Omega-3 fatty acids are considered to be “healthy” fats. Found mainly in fish, these fats have been linked to beneficial cardiovascular effects and other health benefits, such as a decreased risk of cancer and diabetes and a positive effect on inflammatory disorders. However, most farm animals eat grains and other plants that contain omega-6 fatty acids, which are not processed by the body the same way as omega-3 oils and do not offer the same health benefits. Some studies have even linked a higher omega-6 to omega-3 ratio to a higher prevalence of disease, particularly coronary artery disease. This makes many meats, especially farm animals, a less healthy source of fats in the human diet. A transgenic solution has been attempted to increase human consumption of omega-3 fatty acids by converting the dietary fat already being consumed (NewScientist).
The effect of omega-3 (or n-3) fatty acids on health can be studied in a mouse model. Jing Kang at Harvard Medical School published the details of the development of the model in 2007 in the journal Prostaglandins, Leukotrienes, and Essential Fatty Acids (read the study here). The fat-1 gene from C. elegans (a type of unsegmented worm commonly used in research) was integrated in to the mouse genome in a manner that allows the mice to convert omega-6 fatty acids into omega-3 fatty acids, and the health of these mice can be directly compared to non-transgenic mice on the same diet. In 2006, the journal Nature Biotechnology published a study demonstrating the practical use of this approach in the food supply (read the study and press release here): the same research group at Harvard Medical School created piglets that express a slightly altered, or humanized, version of the gene by inserting it into the piglet genome using established genetic engineering methods.
Armed with the protein this gene encodes, n-3 fatty acid desaturase, the transgenic pigs are capable of converting the omega-6 fatty acids from their diets into omega-3 fatty acids. The converted fatty acids are then incorporated into the fat stores on the pig. This fat with higher omega-3 content can then be consumed by humans. The pork is still pork, and bacon is still bacon – but the fat content is healthier without any dietary changes for the pigs.
This same gene and genetic engineering technique is also being used in chicken, increasing the potential for fat-friendly meat on the market. In addition to fat-friendly meat, the Harvard researchers led by Kang have been integrating omega-3 fatty acids into fruits and vegetables that normally do not contain them, such as tomatoes. The transgenic foods may even have a more pleasant taste or aroma based on more recent studies. However, none of these fat-friendly, omega-3 transgenic foods have yet been approved for human consumption or commercial use.