Beef cattle and fish oil a healthy concoction

By STEVE CONNOR

It sounds like a culinary catastrophe, but scientists say it may soon be possible to breed beef cattle whose meat is enriched with the healthy properties of fish oil.

The researchers have shown for the first time they can create genetically modified mammals that secrete the omega-3 constituent of fish oil in their muscles.

Although the work has so far been carried out only on laboratory mice, the Harvard University scientists believe it is just a matter of time before a similar attempt is made on farm livestock.

Jing Kang, the leader of the research team from Harvard and the Massachusetts General Hospital in Boston, said mammals could not normally make their own omega-3 fatty acid, which is found in abundance in fish oil and is known to prevent heart disease and furred arteries.

But when the scientists inserted a gene into mouse embryos for an enzyme that can help to synthesise omega-3, they found abundant amounts of omega-3 in muscle tissues and relatively low amounts of the less beneficial omega-6 fatty acid - which the enzyme converts into omega-3.

"Our discovery indicates that this technology might be adapted to enrich n-3 fatty acids [omega-3] in animal products such as meat, milk and eggs," the researchers wrote in the journal Nature.

"The obvious follow-up to our finding would be to create livestock animals transgenic for fat-1 and see if their tissues also contain omega-3s," Dr Kang said.

Some domestic livestock, such as laying hens, are already fed a diet rich in fish oils in the hope of boosting levels of omega-3 in farm products.

But the scientists believe a GM alternative could be more effective.

"Correction of the usually omega-3-deficient Western diet has become a key step towards reducing the risk of several modern diseases," Dr Kang said.

"The current approach is increasing omega-3s in animal food products is to feed livestock with fish meal or other marine products, which is time consuming, costly and limited by the availability of those feeds."

Peter Melchett, policy director of the Soil Association which certifies organic farmers, dismissed the idea that the research would lead to GM farm livestock that would benefit human health.

"There is a widespread view that GM farm animals are going to be even less acceptable to the public than GM crops. There's going to be revulsion and outcry at the possibility of GM farm animals."

What is omega-3?

* Fatty acids found in fish and other marine sources, such as algae, are polyunsaturated fats or "good" fats, as opposed to saturated fats which increase the risk of heart disease.

* Fish oils may also be useful in treating a host of conditions including bipolar (manic-depressive) disorder, kidney stones, chronic fatigue syndrome and cystic fibrosis.

* Doctors suggest that people should eat two or three servings of oily fish such as mackerel or salmon each week because of the health benefits.

- INDEPENDENT