Putting milk permeate in perspective – by guest expert Glenn Cardwell APD

When my mother-in-law arrived on the weekend with a paella pan for my birthday and some hard hitting questions about milk, I could feel the next blog post coming on.  No, not a Spanish recipe.  Be patient.  Recipe Redux comes next week.  But rather clear and sensible answers to her questions about a staple product she’s been drinking for 75 years.  Should she now buy permeate-free milk? Is it really better?  To sort out if the grass is really greener we asked one of the most experienced and respected Australian dietitians for his expert opinion. 

About our expert: Glenn Cardwell has 33 years experience in clinical and public health nutrition, including 10 years as consultant dietitian to the National Heart Foundation.  He was one of the original sports dietitians to establish Sports Dietitians Australia in 1996. Glenn has written four books, Diet Addiction, Gold Medal Nutrition (five editions), Getting Your Kids to Eat Well and the Top Blokes Food Manual.

Very recently we learned that humans in sub-Saharan Africa were drinking milk around 7000 years ago through clever analysis of pottery found at an archaeological site ¹. In other parts of Africa, through the Arab nations, east to India north throughout Europe, humans have relied on milk as a food source for at least 5000 years. That means we have been enjoying milk for its nutritional benefits long before tea and coffee helped wake us up in the morning.

Milk market

Nowadays there are all types of milk on the market, from low-fat to vitamin and mineral fortified. When PURA, the makers of the milk I have on my cereal, asked me to comment on permeate-free milk, I realised very few people had heard of permeate. I was unsure myself. So let’s take a look at together.

Milk is a nutritious fluid composed of protein, fat, carbohydrate (lactose in this case), vitamin and minerals. When milk is processed to make cheese, the protein and fat are used, and in making yogurt most of the protein, fat and lactose is used. In both cases, the processing leaves a fluid with some lactose, minerals and vitamins. This fluid is called permeate. What milk suppliers can do is add this permeate back to milk. Why? Because the composition of milk naturally fluctuates depending upon the season, breed of cow and the type of feed given to the cow. Adding permeate allows the milk to be standardised for its protein content, so milk composition doesn’t change throughout the year.

Purity push

As you can see, there is nothing wrong with permeate. It’s natural and perfectly safe to add back to milk. When the manufacturers Dairy Farmers and PURA asked consumers about milk, they were told that they preferred milk as close as possible to how the cow made it and they would be happier if the permeate was left out, even though it was legal and safe ^2,3,4 . Some people see adding permeate as “diluting” milk. The manufacturers decided that from July 2012 they would be changing to permeate-free milk. Dairy Farmers in NSW and Queensland and PURA milk in WA, SA, Victoria and Tasmania. If you live in WA then you have had permeate-free milk from PURA since January 2012 (although it was not mentioned on the label until July).

If you are unable to view this video please jump back to the blog to see it.

My perspective

So what do you really need to know? First, be aware that milk was always a great drink and a wonderful source of protein, calcium and riboflavin. The permeate was added just to make milk standardised throughout the year. Now, with permeate-free milk there will be a natural seasonal variation in the protein content of milk, although this variation will not be large (between 3.0 – 3.5 g per 100mL) and it is very unlikely that you will be able to taste the difference. Not adding permeate makes milk manufacturing easier and closer to what you get from the farm.

References
¹ Dunne J et al. Nature 2012; 486: 390-394; ² Online survey conducted by TNS from 27-29^th April 2012 amongst 1346 Australians aged 16-64 years; ³ Hartman Group – Looking Ahead. Food Culture 2012 Pages 13, 29, 53; ⁴ Innova Market Insights – Top Ten Trends in Food for 2012.

Editor’s comment:

Thanks Glenn it’s so wonderful to have you on Scoop.  I certainly have heard a lot of fuss about permeate lately and when a 75 year old asks questions, you know it’s hit mainstream.  Some people I talk to are skeptical about the marketing motives behind the change.  I am one of those consumers blissfully unaware that I was even drinking the stuff? And I’ve heard others say permeate is safe and the change makes no difference to the health properties of milk. But at the end of the long milking line, whether a clever marketing manager came up with idea in his big city office, or not, it did grow from a fresh approach.   And that’s from a growing movement of people demanding a cleaner, minimally processed food supply.  If we can still bring nutritious milk to the masses in a purer way, I’m all for it.  How about you lovely readers?