The Durk Pearson & Sandy Shaw®
Life Extension NewsTM
Volume 9 No.
2 • April 2006
When Pigs Have Fins: The New Health Snacks—Pork Skins and Bacon?
Pigs may never have fins, but there is already a new genetically modified pig strain that has been given a gene for a fatty acid desaturase that allows the pigs to make large amounts of n-3 fatty acids from n-6 fatty acids. They don’t look like fish and they don’t taste like fish, but you can get the same healthy EPA and DHA from eating them. As the new paper notes, one of the main reasons that livestock have such high levels of n-6 fatty acids in their tissues is because of the large amounts of grain they are fed to fatten them up. [Pasture-fed cattle, such as our own, have far less of these fats and get more of the n-3 alpha-linolenic acid from the fresh grasses they eat, resulting in a more desirable n-3/n-6 fatty acid ratio; however, because they do not have the fatty acid desaturase gene, no cattle (yet) can make the long-chain n-3 EPA and DHA. Actually, fish themselves do not have such a desaturase; they get their EPA and DHA entirely from their diet.]
The new and improved piglets have an n-6/n-3 ratio of 1.69 ± 0.30, as compared to the wild-type (without the added gene) piglets with an 8.52 ± 0.62 ratio. The transgenic animals’ production of EPA was increased by over 15 times, while DHA was increased by slightly less than twofold. Total n-3 fatty acids were increased to 8.59 ± 0.84%, as compared to 2.18 ± 0.25% in the wild-type piglets. Meanwhile, total body content of n-6 fatty acids was decreased in the transgenic piglets as compared to the wild-type, from 18.46 ± 1.41% to 14.28 ± 1.31%.
Normally, pork contains about 40% oleic acid, about 15% n-6 fatty acids, and only about 1% n-3 fatty acids. Some pig producers have increased n-3 fatty acids in their animals by feeding them an n-3 enriched diet, such as flaxseed (a good source of alpha-linolenic acid), fish oil, or fish meal. However, too much of the alpha-linolenic acid alone in pork results in a change in its sensory qualities, while EPA and DHA did not have these effects. Moreover, in the long run, having animals that can make their own n-3 fatty acids from n-6 fatty acids will be much more economical than having to feed them expensive fish oils or fish meal.
It will be interesting to see how long the FDA procrastinates on whether to allow humans to eat genetically engineered n-3-enriched pigs. Will they “protect” us from them by allowing only the much less healthful high-n-6 fatty acid, low-n-3 fatty acid pigs now in the marketplace? We love the taste of bacon but don’t like all the unhealthful fat it contains. It will be much more attractive as a food with a relatively high content of n-3 fatty acids. Now all they have to do is get rid of the excess saturated fats …
- Liangxue Lai et al. Generation of cloned transgenic pigs rich in omega-3 fatty acids. Nature Biotech 24(4):435-6 (2006).