UK's intake has fallen by 8% since the 1970's.

It reveals that Omega 3 fatty acids, which can't be made properly in the body, are essential to pregnant mums, yet most are still not getting enough:

• proven to help reduce post-natal depression
• taken during 2nd half of pregnancy – babies have lower allergy related cells, plus lower asthma and eczema risk
• help aid normal eye and brain development
• benefit baby's immune system
• lead to improved child development – higher mental processing across early childhood

Omega-3 fatty acids found in fish oils can help people cut their risk of inflammatory conditions, such as eczema and rheumatoid arthritis, says a new scientific review. But too few people are getting the optimal level of these essential nutrients.

The major benefits of fish oils in helping to prevent cardiovascular disease and heart attacks are now widely accepted. But a new scientific review of omega-3 fatty acids and health commissioned by the Health Supplements Information Service (HSIS) shows the advantages are even more far reaching. This review is set to be published in the latest issue of the journal – Nutrition and Food Science.

The research also suggests that women who take fish oil capsules during pregnancy and while breast feeding may reduce the risk of asthma and eczema in their babies and aid normal brain and eye development. Some studies also find that post-natal depression can be helped by a fish oil supplement. Later in life, omega-3 intake appears to help slow down age-related cognitive decline in healthy elderly people and reduces the risk of dementia. There is also emerging evidence that diets rich in fish oils could protect against the development of bowel and breast cancer.

Yet most of us eat far too little oil-rich fish and, as the body doesn't manufacture the most helpful omega-3 fats at a fast enough rate, many of us could be deficient in omega-3s. However, if we trebled our intake of oily fish to meet health requirements it could have a negative effect on the world's marine life. That is the harsh warning in a paper by leading independent dietitian, Dr Carrie Ruxton, and senior lecturer in Human Nutrition at Manchester Metropolitan University, Dr Emma Derbyshire, which analysed the current evidence surrounding omega-3 sources, intakes, recommendations and their impact upon health.

"The benefits of consuming omega-3 are clear and there is sufficient evidence on heart health and immune function to continue promoting increased omega-3 consumption across the lifecycle," said Dr Ruxton. "There is also steadily growing evidence pointing to a distinct benefit for foetal programming via increased maternal omega-3 intake during pregnancy.

"The majority of evidence linking omega-3 with health benefits derives from studies of fish or fish oils, and this naturally translates into advice to consume more oily fish. "However there are concerns that a heavy reliance on the world's oceans to meet increased demands for fish oils could have negative consequences for the marine environment. Health issues have also arisen since a few species of fish (fresh tuna, marlin, swordfish) can contain heavy metals or organic pollutants."

Regular intake of white fish – the Food Standards Agency (FSA) recommends eating two portions of fish a week, one of which should be an oily fish such as sardines, mackerel or salmon – has fallen by 8% since 1974, while household consumption of oily fish has only risen by 4.7% according to the UK National Diet and Nutrition Survey. This is well below the FSA guidelines of between 0.2g and 0.45g per day.

Fortified foods are an alternative dietary source of omega-3 but levels can be too low in some products. And, although we eat large amounts of beef, pork, game and poultry, the omega-3 content is limited due to changes in farming practices which means that pigs and poultry are now fed predominantly manufactured vegetarian feeds rather than the fish oil and fish meal of the past.

Evidence supporting benefits of omega-3 for patients with rheumatoid arthritis showed that supplementation with the omega-3s, EPA and DHA , for three to four months was associated with less reported joint pain, morning stiffness, tenderness and use of non-steroidal anti-inflammatory drugs (NSAID). In another study symptoms in patients with atopic eczema improved significantly after taking omega-3 supplements for eight weeks. The randomized double blind controlled study compared patients consuming either 5.4g DHA per day or a placebo. More evidence is now needed to confirm this.

Research also showed that babies born to mothers who had taken omega-3supplements during the second half of pregnancy had a significantly lower number of allergy-related cells, less inflammatory response to allergens and a reduced risk of asthma and eczema. Improving the omega-3 levels in breast milk also delivered immune benefits to infants. In further trials, four-year-old children whose mothers had taken cod liver oil capsules (containing DHA and EPA) during later pregnancy scored considerably higher on mental processing tests than children whose mothers had taken corn oil placebo capsules. The benefits were still evident when the children were seven years old.

"Supplements are often used as alternative sources of omega-3 by people who cannot meet requirements from food sources alone," said Dr Ruxton. "Food fortification can also contribute to omega-3 intakes but this depends on the type of omega-3 used (fish oil sources are best) and how much is added to the products – many are too low. Research confirms that omega-3 from supplements can significantly increase nutritional status and benefit health."