Past your eyes or Homogenise? - by Alexandra Hart

Digestive Health, September 07, 2016

Dairy products: what to watch out for and what to look for

Understanding Pasteurisation and Homogenisation

by Alexandra Hart, PhD, MNZAC

I was recently talking with Ben about dairy products: what to watch out for and what to look for. Ben mentioned the difference between pasteurisation and homogenisation. I'd never really though about either so I decided to start paying attention to the labelling and find out more. 

 

Pasteurisation is a process of heating milk up and then quickly cooling it down to eliminate certain bacteria. This also reduces the enzymes available to us when we drink it. It's intended to make milk 'safer' and government agencies claim it doesn't reduce its nutritional value. It can extend the shelf life of milk to up to 9 months in some cases. The most common methods of pasteurisation don't just kill harmful bacteria. They also kill good bacteria and mean that the milk is no longer a live food. Its very difficult to find milk in NZ that has been pasteurised at a temperature that leaves the good bugs alive. 

  

People argue about whether pasteurisation changes the nutritional value of the milk. It doesn't change its basic constituents so in theory it doesn't but I think this is a simplistic definition of 'nutritional value'. I've recently been experimenting with adding live foods (mainly yogurt) to my diet and I've been very surprised at how much better I feel for it. My digestion has improved, the food feels more satisfying and my overall nutrition has improved. I've decided to source raw milk and start making my own yogurt from that rather than pasteurised milk.

Setting 'bugs or no bugs' aside I think an equally important issue to look at is homogenisation. Homogenisation breaks down fat molecules in milk so that they don't separate out of the milk and rise to the top and form a layer of cream. The main reasons why milk manufacturers homogenise milk are so that they can mix milk from different herds, target consumers who don't find a creamy top attractive (they exist???) or want milk with lower fat percentages and to significantly increase the shelf life of the milk so that it can be more widely distributed. 
  

Should you be worried about any of that? To create these 'improvements' homogenisation reduces the size of the fat molecules in the milk and also rearranges the fat and protein molecules in ways that potentially have consequences. Some studies have shown that this significantly alters the way we digest milk. Consuming milk in which the fat and protein molecules have been rearranged and the fat molecules have been made smaller could increase your risk of heart disease, cancer, diabetes and allergies to milk. I say "could" here as the jury is still out. Studies have shown this to be the case but (mainly due to a lack of funding) these studies haven't been repeated to corroborate their results. An all too familiar story when the results of research do not support the interests of the food industry. Proving a direct relationship in such cases is very difficult as disease processes are complex and so is digestion.

I decided to take a practical approach. For the past two months I've avoided homogenised dairy products to see if it made any difference. I trust that my body is smart enough to give me feedback on what works and what doesn't. The result has been very interesting. My liver is functioning better, I don't get acne from dairy products anymore and I'm getting clear and accurate 'signals' from my body about when I want dairy and how much. I'm also more able to digest all dairy products. I always think that what our skin does is very telling because the skin in Ayurveda and Traditional Chinese Medicine is considered to be an extension of the digestive tract and the lungs. The state of the skin points towards the health of all the mucous membranes in the body. This is why if you react to something on your skin (eg. a kind of oil) you shouldn't eat it. My skin is telling me that non-homogenised dairy is ok. I've also noticed that this is the only winter I've had where I've been  free of excess mucous in my nose, throat and sinus. In sum, I'm breathing better, eating better and I have clearer skin. That works for me :-)
  

Of course, there is the question of sourcing the stuff. Non-homogenised milk is easy enough to get in the supermarket. It's labelled as such which helps. Non-homogenised cream is another story. Lewis Road Creamery's Single and Double Creams are pasteurised but not homogenised. They are not labelled as non-homogenised but I rang the factory and asked and they assured me that these products are not homogenised. Yay!

I've recently found a source of raw milk but not a source of raw cream so for now I'm using the raw milk to make yogurt and the Lewis Road Creamery cream.  If you know of a source of raw cream let me know! 
  
Best wishes,

Alex

contributed by Alexandra Hart, PhD, MNZAC

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