When I moved to China eight years ago, I was quite shocked at seeing milk in small boxes piled high on store shelves — at room temperature! With expiration dates longer than six months! How could this be safe — and nutritious? Like most other Americans, our milk was bought and sold at refrigerator temperatures, and kept fresh only for a week or so.
One of the greatest public health advances in the modern world is pasteurization. All milk must be sterilized after being delivered from the cow (or sheep or goat), mostly to kill dangerous bacteria and spores that otherwise can seriously harm and even kill people. To kill the pathogens, milk is exposed to high heat at specific lengths of time — this is called pasteurization, named after the famous 19th century French scientist Louis Pasteur. Heating not only kills pathogens but also slows down spoilage, which is triggered by other sets of bacteria.
Pasteur’s heating technique doesn’t kill all bacteria, which is why it must be kept cool and used within a couple of days after opening. Normal pasteurization heats milk to around 70 – 75 °C for 15 seconds, — but the newer technique heats at up to 150 °C for 5 seconds. This is why it is called ultra-high temperature (“UHT”) milk, which is what you see written on these cartons. At such a temperature, all harmful pathogens, including spores, are killed, as well as the enzymes which could spoil the milk, which is why you can keep at room temperature for months. The milk also goes directly into the container after heating, which eliminates possible contamination.
But what about nutrition — surely this higher temperature must destroy vitamins and other molecules? While there are some very minor changes, all of the major governmental and nutritional sites I’ve seen, including the US CDC; the European Union; and New Zealand all state the same essential facts, summed up by the US CDC: “all of the nutritional benefits of drinking milk are available from pasteurized milk without the risk of disease that comes with drinking raw milk.” And while I’ve read reports that milk’s enzymes are damaged even more with UHT processing, as the US CDC again summarizes, “the enzymes in raw animal milk are not thought to be important in human health.”
Most Europeans will find my initial hesitancy of UHT milk quite amusing, as it’s become the popular choice in most EU countries for many years. In China, almost all milk in stores is still the traditional pasteurized milk sold from the chilled containers, with UHT mostly still only available as imported brands in expat and upscale supermarkets. Fortunately, this UHT milk is now easily available on all major shopping websites for home delivery anywhere in China.
I have many patients and online readers, both expat and local Chinese, who are desperate to find quality milk sources ever since the melamine scandal of 2008 — especially for their children. My response to all is that UHT milk is a great choice — especially imported, and why not get organic as well! Such milk certainly is a far better choice for toddlers than toddler formula, which has no medical indication from any pediatric groups anywhere for its preference over milk.
I drink imported organic UHT milk mostly as a food safety precaution, but I also feel very reassured that my toddler son and family are all drinking milk 100% free of pesticides, heavy metals and growth hormones, from cows fed on grass in healthy organic farms. Given all the constant uncertainly here with food safety scandals, why not have some peace of mind with your milk?