Omega 3 fish oil contains two active ingredients: EPA (Eicosapentaenoic Acid) and DHA (Docosahexaenoic Acid). Most fish oils on the market contain both these ingredients in various quantities - the argument that has arisen concerns which of these essential nutrients you need, and which is better than the other.

DHADHA is now thought to constitute the ‘building blocks’ of the brain, forming about 8% of the brain by weight - this is why it is important for pregnant mothers to ensure an adequate supply throughout pregnancy.

EPAEPA however is different; this essential nutrient is now considered by some leading doctors and professors in the UK as being the single most vital nutrient in the functioning of the brain and nerve stimulation.

According to the professor, this is backed up by two randomised controlled trials at the University of Baylor and Sheffield, where depressed people who were given DHA only fared slightly worse than the placebo-controlled group.

A good example of this would be with flaxseed oil, that is high in the omega 3 parent fatty acid ALA (alphalinoic acid); to obtain roughly 1 gram of EPA, you would have to ingest 11 grams of flaxseed oil.