This article was first published in The Montreal Gazette.
The history of humans drinking cow’s milk is fascinating and not devoid of controversy.
Our ancestors were milking sheep, goats and cattle long before they were drinking milk. They weren’t drinking it because if they did, it would make them sick: diarrhea, cramps and bloated stomachs. That’s because after weaning, the mammalian gene that produces lactase, the enzyme that breaks down milk sugar lactose into the absorbable components of glucose and galactose, becomes inactive since milk is no longer consumed. Any lactose then ingested travels to the colon, where bacteria digest it and produce gases that cause the symptoms of “lactose intolerance.”
Why did they begin to domesticate animals for milk if they couldn’t drink it? Because they accidentally discovered that under certain conditions, milk turns into cheese, yogurt or kefir, all of which they were able to consume with no problem. They didn’t know this was because lactose-digesting enzymes had found their way into milk from bacteria or from the stomach of calves.
How is it that today we can drink milk without upsetting our digestive tract? Actually, not all of us can. About 70 per cent of East Asians cannot drink milk without experiencing adverse effects but only about five per cent of people of Northern European descent are lactose intolerant, thanks to a chance mutation in Europeans sometime between 3000-1500 BCE that prevented the lactase-producing gene from being switched off. Not only did this mean that milk could be safely consumed, it also provided a survival advantage. Milk is high in nutrients and was usually safer to drink than water, which was often contaminated with pathogenic bacteria.
“Usually” is a significant qualifier, because unrefrigerated raw milk sours easily as lactic acid-producing bacteria in the milk multiply. Raw milk has the chance of being contaminated with bacteria that cause tuberculosis, diphtheria, brucellosis and typhoid fever.
Nevertheless, by the mid-1800s, milk had developed a reputation as a nourishing food, especially for children. That led to some producers using various tricks to increase profits. Thinning milk with water was a simple ploy, with a little gelatin added to thicken the texture. Chalk dust or plaster of Paris were often used to whiten the thinned milk and pureed calf brains were added to fake the look of rich cream.
Since dairy farms were remote from cities, keeping fresh milk from souring without refrigeration was a big problem. One solution was to add formaldehyde, the chemical used by morticians to embalm bodies as a preservative. That prompted critics to rally against “embalmed milk.” There were also stories about worms in milk when one dairy thinned milk with stagnant water, and chilling accounts about residues of cow manure. One article reported that the citizens of Indianapolis were consuming more than 2,000 pounds of cow manure in milk every year.
New York City witnessed the notorious “swill milk scandal” when demand for milk increased, but bad roads, long distances and lack of refrigeration made delivery difficult. It was then that city distilleries learned that cows could be raised on the “mash” left over from whiskey production and began to house dairy cows near their establishments. These animals were nearly all diseased and sometimes had to be hoisted with ropes to stay upright for milking. Their “swill milk,” full of pus and bacteria, caused an epidemic of infant deaths.
The solution to the problem of contaminated milk was “pasteurization,” introduced in the 1890s. Although named after him, Louis Pasteur never applied his heat treatment process to milk. Pasteur had been interested in the spoilage of wine and discovered that heating to between 55 and 60 degrees Celsius killed spoilage microbes without ruining the flavour.
It was German agricultural chemist Franz von Soxlet who first suggested pasteurizing milk in 1886, and by 1890, New York philanthropist Nathan Straus had set up milk pasteurizing stations and was aggressively promoting the drinking of pasteurized milk. Although infant diarrheal deaths were quickly reduced, pasteurization also triggered resistance, with opponents claiming that “heated milk is dead milk” and “boiling milk destroys vitamins.”
This was nonsense. Milk is not alive and pasteurization does not involve boiling. Pasteurization, along with water disinfection and vaccination, is considered to be one of the most significant public health interventions in history. Curiously, there are people today who are suspicious of pasteurization and maintain that drinking raw milk is a better option in spite of overwhelming contradictory evidence.
Anti-dairy advocates promote the notion that milk is linked with prostate and breast cancer. There is a weak association between a slight increase in prostate cancer risk and high consumption of milk and calcium, but not when consumption is moderate. Any association with breast cancer is even weaker. On the other hand, claims by dairy promoters that bones will crumble if we do not consume three servings a day are not supported by epidemiological evidence. Populations that do not consume milk do not have more bone fractures.
Where anti-dairy activists are on firmer footing is with the argument that raising cattle is unfriendly to the environment in terms of greenhouse gas production, water use and antibiotic resistance. There may be at least a partial solution to these problems with the introduction of milk that is labeled “animal-free” or “lab-made.”
There are two distinct technologies available. In “precision fermentation,” genes that have been identified as coding for the production of milk protein in mammals can be constructed in the lab and inserted into the genome of yeast cells. When this genetically altered yeast is fed a sugar solution, it will grow in bioreactors and crank out specific milk proteins that can be combined with plant-based fats and carbohydrates to create “Remilk,” a complete milk product that is already being used in ice cream, yogurt and cream cheese. It is free of lactose, cholesterol and hormones. A fluid milk product, called “New Milk” is set to be launched in Israel in January,
A second method involves the large-scale culturing of cow mammary cells in bioreactors to produce milk that is identical to conventional milk. It truly is, because it is made by the same cells that produce milk in a cow. There are technical details to work out, but “UnReal Milk,” as it will be called, may be appearing on shelves in 2026. Needless to say, there is controversy. Dairy producers argue that these products should not be called “milk” because they are not produced by a cow, and activists, in true form, are likely to raise fear about “Frankenmilk.” As for me, I wouldn’t mind sporting an UnReal milk mustache.
