Beef with "healthy" fat

Genetically modified cattle should produce more omega-3 fatty acids

Beef contains very little polyunsaturated fatty acids and therefore does not have a particularly healthy reputation. © freeimages
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Meat as well as fish: Thanks to an additional gene, cattle are supposed to produce a higher proportion of "good" fat that is usually found in fish. Chinese scientists have increased the amount of polyunsaturated fatty acids in beef more than fivefold. However, the new cattle are far from mature.

Common diseases such as obesity and diabetes are on the rise in the industrialized countries - one of the causes is a high-fat diet. However, the long-chain and polyunsaturated omega-3 fatty acids are often considered the "good" fat: If the diet contains a higher proportion of these fatty acids, this can prevent heart disease, obesity and neurodegenerative diseases.

Especially rich in omega-3 fatty acids are vegetable oils, but also the fat of sea fish such as herring, salmon or anchovy. Beef or pork, on the other hand, contains mainly unhealthy saturated fatty acids. By feeding the animals with fishmeal, the amount of omega-3 fatty acids can also be increased in cattle, but so far only with moderate success.

Five times as much "good" fat

Scientists around Linsen Zan from Northwest A & F University in Yangling, China, want to go another way: Cattle are supposed to self-assimilate the unsaturated fatty acids themselves. To do this they inject a gene called fat1 into fetal cells of the Luxi yellow cattle, a high-yield Chinese cattle breed. The gene encodes an enzyme that plays a major role in the conversion of polyunsaturated fatty acids.

The result: The introduction of the fat1 gene increased the proportion of "good" fats in the cattle by more than five times. "For the first time, we've been able to show that it's possible to breed a new nutritionally better breed of cattle in terms of the composition of their fatty acids, " says Zan. Similar genes have already been introduced by international research groups in pigs, dairy cattle and sheep. display

"Still much to learn"

However, so far it has remained with this proof that the method works in general the new breed is not yet ripe: Of 14 cowboys who received the fat1 gene, 11 died within the first four months. The cause of death was mainly in cattle spread infections and inflammation. Why the animals are apparently more susceptible to these diseases is still unclear. Incomplete reprogramming of the cells or erroneous regulation of the genes as the embryos develop may be possible.

"There is still much to learn in terms of the best scientific and agricultural methods to get a nutritionally valuable beef with high levels of omega-3 fatty acids, " said first author Gong Cheng of Northwest A & F University. "But the beginning has been made." The scientists are convinced that with the help of their study, they will get a bit closer to sweeter beef in the future. (Biotechnology Letters, 2015; doi: 10.1007 / s10529-015-1827-z)

(Springer Link / Biotechnology Letters, Cheng et al., May 11, 2015 - AKR)