Medical News

Milk Has Lost Its Magic

Milk is defined by its percentages: nonfat, 2 percent, whole. Now there is a different kind of milk percentage to keep in mind. Last week, the FDA reported that 20 percent of the milk it had sampled from retailers across the country contained fragments of bird flu, raising concerns that the virus, which is spreading among animals, might be on its way to sickening humans too. The agency reassured the public that milk is still safe to drink because the pasteurization process inactivates the bird-flu virus. Still, the mere association with bird flu has left some people uneasy and led others to avoid milk altogether.

That is, if they weren’t already avoiding it. Milk can’t seem to catch a break: For more than 70 years, consumption of the white liquid has steadily declined. It is no longer a staple of balanced breakfasts and bedtime routines, and milk alternatives offer the same creaminess in a latte or an iced coffee as the original stuff does. Milk was once seen as so integral to health that Americans viewed it as “almost sacred,” but much of that mythos is gone, Melanie Dupuis, an environmental-studies professor at Pace University and the author of Nature’s Perfect Food, a history of milk, told me. In 2022, the previous time the Department of Agriculture measured average milk consumption, it had reached an all-time low of 15 gallons a person.

If concerns around bird flu persist, milk’s relevance may continue to slide. Even the slightest bit of consumer apprehension could cause already-struggling dairy farms to shut down. “An additional contributing factor really doesn’t bode well,” Leonard Polzin, a dairy expert at the University of Wisconsin at Madison’s Division of Extension, told me. For the rest of us, there is now yet another reason to avoid milk—and even less left to the belief that milk is special.

The risks of bird flu in milk can be simplified to this: Thank God for pasteurization. Straight from the udder, in its raw form, milk is “a substance that’s very much open to contamination if not managed well,” Dupuis said. Milk is like a petri dish of microorganisms, and before pasteurization became the norm, milk regularly caused deadly diseases such as tuberculosis, scarlet fever, and typhoid fever. The pasteurization process, which involves blasting milk with high temperatures and then rapidly cooling it, is “intended to kill just about anything a cow could have,” Meghan Schaeffer, an epidemiologist and a bird-flu expert who now works at the analytics firm SAS, told me.

That includes the bird flu. Yesterday, the FDA reported new results from ongoing studies reaffirming that the bird-flu fragments it found in milk and other dairy products aren’t active, meaning they can’t spread disease. The agency confirmed this using a gold-standard test that involved injecting samples into chicken eggs to see if any active virus would grow. None was detected afterward. “That process really saves us,” Schaeffer said.

There is never a good time to drink unpasteurized milk, but now is an especially bad one. A number of states have legalized the sale of raw milk in recent years, part of a right-wing embrace of the beverage. Raw milk from sick cows contains bird-flu virus in high concentrations, and the FDA has warned against drinking it. There are no reports of people getting bird flu from drinking unpasteurized milk, but “it is possible” to become infected from it, Schaeffer said. Already, this has been shown in animals: This week, researchers reported that cats who drank raw milk from sick cows got bird flu and died within days.

But much about bird flu and milk is unknown, because the virus has never been found in cattle before now. That one in five milk samples tested by the FDA had remnants of bird flu doesn’t mean one in five cows tested positive; milk sold in stores is pooled from many different animals. Rather, it suggests that many cows may be infected beyond those currently accounted for. It may also mean that asymptomatic cows, which are not being tested, shed virus in their milk. (Milk from symptomatic cows, which can be yellow and viscous, is routinely discarded.) Although it isn’t clear how the virus is circulating among cows, a leading explanation is that it’s transmitted via contact with surfaces that have touched raw milk, including milking equipment, vehicles, and other animals.

Bird flu is widespread among poultry, but it isn’t clear how long it will keep circulating among cattle. The USDA is doing only limited testing of cows and has not shared all of its data publicly, making the full extent of the outbreak impossible to know. Even if milk is still safe to drink, the thought of bird-flu fragments swimming around in it is unappetizing for a country that has already turned away from milk.

Just how much milk Americans used to drink can be hard to grasp. Consumption peaked in 1945 at 45 gallons a person annually, enough to overfill a standard-size bathtub. Americans believed that “more milk makes us healthier” and drank accordingly, DuPuis said. Government marketing pushed milk as a necessary, perfect food that could solve virtually all nutrition problems, especially in children; milk-derived healthiness eventually became associated with strength, affluence, and patriotism. Holes in the health narrative have since appeared: Consuming too much milk and other dairy products is now considered unhealthy because of the fat content. And long-standing myths about milk, such as that its calcium is required for strengthening bones and growing taller, have largely been debunked.

Today, drinking milk can get you “milk-shamed” by people who think it’s disgusting. It’s particularly unpopular with younger people, who are grossed out by the milk served in schools. Where dairy once reigned supreme, milk alternatives made of oats, almonds, soy, peas, and countless other things have found a foothold. The FDA even lets plant-based milk call itself “milk,” as I wrote last year.

Less demand for milk would have consequences. “I suspect the dairy industry is on the edge of their seat,” DuPuis said. Outbreaks are expected to take a financial toll on farmers, who will not only sell less milk but also have to care for sick animals, and the costs may be passed on to consumers. In rural areas that once thrived on milk production, such as upstate New York, abandoned small farms are now overgrown with trees, DuPuis observed. “Are we going to end up with fewer farms and more trees because of this latest problem? I can imagine so,” she said.

The myth of milk has been eroded from many fronts: nutrition research, shifting societal norms, an abundance of new beverages. With bird flu, it has never seemed less like the magic health elixir it was once thought to be. But the turn against milk might have gone too far. Pasteurization was invented in the 19th century, yet it works to kill modern-day pathogens. Dairy has a great track record when it comes to safety, Polzin said. And it is still a decently healthy choice, with some significant advantages over plant-based alternatives, such as having more vitamins and minerals, less sugar, and more protein. Even during the bird-flu outbreak, milk may still have some magic to it.