Consumers have shown considerable interest in “healthy fats” and “bad fats” in recent years. The potential health attributes of conjugated linoleic acid (CLA) and omega-3 fatty acids have led to considerable media focus, marketing opportunities and consumer confusion.
Stores now place omega-3 labels on fish, yogurt, eggs and bagels. Beef contains both omega-3’s and CLA’s, but you will not find these labels on beef products because the current levels of omega-3’s do not meet the minimum requirement for a nutrient content claim, and there is no official health claim for CLA in Canada.
CLA
CLA’s are naturally produced trans fats that are primarily found in animal products. CLA has been called “the healthy trans fat” because some lab animal studies have shown that it may help reduce the risk of cancer, obesity and heart disease, and may improve immune function. The overall benefits and risks that CLA’s may pose to human health are not entirely clear.
Health Canada has recommended that the trans fat content of pre-packaged foods and food service menu items not exceed 5% of total fat content due to concerns that they may raise cholesterol levels and the risk of cardiovascular disease. However, fresh retail beef and other ruminant products are not included in this recommendation, primarily because trans-fats are naturally occurring in fresh beef and milk.
Omega-3’s
Omega-3’s are a family of at least nine different fatty acids. Omega-3’s are found in a very wide range of plant and animal products. Products containing omega-3’s can have a nutrient content claim, provided the product contains at least 300mg of omega-3 per serving (in Canada, one serving of beef is 75g).
Three members of the omega-3 family, ALA, DHA and EPA, have received particular attention. ALA is an essential fatty acid, meaning that it must come from the diet because the body cannot manufacture it. DHA and EPA can either come from the diet, or be manufactured in the body from ALA. DHA has a “biological role” claim in Canada due to its role in brain, eye and nerve development. EPA is believed to improve heart health.
ALA is far and away the most abundant omega-3 in beef, and very little of the ALA that a person consumes will be converted to either DHA or EPA. The levels of DHA and EPA are much higher in fish than beef.
Testing Feeding Strategies to Increase CLA and Omega-3’s Levels
Researchers have examined various feeding strategies to determine whether it’s possible to increase levels of CLA and omega-3’s in beef to consistently meet labeling requirements in a cost-effective manner without negative side-effects.
In monogastrics like humans, swine and poultry, fatty acids from the diet are absorbed as-is by the digestive system. If the diet contains more omega-3 or polyunsaturated fat, there will be more omega-3 or polyunsaturated fat in the animals’ meat or eggs. If the diet contains no trans fats, there will be no trans fat in the meat or eggs.
Modifying the fatty acid composition of meat is more difficult in cattle and other ruminants, because the rumen microbes first break down dietary fats and convert unsaturated fats (like omega-3’s and CLA’s) into saturated fats before the animal absorbs them. This challenge has led to considerable research interest in developing cost-effective feeding strategies to alter the fatty acid composition of beef.
Forage-finish
Studies have found that the fat from forage-finished beef contains considerably more CLA and omega-3 than grain-finished beef. However, the majority of Canadian consumers trim the external fat from a steak before eating it, leaving only the marbling fat. Forage-finished beef usually has less marbling fat than grain-finished beef. When CLA and omega-3 levels are calculated on a per-steak basis, the difference between forage- and grain-finished beef virtually vanishes for CLA, although omega-3 levels are still considerably higher in grass-fed than in grain-fed steaks.
Because a nutrient content claim for omega-3 requires at least 300mg per 75g serving of beef, the total omega-3 content of Canadian beef would have to increase by five to eight times to reach the levels required for a nutrient content claim. Under the Beef Science Cluster, National Check-Off funds are supporting a study led by Dr. Ira Mandell at the University of Guelph to identify breed and forage combinations that may increase CLA and omega-3 levels in beef. Results of this study will be available in Summer 2013.
Oilseeds
In addition to forage-finishing, another approach has been to feed sunflowers (for CLA) or flaxseed (for omega-3) to increase the dietary supply of the raw materials needed to manufacture these fatty acids in the rumen.
Rumen pH buffer
A third approach is based on the theory that rumen pH influences fatty acid levels in beef. Due to its lower starch content, dried distillers’ grains with solubles (DDGS) can act as a rumen pH buffer when used to replace grain in the finishing diet. A study led by Dr. Mike Dugan at the Lacombe Research Station received National Check-Off funds to examine whether adding a pH buffer (1.5% sodium sequicarbonate or distillers’ grains) to a barley-based diet would affect CLA or omega-3 levels.
Although there has been some progress, neither oilseeds nor buffers have successfully increased omega-3 levels enough to reach a nutrient content claim.
Fishmeal
A fourth approach has been to feed fishmeal to cattle. This has been more successful in increasing DHA and EPA omega-3 levels in beef, however, feeding even low amounts of fishmeal to cattle can adversely affect the flavour, colour and shelf life of beef. Much of the flavour of meat comes from the fat. A change in the fatty acid composition that negatively affects the eating quality of beef is unlikely to benefit either beef producers or consumers.
Although it has proven difficult to increase omega-3 levels in beef enough to achieve a nutrient content claim, this research has vastly increased our knowledge of the fatty acid composition of beef. This is very important to ensure that the industry has the information that is needed by consumers, food retailers, and regulators.
To learn more about research on this topic, visit the Functional Fatty Acids page on BeefResearch.ca.
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This is certainly an interesting article for those wishing to consume or produce beef with enhanced levels of ‘healthy’ fatty acids. It may also be of interest to note that the long chain omega-3 in beef with the highest concentration is DPA, and that in other parts of the world, beef is considered a significant source of long chain omega-3’s where people don’t eat a lot of fish. In addition, it would be worth mentioning that beef is a source of a ‘healthy’ trans fatty acid know as vaccenic acid, and this can in part be converted to rumenic acid (the main type of CLA). http://naturaltransfats.ca/
The question I tweeted out was in reference to the ecological footprint of the different feeding strategies IF they prove effective at impacting CLA and/or omega-3 levels. Current research on the carbon balance of the “conventional” feedlot setup would suggest that it has the lowest GHG emissions potential. I think the type of consumers interested in paying a premium for this type of product would also like to know the larger impacts of the production system it comes from. More of a “next steps” after this project is concluded.
Hi Craig. Thanks for explaining your question here.
There is some evidence that feeding oilseeds (like sunflowers or flax) can also reduce methane production, while forage finishing increases methane production. But forages are likely superior to annual crops when it comes to carbon sequestration. Which one has a better carbon footprint will depend on the relative balances between C production and sequestration. We are planning to support some research under the next Beef Science Cluster to evaluate how different cattle production practices (including diet) impact the environmental footprint (carbon, as well as other environmental goods and services provided by the forage and beef industry such as soil conservation, watershed maintenance, plant biodiversity, wildlife habitat, etc).
Excellent! That’s what I was hoping to hear. Sometimes too much focus on results in a vacuum, and not look at all of the other impacts.
Regarding Twitter questions asking if enough CLA & Omega-3’s in #beef for a nutrient content claim? Do alternative feeding strategies increase them? First, at present you can’t make a CLA or VA claim. Cases are being built to define their health benefits, amounts needed to attain benefits, and these will hopefully be used to petition regulatory authorities to allow for content or health claims. From a regulatory perspective, CLA’s and VA are where Omega-3’s were15-20 years ago. For omega-3’s, feeding flaxseed can increase omega-3’s in beef, but tough to get level for claim in lean beef. You can reach level for content claim in ground beef and further processed product. Feeding strategies can increase levels of these fatty acids in beef. To really good absolute increases in omega-3’s you have to protect the linolenic acid from hydrogenation, typically by protecting from lipolysis. To get large absolute increases in CLA and VA, you have to feed an oil/oilseed and keep polyunsaturated fatty acids from being completely hydrogenated. It seems feeding oilseeds in high forage diets for extended periods is one way to do it. I’ve actually seen >10% VA in perirenal adipose tissue!
Instead of focusing on one or two fatty acids i beef, I think our focus will eventually be on the complete fatty acid profile. Sure you have omega-3 and CLA, but there are a number of different omega-3’s and CLA’s. In addition, aside from CLA’s, there are a number of other biohydrogenation products and branched chain fatty acids with potential health benefits.
Agree with Mike Duggan. Taken holistically evidence shows we evolved from following and eventually domesticating the ruminant beasts, now represented.by modern cattle. The fats in these cattle fed high carotenoid, greens of the land contain all the healthy fats and nutrients in balance for our body, eyes and brain. This kind of predominately pasturage husbandry sequesters more carbon back to soil and provides food for thought with health benefits many times our current system. The evidence is becoming clear around the world. Sustainability lies again in such beef as the centre of the plate and ‘back to the future’ strengths in diversification. Remember all of the winter survival, health giving nutrients including not least vitamin D, are in the fat profile. In the last two + decades we have doubled our soil carbon in sinc. With the best world wide scientific trials and recently calculated that such a worldwide system would sequester as much Co2 equivalent as produced by half a billion cars( the worlds current estimated number) and produce more high quality meat than our current, unsustainable grain fattening system.