Making American milk safe

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In 1887, a New Jersey toddler called John Summerfield Coit died of milk-borne diphtheria. Neither his death at such a young age nor that he contracted the disease that killed him from drinking cow’s milk was unusual. In 1880, 28.8 percent of babies in nearby New York died before their first birthday. The primary cause of this extreme infant mortality rate was infectious diseases, with milk acting as a major vector of transmission. Raw cow’s milk can carry pathogens including typhoid, diphtheria, scarlet fever, and tuberculosis. All of these were significant killers of children and adults in nineteenth-century America.

Raw milk was a particular threat to infants because it was common for babies to be fed partly or exclusively on cow’s milk, an ancient practice known as ‘artificial feeding’ that grew in popularity as bottle designs improved and more mothers worked outside the home. As populations urbanized, artificial feeding became more dangerous because milk had to travel further distances. The widespread practice of adulteration increased the risk to babies. The result was very high infant mortalitywhere breastfeeding rates were lower, caused by gastrointestinal diseases and pathogens.

One early twentieth-century study from New York’s Bureau of Child Hygiene found that of 1,065 infant children killed by diarrheal diseases, only 16.7 percent were breastfed exclusively, with 22.7 percent fed on a mixture of dairy and breast milk, and 60.6 percent exclusively artificially fed.

Today, widespread pasteurization has made milk safe. Pasteurization, a low temperature heat treatment, was invented by French chemist Louis Pasteur in the early 1860s. But 20 years later, John Summerfield Coit and his peers were still dying of milk-borne pathogens.

Delays in understanding that milk was a vector for disease, debates over the health effects of heat-treating milk, and confusion over effective pasteurization meant it took decades for milk pasteurization to become standard in the US, at a cost of hundreds of thousands of lives.

A contributor to this delay was the origin of Pasteur’s experiments. Pasteur began his work after being called on by Emperor Napoleon III to save the French wine industry because mysterious ‘wine diseases’ were rendering its output undrinkable. Pasteur himself never experimented with pasteurizing milk.

Furthermore, germ theory was in its infancy in the 1860s. Instead, it was the impurity of milk due to adulteration, not pathogens, that was the focus of American health authorities as the crucial factor in making milk dangerous to children. New York was the scene of history’s most notorious case of urban milk adulteration scandal: the 1858 Swill Milk Scandal.

Newspaperman Frank Leslie discovered that many of New York’s distilleries had acquired dairy cows. These distillery-dairies kept their cows in cramped, diseased conditions and fed them ‘swill’, the boiling alcoholic mash left over from making whisky. The distillery-dairies sold the milk produced by these sickly, ulcerated animals as ‘pure country milk’, after first improving its appearance with additives including plaster of Paris and starch. Leslie published a lengthy exposé, complete with illustrations showing the conditions inside the distillery-dairies and maps pinpointing their location.

Image source: Library of Congress.

A step forward in identifying the presence of pathogens in milk came in 1882, when German microbiologist Robert Koch discovered the human tuberculosis bacillus, which he named Mycobacterium tuberculosis. Koch achieved this by using a special staining method that made the bacillus visible under a microscope.

The staining method worked by smearing infected specimens onto a glass slide, using heat to fix the specimen to the glass, and then dipping the slide into an alkaline solution of methylene blue, followed by a dip into brown dye. After rinsing with water, this process revealed Mycobacterium tuberculosis, dyed blue on a background of brown because the alkaline methylene blue was able to penetrate the waxy coating of mycolic acid that surrounds TB bacilli.

He then injected the bacilli into guinea pigs and saw that they went on to develop the symptoms of tuberculosis. The discovery made Koch famous. But Koch did not identify bovine tuberculosis, believing that human and bovine tuberculosis were the same disease and doubting the extent to which tuberculosis could pass from cows to humans.

Serious interest in pasteurizing milk did not arise until the late 1890s, when a doctor and microbiologist working for the American government, called Theobald Smith, showed that bovine tuberculosis was a distinct, though related, pathogen from human tuberculosis. Smith published a paper warning that humans could be catching bovine tuberculosis from milk. Building on Koch’s seminal microbiology work, scientists and physicians identified more and more pathogens that could be caught from milk, which by 1900, included diphtheria, scarlet fever and typhoid.

But even once it was established that milk could carry dangerous diseases, there was resistance to its widespread pasteurization. In the US, take-up faced strong medical opposition from doctors, particularly pediatricians, who argued that the heating process might be making milk less nutritious and that clean, raw milk was best for infants.

Henry L Coit. Image source: Wikimedia Commons.

Notable among the medical men who resisted pasteurization was Dr Henry L Coit of Newark, father of John Summerfield. As a young man, Coit decided to become a doctor when he fainted upon seeing blood at the scene of an accident. After being told by a bystander that he would ‘never make a doctor’, he resolved to do just that, studying in his spare time and graduating aged 29 in 1883.

The death of his young son made safe milk a driving issue for Coit. Unimpressed by years of government inaction, in 1893 Coit wrote to his brother and sister of his ambition to change the dairy industry so that ‘the poorest baby in Coomes Alley will now fare equally well with Thomas Edison’s baby in Lewellen Park.’

Coit believed that the key factors in getting safe milk to children were the cleanliness of dairies, the health of the cows, the quality of the fodder that was fed to them, and the proper cold storage and transportation of milk. He created the Certified Milk Commission, a group of doctors working purely on a voluntary basis to regularly visit dairies and certify them as producing safe milk.

But Coit, like many pediatricians of his day, completely dismissed pasteurization, believing it to be a dangerous red herring. He called pasteurization a ‘compromise for pure milk’ and a way of making ‘dirty milk clean’. The resistance of medical men like Coit contributed to public skepticism towards pasteurization and also made dairies less likely to take up the process. Pasteurization was also somewhat counterintuitive. In this era, the safest milk was procured quickly, with as little time as possible between cow and cup. Many people believed that adding extra steps only increased the risk while worsening the taste.

Even as new research showed small children consuming pasteurized milk had lower rates of diarrhea and death, change was slow. Between 1890 and 1927, over 30 scientific reports were published that each recommended different temperatures and lengths of time necessary for pasteurization to kill tuberculosis. Meanwhile, milk producers were sensitive to anything that might give their product a ‘cooked’ flavor.

However, others became convinced that pasteurization was the key to providing the children of America with safe milk. Key among them was philanthropist and department store magnate Nathan Straus. Straus was born in what is now Germany in 1848, arriving in the US with his family as a 6 year old. First settling in Georgia, the Straus family moved to New York after the Civil War. Straus went into business selling crockery with his brother Isidor, who later died on the Titanic, and together they became partners in and then co-owners of Macy’s.

Image source: Jewish Virtual Library.

Like Coit, Straus’s motivations in joining the fight for safer milk were personal: two of his children had died from milk-borne tuberculosis. But unlike Coit, the tragedy turned Straus into a champion for pasteurization.

Straus’s great project was to familiarize Americans with pasteurized milk by making it widely available to them at loss-making prices, putting to bed fears that it was an inferior product through easy access and familiarity. Inspired by a New York paediatrician who had established a heat-treated milk dispensary for children, Straus began opening up his own milk depots in 1893.

In sharp contrast with Coit’s expensive certified milk, produced only by select dairies, Straus’s subsidized depots sold bottles of pasteurized milk cheaply and gave them away for free to poor families. An 1894 New York Times article describes one of Straus’s depots in City Hall Park, where a sign in English, Russian, Hebrew, and Italian advertised pasteurized milk for a cent a glass:

‘Across the park a peripatetic dairy vends buttermilk at 3 cents, but the lactivora of the town…descend with thirst unappeasable upon the pavilion of Mr Straus. There so long as the milky tide serves (it runs dry, alas! twice a day) may be seen the odd spectacle…of men and women and girls and boys elbowing and shoving each other for their cent’s worth of ice-cold milk.’

In 1900, Straus’s depots distributed over half a million bottles of milk, and by 1920, Straus had established 297 milk depots in 36 different American cities.

Nathan Straus’s First Milk Depot. Image source: Village preservation.

Straus and Coit knew of and disliked one another. When tuberculosis was discovered in one of Coit’s certified partner dairies, Straus described Coit in a private letter as ‘thoroughly discredited’. For his part, Coit privately wrote that he thought Straus ‘selfish’ and self-obsessed.

In 1907, President Theodore Roosevelt ordered the US Public Health Service to investigate the benefits of pasteurized milk. The resulting report was a victory for pasteurization. Surgeon General Walter Wyman wrote that it ‘prevents much sickness and saves many lives.’ In the wake of the report, American cities’ take up of pasteurization gathered pace. By 1924, every city with a population over half a million was pasteurizing at least half its milk supply. And on his home turf at least, Straus’s victory over Coit and his Certified Milk became absolute in 1910, when it became illegal to sell unpasteurized milk in New York, an ordinance that began to be enforced in 1914.

By 1923, New York’s infant mortality rate had decreased from 28.8 percent in 1880 to 6.6 percent. Alongside other improvements, such as better sanitation, the widespread pasteurization of the city’s milk was a contributor to that happy decline.

For Coit’s part, he was undoubtedly successful in getting safer raw milk to more people, and his emphasis on refrigeration and hygiene is mirrored in many of today’s practices. But he remained essentially blind to the value of pasteurization. Even after the US Public Health Service’s 1908 report set the tone for city health authorities across America by firmly recommending national take up of pasteurization, Coit described it in 1915 as a ‘temporary expedient’ until a better way of protecting the public from unsafe milk could be found. In the end, though both Coit and Straus shared a similar goal, and both were motivated by similar personal tragedies, it is Straus whose work has ultimately saved the most lives.

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Phoebe Arslanagic-Little is co-founder of Boom and a fellow at the Center for British Progress.