Oils & Fats News October 2006

Functional Lipids Seminar November

The programme is all finalised for this event and registrations are beginning to roll in.

It looks to be a very full and interesting programme so there will be plenty of updated scientific and commercial information for everyone.

The group is offering financial prizes for the student posters as follows

First Prize $500 dollars

Second and Third Prizes $250

We are also planning to offer financial help to deserving students to attend oils and fats conferences. This will be done on an annual basis and for next year the closing date is end January 2007.

For those members who attend the seminar we are offering a 50 dollar discount off the price of the forthcoming book on Edible Oils in Australasia .This book is currently being assembled by the various contributing authors and we anticipate publication in May 2007.

For the seminar in November and registration see the website…

Lecture by Julian Mellentin (New Nutrition Business)

Julian gave a hugely stimulating and informative talk at Auckland University on Friday 6th October .The talk discussed the commercial fortunes of several functional food product launches. These included Plant Sterols, Probiotics and omega-3 products. There were some salutary lessons for the plethora of functional ingredient companies springing up in New Zealand. His books and journal on the marketing and commercial business of functional foods are unique and are a must if you are in this business.

Omega-3 quality in the news

Are omega-3 products really the good oil?

Consumers buying foods with omega-3 may not be getting the good oil they think they are says Rufus Turner, a lipids scientist with Crop & Food Research.

He and colleague, Dr Carlene McLean, have studied commercially available fish oil in New Zealand, that’s been manufactured overseas.  They found it contains varying levels of primary and secondary oxidation products.

“These oxidised products result in variations in the quality of fish oils and may explain the mixed results in international human clinical trials investigating omega 3 health benefits” Dr McLean said.

Recent results from international cellular, animal and human trials indicate that the oxidised  products in fish oils may have potential carcinogenic and pro-inflammatory actions. These products have the potential to increase the risk of atherosclerosis and thrombosis and reduce the potential benefits of omega-3 fatty acids.

Dr Turner says that unfortunately, fish oils containing omega-3 fatty acids are unstable and more vulnerable to oxidation than vegetable oils or other animal fats.  When fish oils come into contact with oxygen and are exposed to metals, light and heat they degrade.  Oxidation of the oil accelerates after extraction from the fish and during subsequent storage.

Dr McLean says New Zealand is at the forefront of research providing solutions for long-term preservation of commercial oil products for human use.  Fish oil producers are working with scientists at Crop & Food Research to ensure New Zealand-produced oil is of the highest quality.

“We are using the by-products from the filleting process, which constitute up to 60% of the fish weight and contain up to 10% oil, to produce a value-added, high-quality nutraceutical oil,” says Dr McLean. “As well as looking at ways to improve handling of the raw material after harvest, we are working with industry to modify their by-product processing operations, to improve yields and the quality of oil and protein extracts.”

Dr Turner says, “It is essential to ensure that fish oil in food products has good levels of omega-3 fatty acids, and that measures have been taken to minimise degradation, so consumers do get the good oil they believe they are purchasing.


Recognition of the health benefits of omega-3 fatty acids has grown since the Inuit Eskimos low incidence of heart disease was highlighted in the 1970s. Their high fat diet is sourced from marine animals and it has now been established that the omega-3 fatty acids found in fish play a unique and important role in preventing heart disease.  See the report on the recent ISSFAL conference which dealt mainly with omega-3.

Many other benefits have also been associated with consumption of fish oils including enhanced immunity, improved bone, joint and eye health and better brain function.  Links have also been made to mental health.

Around the world, food companies have responded to consumer awareness of these health benefits by creating products with omega-3 fatty acids.  These include: breads, spreads, yoghurts and drinks.

For more information contact

Dr Rufus Turner, or Dr Carlene McLean

Crop & Food Research

Tel 03 539 1849


Drs Turner and McLean work on lipids, proteins & their oxidation.  Recent research, at their Nelson base, has focused on the analysis of volatile oxidation products in fish species. This has been achieved using the only Gas Chromatography Mass Spectrometer – SPME dedicated to oils in New Zealand.

Review of ISSFAL conference (Cairns,July 2006)

Controversies and Consensus: ISSFAL 2006 Highlights

Lynley Drummond

The biennial conference of ISSFAL (International Society for the Study of Fatty Acids and Lipids) was held in Cairns, Australia (23-28 July 2006), and this year also incorporated the 6th International Congress on Essential Fatty Acids and Eicosanoids, and PUFA in Maternal and Infant Health 2006 Annual Scientific Meetings.  With a wonderfully  comprehensive range of topics: the role of FA (predominantly PUFA) in cancer, cardiovascular disease, brain composition and function, diet and dietary status, parenteral and enteral nutrition, FA metabolism, pregnancy and lactation, ageing and the brain, eicosanoids, perinatal interventions, to name but  a selection.

It was a conference where one was spoiled for session choice, and even greater dilemma trying to decide on highlights to report.  Several of the most memorable are presented below.

High n-6 LA Diets – Are they good or bad?

The opening debate (High LA diets are bad for your health) was a fitting to begin the Conference, aptly themed “controversies and consensus”.  The debate provided a forum to follow up on the sometimes contentious and misrepresented 1999 Workshop Statement 1 that recommended an upper intake of 3.0% energy for LA, and the 2004 ISSFAL Policy Statement that recognised that whilst there may be a possible healthy upper limit on LA intake there is currently insufficient conclusive scientific evidence to establish such limit.  After a mix of serious and not-so-serious arguments, in line with the ISSFAL policy statement there was no definitive outcome.

The level of dietary n-6 LA theme continued with the 2006 Alexander Leaf Distinguished Scientist Award for Lifetime Achievement awarded to Dr William (Bill) Lands.  The Award lecture a fitting follow-up to the debate.  Dr Lands presented a compelling address identifying mechanisms and pathways of eicosanoid action, in particular the risk of a range of health disorders resulting from overproduction of the n-6 eicosanoids as result of dietary imbalance of n-6/n-3 EFA.  An eloquent presentation which included the mode of action of common medicines such as aspirin, ibuprofen and statins in conditions that all include excessive n-6 eicosanoid signalling.  An advocate for long-term dietary approach (balanced n-6/n-3 ratio) to  prophylactic treatment, Dr. Lands book “Fish, Omega-3 and Human Health” (2nd Edition, 2005 AOCS Press) provides an extensive background as a remarkably enjoyable read, and comes highly recommended.    He is also a key contributor to the website to which I further highly recommend a visit for those interested in the topic.

The use of n-3 PUFA in particular for the treatment of a wide range of disorders (cancer, inflammatory, cardiovascular, neural decline/ dysfunction) was a continued theme with research updates reporting a range of outcomes.  For example, one UK researchers presented the results of a 6 month dietary intervention that evaluated the effects of modifying the n-6/n-3 ratio on plasma lipids, lipoproteins, and membrane composition.  The outcomes suggested that it was the absolute intake of dietary fatty acids, not the n-6/n-3 ratio that had the strongest effect in predicting favourable plasma lipid and lipoprotein outcomes.  A possible explanation of the variable outcomes of different interventions was hypothesised with the results of another UK intervention trial that showed genotype has a major impact on a person’s responsiveness to the hypotriglyceridaemic benefits of fish oil, attributed to DHA and EPA.  Carriers of the apoE4 allele are less responsive to the beneficial effects of these n-3 LCPUFAS, and in fact previously the reported hypercholesterolaemic effect observed in some studies of may result from a LDL raising effect of DHA in carriers of that allele.

Beyond n-3 PUFA as we now know it.

With the multiplicity of health benefits that n-3 FA offer, the demand for them is growing. To answer potential long term limitations in n-3 FA supply, acknowledging the abundant supplies of n-6, and the inability of most species, including mammals, to convert n-6 to n-3 a genetic approach has been developed to address these issues, and to deliver a balanced tissue ratio of n-6/n-3 FA.  Identification of the fat-1 gene in the nematode Caenorhabditis elegans has enabled the development of genetic model that modifies the tissue EFA balance by converting n-6  to n-3.    Researchers have developed both mammalian cells and animals that express the humanised fat-1 gene.  Transgenic mice and pigs are able to effectively produce n-3 FA from n-6 FA, with a resultant balanced n-6/n-3 ratio in tissues, without exogenous n-3 supplementation.  The potential for land based animal livestock as a renewable source of n-3 FA is one benefit suggested, however the immediate benefit is that these transgenic animals are useful models for the study of the roles that n-3 FA have in mammalian metabolism, with a key advantage being that experiments are free from diet related confounding factors.  One study using the fat-1 mouse model to investigate changes in the hippocampal and whole- brain at the mRNA and protein level reported specific changes that can be explained by the shift in n-6/n-3 balance of brain lipids.  Another research group reported the outcome of their investigation into the effects of fat-1 enzymic activity on the retinal chemistry and function of fat-1 mice, reporting significant increases in the n-3LCPUFA composition of retinal tissue; however this was accompanied by a greater loss of photoreceptors following light stress.

Phosphatidylserine (PS) is well documented for its efficacy in slowing or mitigating cognitive function, and there are a number of reports of the benefits of PS containing DHA for a range of mental dysfunctions (dementia, depression, age-associated memory impairment).  Similarly most of us are well familiar with the critical functions of the phospholipids in membrane function.  Traditionally prepared from bovine brain cortex, the PS-DHA, has more recently been isolated and prepared from squid phospholipids, as well as via interesterification processes, avoiding potential BSE issues.  In a recent study of the effect of PS-DHA on the improvement in learning of n-3 deficient mice, significant improvements were seen only in the PS-DHA group, compared to those fed standard DHA, soy PS, and  Soy PS + DHA.  The researchers concluded that PS-DHA is more effective in restoring brain function associated with DHA deficiency and that it may be a better lipid supplement that either fish oil or soy PS for such purpose.  In a murine model where pregnant mice were fed supplemental DHA, PS-DHA coupled with ALA was shown to be more efficient than fish oil based DHA for the accumulation of DHA in the foetal pup brain.

Infant Nutrition

The role of LCPUFA in infant nutrition, infant growth and development (including the importance pre- and perinatal maternal nutrition) continues to be an area of significant and on-going research.  Whilst there were a number of reports of the beneficial effect of LCPUFA in infant nutrition, several key messages from the conference include:

-          the continued requirement for large scale clinical randomised controlled trials with follow-up

-          the need to standardise at least a basic set of biomarkers and measures for these trials so that long term the trials can be compared in systematic reviews

-          the AA:DHA ratio typical of IF may not be ideal – studies of term baboon neonates indicating that those fed formula with 3 times the typical DHA level had enhanced DHA concentration in critical areas of the brain and that the DHA/ AA ratio influences the expression of a broad range of genes in the brain and liver.

-          the potential role of PUFA in stimulation of the systemic immune response.  Using a murine vaccination model, researchers were able to show that PUFA supplementation of formula resulted in enhanced systemic immune responses, similar to effects reported for other IF ingredients such as oligosaccharides.  The ability of PUFA, as fish oil, to stimulate a more rapid development of immune function as measured in 9 to 12 month old infants was determined in a Danish intervention trial.

One surprising and disappointing aspect of the conference was the relative dearth of papers on other bioactive lipids, such as gangliosides in infant nutrition, especially given that this is an area of significant interest by many organisations.  Although briefly mentioned in several of the plenary lectures, only one paper specifically addressed the potential role of these more complex lipids – focussing on the potential mechanisms and role in improving neonatal bowel survival in instances of NEC (necrotizing enterocolitis).

What is most apparent from the vast array of topics raised at this conference is that the study of fatty acids and lipids is seemingly just in its infancy when we try to understand the mechanisms of their action in metabolism and the potent effects that they have on human health.  In this day when we are all well of the adverse health effects of trans fatty acids, the promotion of CLA provides and interesting juxtaposition – a topic explored in the appropriately titles session “ What are the health effects of trans fat and CLA?  All bad for industrially produced trans fat, and both good and bad for CLA”.  Controversies are sure to endure, consensus remaining the ultimate target.  Meanwhile if you can measure the impact of a conference by its ability to make a change in you dietary habits then this conference is certainly up there – never again will I be without a daily dose of DHA.  The evidence, I think, is convincing.

1.            Simopoulos AP, Leaf A, Salem NJ. Workshop Statement on the Essentiality of and Recommended Dietary Intakes for Omega-6 and Omega-3 Fatty Acids. Prostaglandins Leukot Essent Fatty Acids. 2000;63(3):119-121.

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