[ASC-media] Media release: secrets of longevity

JCA Media jcamedia at starclass.com.au
Sat Aug 14 10:10:23 EST 2004


August 14, 2004


Australian scientists are hoping the Naked Mole Rat can tell us how fast we are ageing as individuals.

Professor Tony Hulbert of the University of Wollongong, a comparative physiologist, is studying a variety of animals, including mammals, birds and reptiles, to gain an understanding of the process of aging.

An unlikely research partner in the project is a little-known animal called the Naked Mole Rat, which has the distinction of being the longest lived of all rodents, sometimes reaching the unusual age (for a rodent) of 28 years.

 "Human beings are not the biggest of mammals, but we are the longest lived," says Professor Hulbert. "We can expect a very long life: 120 years maximum, compared with an elephant at 80 years maximum, a blue whale 115 years, and a mouse which dies of old age at three."

Professor Hulbert and his team have established that different species of mammals regulate the composition of the membranes which surround body cells, and occur within the cells, in different ways.

"Mice have a much quicker metabolism than elephants," says Professor Hulbert, "in fact their metabolic rate is over 20 times quicker per gram of mouse than per gram of elephant. 

"This is because cell membranes in smaller creatures are made up of poly-unsaturated fats. In larger creatures, there is a much higher proportion of mono-unsaturated fats," he says.

This discovery has led to what he calls the 'Membrane Pacemaker Theory'.

However the polyunsaturates in the cell membranes of small species are particularly prone to damage by oxygen free radicals. This explains why they do not live as long as large species.

The Naked Mole Rat is an unusual subterranean rodent which - the theory suggests - owes its longevity to the fact of its cell membranes being low in poly-unsaturates but rich in mono-unsaturated fats. Professor Hulbert intends to visit a captive colony of the Naked Mole Rat in New York to determine if this is the case.

Professor Hulbert says that a measure of how quickly we age could be a result of his research project.

"The break-down of membrane fats in normal metabolism produces minute quantities of hydrocarbons such as ethane and pentane," he says. "These are breathed out and could be measured to provide an indicator of metabolic processes, and so of aging."

Professor Hulbert notes that, although it is not possible to manipulate the proportion of poly- or mono- unsaturated fats in the membranes of the body's cells, it is certainly possible to improve the balance between poly-unsaturated Omega 3 and Omega 6 fats, and by increasing Omega 3 fats, reduce Omega 6, a prime cause of obesity.

There is a simple method, says Professor Hulbert: 

"Eat more greens."

Professor Hulbert is one of more than 160 eminent Australian scientists available for interview about their work and science in general during National Science Week. For details visit: www.scienceweek.info.au

To contact Professor Tony Hulbert: phone 02-4221 3437, 02-4268 4045 (a.h.)

For more information on National Science Week:
Telephone: 02 6205 0281
Mobile: 0407 781 891
Facsimile: 02 6207 0072
E-mail: scienceweek at orac.net.au

For more events in National Science Week 2004, please visit:

National Science Week is supported by the Commonwealth Government Department of Education Science and Training (DEST) and the Department of Industry Tourism and Resources (DITR).

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