Professorial Lecture Series

"Oils aint Oils..the importance of fats from seeds, leaves and meats "

Professor Tony Hulbert

Wednesday 14th March 2007 (12:30-1:30pm), Location: 20.2

If you missed the lecture - please note that recordings are available. 

There are four types of fatty acids: saturated (SFA), monounsaturated (MUFA), omega-6 polyunsaturates (n-6 PUFA) and omega-3 polyunsaturates (n-3 PUFA). Animals can synthesise saturates and MUFA from non-fat sources but are unable to synthesise both types of PUFA which must be obtained preformed in the diet. Once ingested they can be elongated and further desaturated but not converted to the other fat types. Plants synthesise both types of PUFA and as a generalisation store them as n-6 PUFA in their seeds and as n-3 PUFA in their leaves. Cell membranes are made of fats and studies in animals have shown that membrane composition has important influences on membrane-associated proteins (such as pumps, hormone receptors, neuroreceptors etc.,) and consequently cellular metabolic rate. In general, membrane composition is regulated regardless of the type of fats in the diet, but membrane composition is responsive to the balance between n-6 PUFA and n-3 PUFA in the diet. Indications are that early humans had an approximately equal balance of n-6 and n-3 PUFA in their diet but that in recent times, the modern human food chain has emphasised n-6 PUFA at the expense of n-3 PUFA. This seems to be particularly advanced in many western countries. For example in 1995, the PUFA intake by Australians averaged 90% n-6 PUFA and 10% n-3 PUFA. Common foods and meals vary dramatically in their PUFA balance. It is suggested that the changes in the PUFA balance of the food supply has resulted in changes in the PUFA balance of dietary intake of a substantial segment of the population with many deleterious health consequences due to changes in membrane composition. An over abundance of n-6 PUFA in the diet (at the expense of n-3 PUFA) is a likely cause of insulin-resistance and the conditions of the metabolic syndrome (obesity, hypertension, blood dislipidemias etc.,). More provocatively, it is also a likely cause of increased incidence of several diseases associated wit inflammation (such as Crohn's disease), as well as mental health conditions (including depression and possibly also violent behaviour). If this hypothesis is correct it has huge implications for our modern food chain andit's effects on our health via our  diet. 

Prof. Hulbert is with the School of Biological Sciences, Faculty of Science and is this year's winner of the highly-prized Clark Medal.

Awarded by the Royal Society of New South Wales (Australia) for distinguished work in the Natural Sciences since 1878, this is the first time the medal has gone to a University of Wollongong scientist . It was formerly announced at a Royal Society event in Sydney on Friday night (9th March 2007) that Professor Tony Hulbert would join an honour board of the most noted scientists Australia has produced. Professor Hulbert has been rewarded for his research into the zoo-physiology of a wide variety of Australian animals which includes important implications for both obesity and ageing.