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The meat of Australia's bush kangaroo may be the
highest known source of the healthy fat CLA, a University of Western
Australia and CSIRO sponsored PhD student has discovered.
CLA (conjugated linoleic acid) is found in dairy
products, beef and lamb.
In trials, CLA has been shown to possess potential
anti-carcinogenic and anti-diabetes properties, in addition to reducing
obesity and atherosclerosis (high blood pressure).
PhD student Clare Engelke has found that the meat-fat
of the Western Grey kangaroo in some circumstances has up to five times
higher CLA content than lamb.
"Australian pastoral lamb is considered to be a
relatively high source of CLA, so I was surprised to find the levels in
kangaroos were that much higher in comparison," Ms Engelke said.
Her study is believed to be the first research on CLA
levels in kangaroos available in the public domain.
In collaboration with the University of Adelaide, Ms
Engelke compared CLA levels in Western Grey kangaroos and lambs from the
Badgingarra region in Western Australia and analysed tissue samples of other
Western Greys, Red and Eastern Grey kangaroos from different areas of
Australia.
Although kangaroos are not a true ruminant, Ms Engelke
became interested in researching Australia's national icon for her PhD in
agricultural science because, like ruminants, kangaroos ferment food in
their foregut. CLA is produced in the stomach and tissues of ruminant
animals such as sheep and cattle during the digestion process.
In Australia, kangaroo meat has traditionally been
used for pet food but the European market for the meat grew by 30 percent
following the 2001 outbreak of foot and mouth disease.
CSIRO Project Leader Dr Andre Wright said kangaroo
meat was very lean with a two per cent fat content.
"Kangaroo meat also has high levels of protein, iron
and zinc," Dr Wright said.
Ms Engelke is now working to identify the 'bugs' in
the kangaroo's foregut responsible for producing CLA.
"My aim is to find out which microorganisms and
circumstances are responsible for CLA formation and why kangaroo meat
appears to be the highest known source of these healthy fats," Ms Engelke
said.
If successful, it may be possible to increase the CLA
content of other meats and products to increase potential health benefits to
consumers.
Edited Betacam footage of Ms Engelke culturing
bacteria in a laboratory is be available at the media conference.
More information:
Dr Andre-Denis
Wright, CSIRO Livestock Industries, +61 8 9333 6417
Media assistance:
Ms Margaret Puls,
CSIRO Livestock Industries, +61 9 9333 6403, 0419 578 356
FREQUENTLY ASKED
QUESTIONS ABOUT KANGAROO MEAT AND CLA
How many kangaroos
are there in Australia?
It is estimated there are around 35 million kangaroos
in Australia. Five of the 48 species of kangaroo are harvested for meat. The
kangaroo meat industry harvests approximately two million animals per annum
and provides employment in regional Australia.
What is the
nutritional composition of kangaroo meat?
Kangaroo meat is very lean and has less than two per
cent fat content. Kangaroo meat also contains very high levels of quality
protein, iron and zinc. Due to its leanness, kangaroo meat must be cooked
with care to avoid overcooking. A doctoral study undertaken by Clare Engelke,
sponsored by the University of Western Australia and CSIRO Livestock
Industries, indicates that kangaroo meat is the richest known natural source
of CLAs in currently available literature. Dairy milk was previously the
highest known source of CLAs, followed by beef and lamb.
What are conjugated
linoleic acids (CLA)?
Conjugated linoleic acids (CLA) are polyunsaturated
fatty acids that have been the focus of researchers over the past two
decades. In animal experiments, CLA have been shown to reduce obesity and
heart disease and have anticarcinogenic properties. The majority of research
into CLA has focused on the health benefits of CLA to humans. These benefits
have only properly been demonstrated in animal models and human cells, not
humans themselves. However, one study in humans detected an inverse
(reduced) relationship between milk consumption and breast cancer risk.
Tests of CLA benefits in humans have been limited by ethical considerations
- for example, the illnesses that CLA are reported to protect against cannot
be induced in human subjects, nor can lifestyle factors be controlled as
easily as with mice or rats in a laboratory. Currently, scientists do not
yet have a definitive answer for the amount of CLA required to produce
beneficial effects in humans.
Where are CLA found?
CLA are found in products made from the meat and milk
of ruminant animals (such as sheep and cattle). Many other foods contain CLA,
including vegetable oils, eggs, seafood, poultry and pork but at very low
levels. The levels of CLA found in ruminant products depend upon the diet of
the ruminant animal, and are generally higher if the animal is grazing on
fresh, green pasture. Australian beef and sheep grazed on a pastoral-based
grazing system are considered to be richer sources of CLA than lot-fed
cattle. Ruminant animals have high levels of CLA because they have bacteria
in their gut (rumen) that produce CLA naturally during digestion of feed and
later in fat tissues.
What are CLA levels
in kangaroo meat?
Kangaroos can have as much as five times more CLA in
their fat than ruminants. The level of CLA in kangaroos depends on their
diet, as it also does in ruminant animals. Clare Engelke, a PhD student, is
studying the level of CLA in kangaroo tissues and attempting to identify the
microbes that produce CLA during digestion and why these CLA occur at
relatively high levels. In collaboration with the University of Adelaide,
she tested the CLA content of Western Grey kangaroos from the Badgingarra
region of Western Australia with lambs and found that the CLA levels in
kangaroos there were up to five times higher than in the lambs.
Kangaroos are not true ruminant animals but, like
ruminants, they ferment feed in their foregut. Ms Engelke also tested
Western Grey kangaroos from other areas of Australia and other species - Red
kangaroos and Eastern Greys. The CLA levels in these kangaroos were high but
varied according to diet, with kangaroos from areas that had fresh pasture
proving the richest source of CLA.
At the time of publishing, there were no other reports
of CLA levels in kangaroo meat. Although there have been reports of
conjugated dienes in quokkas, wallabies and kangaroos, no CLA levels have
been recorded.
Is kangaroo meat good
for you?
Kangaroo is a uniquely Australian game meat that is
lean and healthy with around two per cent fat and very high levels of
quality protein, iron and zinc. Because kangaroo meat is so low in fat
content, the meat must be cooked quickly to avoid overcooking. Kangaroos are
harvested by licensed shooters in accordance with a strict code of practice.
Kangaroo exports are subject to stringent inspection requirements by the
Australian Quarantine and Inspection Service (AQIS) under the Australian
Standard for the Hygienic Production of Game Meat. The discovery of high
levels of CLA (healthy fats) in kangaroos may also increase the health
benefits of the meat.
Who eats kangaroo?
In Australia, most kangaroo meat is currently sold for
use as dog and cat food. However, kangaroo is increasing in popularity in
Australia, with high quality kangaroo steaks available in supermarkets.
Kangaroo meat is also increasing in popularity in Europe, with European
exports rising by 30 per cent following the 2001 UK foot and mouth disease
outbreak. Outbreaks in Europe of mad cow disease have also increased
international interest in kangaroo meat. In 2002, the Balkans imported more
than 2000 tonnes of kangaroo meat, where it is used for steaks, salami or
sausages. |
