If you produce or market a manufactured beverage, you really don’t want to find out Alissa Hamilton has written about it. Her 2009 book Squeezed: What You Don’t Know About Orange Juice exposed the political and economic forces that paved way to processed OJ becoming a breakfast staple. It also revealed the industry that markets its product as “pure” and “natural” uses chemically engineered “flavour packs” to keep it “fresh” for years, a finding that triggered a flurry of ongoing false-advertising, class-action lawsuits in the U.S.

Now, in Got Milked: What You Don’t Know About Dairy, the Truth About Calcium, and Why You’ll Thrive Without Milk, Hamilton examines the opaque white liquid institutionalized in the North American diet—and what she sees as bovine thinking about it. The Canada Food Guide lists “milk and its alternatives” as one of four food groups and calls for two daily servings for young children and adults, more for anyone over 50. Elementary school milk programs exist on the belief that growing bodies require dairy milk.

Hamilton, who has a Ph.D. in environmental studies from Yale, disagrees. The marketing mantra that milk provides “16 essential nutrients,” foremost calcium, has resulted in “fuzzy logic” in which the beverage itself is seen as essential, she writes. Non-animal sources of calcium—leafy greens, nuts, dried basil—are both healthier and more easily absorbed, she argues. Consumers have bought into “false notions of [milk’s] goodness,” overlooking its sugar, calories and cholesterol, Hamilton writes; cow’s milk has come to be seen as the natural extension of mother’s milk, even though humans are the only species to drink the milk of another.

Not only is milk not essential, it may be doing damage, contends Hamilton, who marshalls a body of troubling research, including the “calcium paradox” recognized by the World Health Organization that nations with the highest dairy consumption have the highest rates of bone fractures. International correlational studies have also linked higher milk consumption with cancers, including breast and prostate cancer. And our relationship with milk is unhealthy in more ways than one, Hamilton argues, outlining how dairy farming is more environmentally destructive than beef farming. Milk’s “privileged position in the North American diet” is exclusionary, she writes, given government edicts to consume a food group that many ethnicities, including Asians and Aboriginals, can have trouble digesting due to lactose intolerance. Thus milk’s not just unhealthy or terrible for the environment, it’s even, in a cardinal sin of our times, racist. Welcome to the new milk war.

Hamilton’s anti-lactic manifesto is far from the first salvo across the dairy industry’s bow. Vegan and environmental activists have pilloried milk for years, notably in PETA’s infamous 2007 “Got Pus?” campaign based on “Got Milk?”—the dairy-industry campaign that painted viscous milk moustaches on celebrities from Donald Trump to Taylor Swift. The 2014 documentary Cowspiracy: The Sustainability Secret, lambasted environmental groups for not singling out the environmental damage done by the dairy industry, alleging that 1,000 gallons of water are required to produce one litre of milk. The “ditch dairy” movement long ago began migrating from the fringe with the mainstreaming, even fashionability, of veganism. A galvanizing force was the 2005 book The China Study by Cornell University biochemist Colin Campbell and his physician son, Thomas Campbell, that linked dairy consumption to heart disease, diabetes, autoimmune conditions and certain cancers. One of the bestselling nutrition books of all time, it’s credited with turning Bill Clinton vegan.

But Hamilton’s book arrives at a seismic moment, one that finds a receptive audience to the anti-dairy message, and great interest in evidence that milk is bad for us. Dairy milk sales dropped some 40 per cent in North America between 1970 and 2011 due to changing habits and health concerns. Sales of packaged cereals (milk’s traditional delivery system) are in decline, a casualty of low-carb diets, ever-busier schedules and a proliferation of breakfast-on-the-go options; there’s more choice of beverages, and consumers are switching to soy- and nut-based milks. The exception is chocolate milk, sales of which are on the upswing due to its central place in school milk programs and the beverage’s new identity as a sports drink. It’s as hydrating as H20, the sell goes, with more nutrients.

Chocolate milk’s transformation into the new Gatorade is just one marker of the dairy industry regrouping and rebranding for its very survival. Its Darwinian knack for reinvention is legendary; Hamilton charts how the industry cleverly engineered new products to sell to the lactose intolerant. Last year, it scrapped the “Got Milk” campaign and began marketing milk as an essential part of an active life. It has also launched the premium “super-milk” category, led by Coca-Cola’s Fairlife, a lactose-free product introduced in the U.S. last year that contains 50 per cent more protein, 30 per cent more calcium and 50 per cent less sugar than regular milk—at twice the price. It’s not available in Canada, yet. Entering the country “is definitely under consideration as an important part of our expansion,” says Anders Porter, a Fairlife spokesman. Given that dairy is a supply-managed commodity in Canada, excluded from NAFTA, that could prove challenging. Imports are limited and the domestic market is fiercely protected by Canadian dairy conglomerates.

Meanwhile, in the U.S., dairy is also targeting the fast-food market, with government assistance. In the 2014 report Whitewashed: How Governments and Industry Promote Dairy Junk Food, public health lawyer Michele Simon outlines how the U.S. government offers financial incentives to fast-food chains that feature milk and cheese. Hence the arrival of McDonald’s specialty coffees that contain up to 80 per cent milk.

The market Coca-Cola is going after with Fairlife, though—people who want their food to confer premium status and maximum health payoff—is ironically the same one with whom Got Milked’s message will resonate: a mindset in which what’s eaten is driven as much by a sense of righteousness as by science. Respected nutritionist Marion Nestle, a professor at New York University, who hasn’t read Hamilton’s book, is in agreement with her that dairy products are not a necessary source of calcium. But she has no problem with the dairy food group as a part of the daily diet: “I’m not aware of convincing evidence that dairy products cause harm in moderate amounts,” she writes in an email.

That may not matter. The fact that “dairy” is now spoken of in the same glowering tone as “gluten” is more about food fashion than nutrition. In a “detoxing” era, what one doesn’t eat is as defining as what one does eat. For that audience, Got Milked’s message will justify joining the dairy-shunning bandwagon.

Sitting in a café near her house in downtown Toronto, Alissa Hamilton insists she’s not interested in taking down an industry: “I’m not demonizing milk and dairy,” she says, a statement that should strike fear in any target she actually wants to demonize. “Sure, have it in your coffee, have it if you’re not allergic. I simply want to point out the illogical premises.”

Hamilton does have an agenda, she admits, as she sips hot water (she doesn’t drink tea or coffee): she wants dairy eliminated as a separate food guide category, re-listed under protein. “We’d be forced to know a lot more about nutrients in vegetables, particularly calcium,” she says. “Milk having special status as a calcium source makes as much sense as pumpkin seeds being a food group because they’re high in magnesium,” she says.

To get people off what she calls the “dairy calcium crutch,” she includes some 40 pages of calcium-rich recipes headlined by leafy greens, grains, nuts and tinned salmon; there’s also instruction on how to toast eggshells to make calcium powder.

Milk wasn’t a household staple when she was growing up in Toronto, the 42-year-old says. Her family wasn’t anti-dairy: she ate yogourt and enjoyed raw cow’s milk when visiting a family friend’s farm. She was inspired to write the book after a childhood friend confessed she’d never served her two-year-old dairy milk and was worried it made her an unfit mother. The friend also had been raised without milk (her mother grew up in Europe during the Second World War and didn’t see milk as essential). “My first reaction was ‘That’s crazy,’ ” says Hamilton. But she also saw how calcium had become synonymous with milk in the public’s mind. Yet calcium is everywhere, she says, handing over a label from a package of soybean sprouts: a one-cup serving provides 46 per cent of daily calcium requirements. “That’s the equivalent of a glass and a half of milk—with only 30 calories.”

Like Squeezed before it, Got Milked dissects how institutional forces dictate what we eat. North American governments have a dual mandate that can be conflicted, she says: “They’re there to provide dietary guidelines and to promote agricultural commodities—and milk is a huge money-maker.” According to Dairy Farmers Canada, the dairy sector contributed $16.2 billion annually to Canada’s GDP and employed 218,300 people in 2011. No wonder, then, that calcium requirements in North American food guides are higher than elsewhere: “Three glasses a day equates to what the government thinks our calcium recommendation should be—somewhere around 1,000 milligrams.”

Hamilton cites a growing body of research that suggests too much calcium can cause health problems—from kidney stones to fractures. A Swedish study published last year in the British Medical Journal indicated drinking three glasses of milk per day coincides with an increased incidence of osteoporosis and bone fractures, and earlier mortality. Whether milk or other lifestyle factors is to blame isn’t explicit. “Correlation does not equal causation,” Hamilton says. “But epidemiological evidence is mounting.”

Isabelle Neiderer, the director of nutrition at Dairy Farmers of Canada, an industry lobby group, disagrees. “It’s a myth that countries that consume more dairy have higher fracture risk,” she says, citing other risk factors such as height, a sedentary lifestyle and smoking. Milk remains the most convenient calcium source, she says: “Plant-based calcium provides less calcium, cup for cup, and is less easily absorbed, with exceptions like kale and bok choy.” (Nestle argues there isn’t an advantage to either form: “Calcium is calcium,” she notes.) Neiderer also points to research, some of it industry-funded, that ties drinking milk to lower incidence of hypertension, cardiovascular disease, and type 2 diabetes; milk also provides protection from colorectal cancer, according to the World Cancer Research Fund. Such are milk’s benefits, says Neiderer, that even the lactose-intolerant shouldn’t avoid milk products: “Most cheeses have only trace lactose and can be well-tolerated.” People should find their level of tolerance, and try to increase it over time, she says.

As for Hamilton’s point that pediatricians are seeing anemia in toddlers who drink a lot of milk, Neiderer notes that “if young children consume excessive amounts of milk, they will likely underconsume other foods, including iron-rich foods.

School milk programs serving low-fat flavoured milks are another of Hamilton’s targets. She’s far from alone; British chef and children’s nutrition activist Jamie Oliver has also blasted them. The upshot is children drinking extra sugar to meet calcium requirements. Schools banning soda but offering low-fat chocolate milk is paradoxical, Hamilton writes: “The government is merely substituting sugar for sugar.” Neiderer disagrees: “Chocolate milk doesn’t increase risk of obesity and improves nutritional status.”

Not surprisingly, research on the topic funded by the industry bolsters Neiderer’s case. A study published this year in Applied Physiology, Nutrition, and Metabolism by researchers at the University of Saskatchewan, funded by the Dairy Council of Canada, analyzed the impact of removing chocolate milk from school milk programs in Saskatoon. Their conclusion? The drink is “more cost-efficient and convenient at providing nutrients than alternative food/drink combinations.”

As Hamilton presents it, milk’s “privileged” dietary position reflects cultural privilege—a milk-white imperialism. A 2005 study out of Cornell found 61 per cent of people studied were lactose intolerant, with a range of two per cent in Denmark and 100 per cent in Zambia. Hamilton quotes African-American physician Milton Mills, a long-time opponent of dairy as a separate food group, who testified at the 2015 USDA dietary guideline advisory committee that the majority of Asian Americans, Native Americans, African Americans and Mexican Americans are lactose intolerant. “If you go to China,” says Hamiliton, “not too many people will buy the message that cows’ milk is more authentic than soy milk.” The term “lactose intolerance” itself reflects bias, Hamilton says: “We should be talking about ‘lactase persistence.’ ” (Lactase is an enzyme required to digest lactose that many humans stop producing after being weaned.) Neiderer disagrees. Incidence of “lactase non-persistence” in studies doesn’t reflect actual rates of lactose intolerance, she says: “There’s no reason people who are lactose intolerant can’t enjoy dairy.”

That theory could be put to the test, given the industry’s incursion into Asia and China, where some countries report very high rates of lactose intolerance. “Osteoporosis has become a national health priority in China,” says Neiderer. And Hamilton quotes a spokeswoman for one of China’s biggest dairy producers: “One cup of milk can strengthen a nation.” It’s a sentiment echoed in racist Second World War American propaganda aimed at increasing consumption of fluid milk by belittling non-milk-drinking cultures, she writes. Hamilton’s book reproduces a “Men Without Milk” poster with an unflattering illustration of a Japanese soldier above the copy: “The short stature of the Japanese, their bowed legs, their frequent poor eyesight are all blamed on inadequate diet—particularly lack of milk!” More than 70 years later, it’s come full circle, she says: “Drinking milk is now being promoted in Thailand as a way to become taller.”

Hamilton’s current concerns are more local. She cites the Harvard School of Public Health’s alternative to the USDA “My Plate” dietary guidelines as a template. Where “My Plate” shows the dairy category as a blue circle, representing a glass, the Harvard group reassigned dairy and replaced the blue circle with a glass of water. “Imagine, when kids start asking for water with meals, we’ll be on the way to a far more healthy nation, and world,” Hamilton says. “It would spark a revolution in eating habits.”

Editor’s note: This story has been updated to reflect the following changes: the daily recommendation for calcium is “somewhere around 1,000 milligrams,” not millilitres; milk is being marketed as a way to increase height in Thailand, not Taiwan.