It looks like we might have to start adding permeates to our milk again

Sigh. Picture: Getty Images

Back in 2012, “permeate-free” milk started showing up on supermarket shelves.

Milk producers nationwide rushed to ensure they could add the disclaimer to their cartons as shoppers quickly dove in for what looked like a “healthy” option.

Permeate is separated from milk by ultra-filtration and is also a by-product (not “waste product”) of cheese-making. In the pre-non-permeate days, monitoring its levels was a way of ensuring milk tasted the same all year round.

Milk flavours change as seasons change, and cows move between different pastures.

Here’s what Choice has to say about permeates:

“The Food Standards Code allows manufacturers to add or withdraw “milk components” to or from milk as long as the total fat level remains at least 3.2% (for full-cream milk) and the protein at least 3% (for any milk).

Manufacturers aren’t required to list permeate on the ingredients list. Permeate-free labelling appears to be a marketing move in response to concerns from some consumers about its use in milk, but there’s no evidence to suggest you should avoid it for nutritional or safety reasons.”

Now, prepare for permeates to make a comeback. A team from the University of California has found permeates are a good source of useful oligosaccharides, which are difficult to manufacture.

Oligosaccharides are carbohydrates which behave like prebiotics, and encourage the growth of a baby’s gut bacteria. That’s important, because the development of a baby’s gut bacteria has been found to have a significant effect on what other microbial species that follow can comfortably settle in for life.

Those species in turn have been found to influence a person’s chance of developing disorders from obesity to Parkinson’s disease.

A baby’s gut bacteria is about 90% B. Infantis, and the UC team found it thrives on oligosaccharides – found in human and, you guessed it, cow’s milk.

Now: guess which part of cow’s milk we’ve been throwing away that contains the “plenty of useful oligosaccharides”?