Well – there’s a surprise! After years of being told that fish oils are great for the mental development of children and postnatal depression, the latest study reported in the Journal of the American Medical Association tells us that this ain’t necessarily so (1). This latest report is especially significant as it comes from the same group who first suggested an apparent link between postnatal depression and the omega-3 fats in fish oils nearly 7 years ago (2). No doubt scores of women have taken fish oils since, persuaded by glossy brochures and the internet that here was a scientifically based “cure” for their postnatal blues. In the latest study, the same authors have also reported that the omega-3 fats in fish oils taken by pregnant women do not improve mental or language development in their babies. They also report in a separate study that higher doses of fish oils in premature babies had no effect on later language development (3).
What to make of all this? Now there is no question that two of the fats in fish oils, EPA and DHA (the full names and descriptions are in our previous blog “Something fishy with Fish Oils: Part 1”), are essential for the growth and development of the brain. We know that because DHA in particular is present in large amounts in both adult and infant brain. However, this does not necessarily mean that we need to take an EPA or DHA supplement, which are essentially fatty extracts of fish, just to make sure that our babies have enough EPA or DHA. So again, where does the truth lie and what constitutes “honest” marketing?
A Chinese proverb tells us:
“We see what is behind our eyes”
The companies selling fish oil supplements and scientists who are working on fish oils and in some cases act as consultants for and may receive research funding from the industry, have a vested interest in fish oils. This creates a potential conflict of interest whether they are consciously aware of it or not. So do they, like every one of us, also see what is “behind their eyes”? A reasonable diet with a good intake of fish will provide sufficient EPA and DHA for both you and your developing baby. Yet, is this the message we are getting from the media and the marketers? Are we getting messages from the advertising industry that we are “bad” parents if we don’t take fish oils? And who could blame a mother to be for believing they are doing the right thing for their baby by taking fish oils while they are pregnant? Are we also told that dozens of trials have been carried out to determine whether fish oil supplements are beneficial for infants and that there are striking inconsistencies in the results of these trials? The reports mentioned above illustrate this fact very well. Apart from the financial costs of taking fish oils, consumers should be aware that fish oil supplements are hardly natural and that the processing methods to get the oils out of the fish may be quite severe and may alter the chemical composition of the mixture. There is another thing, something that needs to be addressed by the appropriate regulatory authorities but seems to be a political “hot potato” that no-one wants to touch: Fish oil supplements contain scores of different fats and other substances which probably vary according to the type of fish, where the fish were caught, the time of year the fish were caught and the manufacturer. All of which are likely to influence any efficacy the oils may have.
While fish oils have proven health benefits in certain circumstances, Promoting Good Health is concerned about the many claims made for fish oils. And we are not alone – see the reference to “The Emperor’s new pills” in our earlier blog. We are also concerned by the inconsistencies in the research findings which many consumers may not be aware of. To bring some clarity to the area we have written a book on the topic “Fish Oils – Everything You Want to Know”. In this eBook we talk about what fish oils are, how they are made, what is in the capsules you buy, what the claims are, whether there is any basis for these claims and any potential side effects, so that you can make an informed decision as to whether to take them or not. We hope this eBook will help you separate the facts about fish oils from the hype.
Until next time, stay happy and healthy.
(1) Makrides M et al (2010) Effect of DHA supplementation during pregnancy on maternal depression and neurodevelopment of young children: a randomized controlled trial. JAMA 304, 1675-1683.
Abstract available at: http://www.ncbi.nlm.nih.gov/pubmed/20959577 
(2) Makrides M et al (2003) Docosahexaenoic acid and post-partum depression – is there a link? Asia Pac J Clin Nutur 12 Suppl S37
Abstract available at: http://www.ncbi.nlm.nih.gov/pubmed/15023646 
(3) Smithers LG et al (2010) Feeding preterm infant milk with a higher dose of docosahexaenoic acid than that used in current practice does not influence language or behaviour in early childhood: a follow up study of a randomized controlled trial. Am J Clin Nutr 91, 629-634.
Abstract available at: http://www.ncbi.nlm.nih.gov/pubmed/20053878