Final update
Enhancing the healthy fats in beef
A study at two Teagasc centres (Grange Beef Research Centre and Ashtown Food Research
Centre) showed that grass-fed beef is high in CLA and this can be further enhanced by including
sunflower oil/seed and/or fish oils in the diet of cattle. In addition, researchers at University
College Dublin, fed the CLA-enriched beef to mice and showed that it had protective effects
against diabetes and inflammation, including inflammatory bowel disease and rheumatoid
arthritis. Project code MQ011, final update.
Fatty acids – a hidden potential in meat
There is a common misconception that all fats in
meat are “bad”. Meat contains a mixture of fatty
acids and many are beneficial to health. Conjugated
linoleic acid (CLA), is a fatty acid found in ruminant
products, such as beef. It is thought that CLA has a
number of potential health benefits, including
protection against cancer, diabetes, and heart disease.
There are many different types (isomers) of CLA
with cis 9, trans 11 being a prominent form in beef.
This isomer of CLA is linked to many health
promoting properties and it is known that cattle that
are grass fed have naturally high amounts of CLA.
Raising the CLA content of beef
Cattle were fed one of nine diets (Table 1), and an
explanation for each of these is provided in the
previous
RELAY
update
(MQ011-2
on
www.relayresearch.ie).
Grass fed animals
The researchers detected up to 18 isomers of CLA in
the meats they tested. The predominant CLA isomer
in un-supplemented grass-fed beef was cis 9, trans 11
(this is the isomer with beneficial health attributes)
followed by trans 11, cis 13. Supplementation of
grass with sunflower/fish oil altered this distribution
such that trans 7, cis 9 became the second most
prominent isomer, however, the healthier cis 9, trans
11 was still the main CLA isomer.
Supplementing the grass diet with sunflower seed
Dr Aidan Moloney spear-headed a study across two
and fish oil (Diet 2) had a beneficial effect on the cis
Teagasc research centres (Ashtown Food Research
9, trans 11 content as it was increased by a third.
Centre and Grange Beef Research Centre) and
However, replacing sunflower seed with sunflower
successfully raised the CLA content in beef, by
oil (Diet 4) had an even better effect on the cis 9,
supplementing the diet of cattle with sunflower
trans 11 as it was increased by 50%.
seed/oil, fish oil and vitamin E.
Table 1. Diets of cattle in feeding trial
Concentrate fed animals
1. Grass only
In the concentrate-fed cattle, adding sunflower seed,
2. Grass + sunflower seed + fish oil
fish oils and vitamin E (Diets 6 to 9) to their diet did
3. Grass + sunflower seed + fish oil + 1000 IU
not increase the cis 9, trans 11 isomer of CLA. In
vitamin E
addition, levels of cis 9, trans 11 isomers were about
4. Grass + sunflower oil + fish oil + 1000 IU
a fifth lower in the beef of cattle fed concentrates
vitamin E
than grass.
5. Concentrate, formulated to simulate
Conclusions from the feeding trial
linolenic acid supply from grass
This study shows the important role that grass
6. Concentrate + sunflower seed + fish oil
feeding plays in ensuring that there is a good supply
7. Concentrate + sunflower seed + fish oil +
of CLA (in particular, cis 9, trans 11) in the beef of
500 IU vitamin E
cattle compared to concentrate fed beef. This is
8. Concentrate + sunflower seed + fish oil +
particularly relevant to Irish beef which is
1000 IU vitamin E
predominately grass fed. It also highlights that CLA
9. Concentrate + sunflower seed + fish oil +
3000 IU vitamin E
For more information on food research contact RELAY
T: 025 42321, F: 025 42293, Email: info@relay.teagasc.ie
Final update
can be dramatically enhanced by adding sunflower
oil and to a lesser extent sunflower seed and fish oil.
There was no evidence to suggest that the different
dietary regimes had a deleterious effect on colour or
lipid stability. Despite the fact that trained sensory
panellist’s detected minor changes in the taste of
some of the supplemented meats, the difference was
minor and not a cause of concern.
diabetes as both diets had favourable effects on
number of markers for type 11 diabetes.
Inflammation
Inflammatory conditions include sepsis (serious
medical condition which can lead to organ failure
and death), rheumatoid arthritis and inflammatory
bowel disease
The group induced sepsis in mice that were fed either
a low- or high-CLA beef diet. They found that a
number of markers of inflammation (cytokines, carry
signals about an immune response) reacted positively
in the mice that were fed the high-CLA beef diet.
These results show that beef high in CLA has a
beneficial role in the inflammatory component
associated with sepsis.
Grass feeding naturally enhances the CLA content of
beef, in particular the beneficial isomer of CLA, cis 9,
trans 11.
Searching for health benefits of CLA-rich
beef
Prof. Helen Roche and her research team at
University College Dublin, used a combination of in
vitro and in vivo models at assess if CLA-rich beef
has potential health benefits. They used the CLArich beef from the Grange feeding trials.
Diabetes
Diabetes mellitus type 11 (formerly called noninsulin-dependent diabetes mellitus or adult-onset
diabetes) is a disorder characterised by high blood
glucose due to insulin resistance (body becomes less
responsive to insulin) and insulin deficiency (betacells in the pancreas produce too little insulin for the
body’s needs). It is common in people who take too
little exercise, eat a high-fat/calorie diet and/or are
overweight and its prevalence is on the increase in
Ireland. Type 11 diabetes is initially managed by
increasing exercise and dietary modifications.
However, medications (anti-diabetic medicine and/or
insulin injections) are typically needed as the disease
progresses.
In this study, the researchers fed mice either a diet
containing beef rich in CLA or synthetic CLA. Data
from these studies suggest that CLA-rich beef is as
good as synthetic CLA in protecting against type 11
Similarly, Prof. Roche also carried out a series of in
vitro and in vivo studies examining if beef CLA can
protect on inflammatory processes relevant to
common conditions such as inflammatory bowel
disease, rheumatoid arthritis etc. When mice were
fed the high-CLA beef enriched diet they showed
positive effects on some of the markers of
inflammation.
These mice were resistant to
inflammatory challenges present in common
conditions such as inflammatory bowel disease and
rheumatoid arthritis.
Additional information:
Check out project NU018 on www.relayresearch.ie
as Prof Roche further investigates the protective
mechanisms of beef CLA on diabetes and
atherosclerosis.
Go to Meat matters… workshop (22/10/09) on the
Past Workshop section of www.relayresearch.ie to
download presentation made by Aidan Moloney and
Helen Roche
Contact: Dr. Aidan Moloney, Grange Beef
Research Centre, Teagasc, Dunsany, Co. Meath.
t: 046-906 1100 f: 046-902 6154
email: aidan.moloney@teagasc.ie
Collaborating Researchers: Prof. Helen Roche and
Dr. Frank Monahan University College Dublin; Dr
Peter Dunne, Ashtown Food Research Centre.
This FIRM project is funded
through The Department of
Agriculture, Fisheries and
Food under the National
Development Plan 2007-2013.
Written by Dr Breda Mulvihill, RELAY, November
2009
For more information on food research contact RELAY
T: 025 42321, F: 025 42293, Email: info@relay.teagasc.ie