You may have seen press coverage linking a high intake of Omega-3's (unsaturated fatty acids) with health benefits such as reduced rates of depression, cardiovascular disease and even increased IQ in newborn babies.

The food industry has responded in recent years and latched on to the suggested health benefits by putting Omega 3's into products as diverse as baby milk, margarines, even processed foods like fish-fingers.

Sometimes called "functional foods", everyday foods with implied health benefits are increasingly becoming big business.

But are all Omega 3's really that good for you?  Omega 3's are generally categorised as 'long chain' and 'short chain' fatty acids.  The really good ones, the 'long chain' ones, usually come from sources such as fish, particularly oily fish, like mackerel or salmon.  'Short chain' Omega 3 acids, like the ones found in soya, flax seed and some green vegetables, have fewer health benefits.

Even if enough (and there's much debate about the right amounts for optimum health benefits) 'long chain' rather than 'short chain' Omega 3's are ingested, their effect may be reduced by everyday oils like olive oil, sunflower oil and most seed oils (Omega 6 oils), which many people use to reduce saturated fat intake, as they effectively 'compete' in the body.

The best nutritional guidance to get the most out of Omega-3's is probably to try to eat less fat (even small reductions can make a difference) and to try and get as much of it as possible from fish.  Supplements may well be a simple step for some people, although they're probably a waste of money if they contain Omega 3's and Omega 6's together.