With the conversation about raw milk heating up recently (no pun intended), and more legislation being introduced to allow it to be sold at the state and local level, we’ve been wondering about the history of pasteurization and why it became legislated in the first place. Sometimes the reasons we do things get lost once a problem is solved; subsequent generations forget about or are unaware of the problem that led to the solution in the first place. So, to add to the discussion, here’s why we pasteurize milk:
Tuberculosis, Typhoid, Diphtheria, Brucellosis, Cholera Infantum and more….
There is some evidence indicating that human populations began to increase about the same time we domesticated goats, sheep and cattle and then began drinking their milk. So, in a very real sense, milk has made us what we are today. But milk hasn’t always been life-giving. About 150 years ago, we discovered that illnesses are caused by microorganisms or germs. And about that same time, we discovered that some of the deadliest diseases humans faced were a result of drinking milk that contained these microorganisms.
In 1882, German scientist Rupert Koch discovered that bovine tuberculosis could be spread to humans via milk. By 1907, milk containing the pathogens for tuberculosis, typhoid and diphtheria had been linked to the deaths of hundreds of New York City’s children annually. But it was the typhoid epidemic of 1913 that killed thousands of people that finally resulted in action. Public health officials knew that typhoid fever was carried in milk, and that pasteurization could make milk safe to drink so by 1914, 95% of the city’s milk supply was pasteurized. The impact was tremendous. Infant mortality rates dropped from 27% to 9%.
Change Takes a Long Time
Nathan Straus, founder of Macy’s, lost his own son to milk-caused diphtheria in the late 1800s and campaigned for pasteurization for decades. He set up “Milk Depots” offering pasteurized milk on the spot at affordable prices, along with free medical exams for children and hygiene advice for mothers. He started providing pasteurized milk to a local orphanage with a death rate of 42% from tuberculosis and other milk borne diseases. Within a year the death rate dropped to 28% and continued downward in subsequent years.
But in spite of his efforts and those of many like him, in 1938 U.S. public health officials estimated that a quarter of all food-borne illnesses were linked to unpasteurized milk. Over half of the milk in the U.S. was still sold raw. In 1943, Edsel Ford, the 49 year old son of Henry Ford died of undulant fever (Brucellosis) brought on by drinking unpasteurized milk from one of the family farms. The swing to nationwide pasteurization began as World War II ended as states began requiring pasteurization of milk and the federal government banned the interstate sale of raw milk.
Listeria, E. Coli and Campylobacter
Safer, cleaner handling facilities in dairies have also contributed to reduction in milk-borne diseases. But no matter how clean you are, it’s hard to get rid of bacteria that just naturally exist in even healthy animals, like Listeria, E. coli, and Campylobacter. The symptoms of infection for each of these bacteria are similar and include diarrhea (sometimes with blood) vomiting, fever and headaches. Each of them can result in serious or fatal infections in children, the elderly, and anyone with a compromised immune system.
It can be worse though. Listeria can cause miscarriages and still-born births in pregnant women. E. coli can cause complete kidney failure and this outcome has been documented in a number of recent cases. In one, a 23 month-old little girl suffered a stroke, and underwent transplant surgery to receive one of her mother’s kidneys. At the age of 3 she takes all her food through a feeding tube, cannot walk or talk and goes to physical and speech therapy five times a week.
Public health officials are especially concerned about Campylobacter which is the fastest-growing cause of raw milk related illnesses. In two recent cases campylobacter infections have have triggered Guillain-Barré syndrome in the victims resulting in paralysis.
Pasteurization kills bacteria and diseases, and increases milk’s shelf-life.
There are two levels of pasteurization. The most common in the U.S. is High-Temperature, Short-Time, where milk is forced between metal plates or through pipes heated on the outside by hot water to 161 degrees F for 15 seconds. This kills 99.999% of the viable microorganisms in milk. Because many of the bacteria that could cause spoilage are killed by pasteurization, HTST milk’s shelf life is longer, lasting about 2 to 3 weeks once its packaged. Ultra-High Temperature pasteurization holds the milk at 280 degrees F for 2 seconds. When combined with sterile handling and containers UHT milk can be stored unrefrigerated for 6 to 9 months. This type of pasteurization is particularly popular in Europe because of the high cost of transporting milk in refrigerated trucks.
Should People Have a Choice?
People can choose to smoke, to drink alcoholic beverages, and in some states to partake of marijuana. Most of us have received the education that describes the health consequences of those items so that we can make informed choices. Perhaps the same should be said for raw milk.