Nanogirl Michelle Dickinson: Fancy some low-fat bacon?

You could soon be tucking into bacon from pigs with 24 per cent less body fat than normal pigs. Photo / 123RF

Bacon. It's one of those foods that many people have a love-hate relationship with. The love comes from its delicious, salty crunchiness that partners so perfectly with soft buttered bread; the hate comes from dietary advice which says the fatty, processed meat might be harming our health.

With 68 per cent of bacon's calories coming from fat and almost half of those from saturated fat, bacon is seen more as a treat food than an everyday staple.

Nutritional advice has changed over the years, but the current recommendation from the New Zealand Nutrition Taskforce is that saturated fatty acids and trans fatty acids should make up no more than 12 per cent of our diet. This advice clearly puts bacon in the category of a sometimes food.

The future of bacon as we know it may be about to be disrupted with a scientific discovery which reduces the amount of fat in pigs thanks to a technique called CRISPR.

Pronounced crisper, CRISPR stands for Clustered Regularly Interspaced Short Palindromic Repeats and is a relatively new genome editing tool that allows scientists to edit DNA with incredible precision, efficiency and flexibility.

This week research published in the journal PNAS showed how researchers in China were able to produce genetically modified pigs which had 24 per cent less body fat than normal pigs while still being healthy and normal in all other ways.

The scientists achieved this by targeting a gene called UCP1 which is naturally lacking in the pig species, thought to be lost through evolution when pigs were mainly in the warm climate of the tropics.

The UCP1 gene is common in most other mammals and helps them to regulate their body temperature in cold environments. With this lacking gene, pig breeders have to ensure that enough heat is produced to keep piglets warm when they are young, especially during the colder months.

This additional heat adds expense and energy consumption to the pig breeder and is eventually passed on to the consumer.

The scientists took a mouse version of the UCP1 gene and used CRISPR to add it to edited pig embryos which were then transplanted into surrogate pigs.

In the study, 12 healthy piglets were produced which were much better at maintaining their body temperature by using energy from burning their body fat. With this new genetic code, the animals were able to keep warm naturally which increased the piglet survival rate and caused the piglet to lose fat, resulting in a leaner pig.

Even if low-fat bacon doesn't sound appealing to you, this fast pace of innovation brings a new era of genetically modified foods with some interesting ethical questions.

Right now the US Department of Agriculture doesn't regulate CRISPR-developed foods because, although they are genetically engineered, no foreign genetic material is introduced in the process. The difference is that rather than adding genetic materials from another species, CRISPR changes the way that genes are expressed within a species. This makes it easy to "turn off" genes one at a time to see what each of them does.

To date, CRISPR has been used to create drought-resistant maize, hornless cattle and even more muscular police dogs. The technique can also be used to remove genetic disorders in human embryos, kill antibiotic-resistant bacteria and target the control centre of cancer cells.

The researchers in this study did not go out looking to produce low-fat bacon, however, they accidentally discovered that CRISPR can not only change the food that we eat, but also reduce the cost of farming. The question is, are we as consumers ready to accept this new genetically edited food?