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Explainer
The global dairy industry produces nearly 550 million metric tons of cow’s milk each year. But which products are dairy and how are they made?
Words by Jennifer Mishler
The global dairy industry produces nearly 550 million metric tons of cow’s milk each year from an estimated 260 to 270 million cows. In the U.S., the dairy industry has become increasingly concentrated, with smaller dairy farms going out of business and larger industrial dairies producing most milk and other dairy products like cheese and yogurt. The number of dairy farms has dropped by half since 2006, and yet the nation’s milk production has risen by 24 percent.
Dairy products are foods and beverages containing milk obtained from a lactating animal, most often cows. Other species used include buffalo, goats, sheep and camels.
Many products fall within the dairy category:
Milk is the basis of all other dairy foods. Cow’s milk is nearly 90 percent water, but it also contains protein, fat and minerals. Most of the dairy milk sold in the U.S. is also fortified with vitamin D.
Like humans and other mammals, cows lactate and produce milk after giving birth. The production of cow’s milk relies on a cycle of impregnating animals each year, followed by the routine separation of mothers from their calves within hours or days of birth. This allows dairy producers to sell the milk of lactating cows for human consumption, rather than allowing calves to nurse. Many male calves born into the dairy industry go to veal, while females most often remain on dairy farms but are ultimately slaughtered and sold as beef.
Cows are typically milked two or three times each day, and because of the unprecedented amount of milk produced in today’s industry, many farms in the U.S. and other countries now employ machines that, attached to the animals’ udders, milk them mechanically. Selective breeding, the use of hormones and changes to the diets of farmed cows have all contributed to the soaring production of milk as the number of cows has remained roughly static for decades. Over 70 percent of the nation’s milk now comes from farms housing 500 cows or more.
Cream is obtained by skimming off the layer of fat found at the top of milk prior to homogenization, the process which lowers the fat content of dairy milk and makes its color and texture more consistent.
Heavy cream must contain at least 36 percent milk fat and undergoes pasteurization or ultra-pasteurization, according to the FDA. A pasteurized dairy product has been sterilized through heat to make it safer to consume.
Producers churn milk or cream to create butterfat, which is more concentrated than milk fat. Butter is as much as 80 percent fat, along with water, protein and other milk solids.
Many different butter products exist, from sticks of solid butter to whipped butter, as well as salted and unsalted. Margarine is similar, but is made with oils instead of milk or cream so largely contains unsaturated rather than saturated fat.
The base ingredients of dairy cheese are typically milk, salt, bacteria and an enzyme known as rennet. The latter, obtained from the stomach lining of calves, lambs and young goats, is a controversial ingredient that leads many to consider dairy-based cheese a nonvegetarian food.
Cheese comes in countless varieties including mozzarella, cheddar, provolone and parmesan, and may be sold in further processed forms such as powdered or liquid cheese. It is also widely used as an ingredient in finished dishes such as pizza or macaroni and cheese.
Globally, the cheese market is expected to surpass a value of $160 billion by 2028.
Yogurt, like cheese, is made through the fermentation of milk. In the case of yogurt, specific bacteria are used.
Yogurt often contains sweeteners and thickeners, and comes in many flavors. Sometimes it includes chunks of berries or fruit. Yogurt is consumed as is or can be used in cooking and baking, especially in its original flavor.
Greek yogurt is made by straining the whey from more liquid-like original yogurt to create a denser product.
Dairy fermentation is the process of using bacteria to break down the sugar (lactose) in milk, creating lactic acid.
Products made from fermented or cultured milk include cheese, sour cream, cottage cheese, yogurt and kefir.
Containing eggs and milk or cream, custard is a cooked gelatinous product often used as a topping or filling in desserts or eaten on its own. It is similar to pudding but firmer, although cornstarch or other thickeners are used in place of eggs to make pudding.
Ice cream is the most common and popular frozen dairy product, made by churning and freezing milk, cream, sweeteners and other ingredients.
The global ice cream market was worth over $70 billion in 2021, and the U.S. alone produced 1.3 billion gallons in 2021.
Gelato is Italian-style ice cream, which is often thicker as less air is incorporated during mixing. Other dairy foods that are sold frozen include sherbet, yogurt, custard and many ice cream-related products such as pre-packaged cones and cakes.
Casein is the main protein in dairy milk, it is a phosphoprotein (containing phosphorus) and is responsible for the white color of the fluid. Offering much of the nutrition found in cow’s milk, casein contains calcium and essential amino acids.
Casein is sometimes used in nonfood products as well, including adhesives, paint and plastic.
Milk is considered by many health agencies to be important for bone health, as a source of calcium, and it also contains vitamin B12, potassium, vitamin A and other nutrients. Yet milk’s importance when it comes to strong bones is not conclusively proven. The Harvard T.H. Chan School of Public Health writes that, “research has not shown a consistent benefit on bone health with high intakes of milk, and furthermore has suggested potential harm with certain conditions like prostate cancer.”
Still, in the U.S. and many other countries, the dairy food group holds a prominent place in dietary guidelines. In fact, the USDA states that around 90 percent of Americans do not consume enough dairy.
Some consumers may avoid dairy in their diet. Reasons for eschewing dairy can vary and also overlap: Some shoppers have a dietary need, others object to the treatment of cows and other animals raised for milk and some may be concerned with the health risks of dairy consumption. Many are also increasingly aware of the heavy carbon footprint of the dairy industry.
Cow’s milk is to be avoided in infants younger than 1 year old, according to the CDC, as its consumption prior to this age could lead to intestinal bleeding. It contains more proteins and minerals than an infant’s kidneys can process and is not nutritionally adequate to replace human breast milk or baby formula.
Those with an allergy to milk, most commonly seen in infancy and early childhood, must often avoid both milk itself and milk as an ingredient in finished dairy products. Because some are allergic to dairy and its derivatives, milk is clearly listed on U.S. food labels along with any other common allergens a product may contain, such as nuts, eggs, wheat and soy.
While some who are lactose intolerant may avoid dairy entirely, others consume dairy products made without lactose. Milk producers achieve this by adding lactase, an enzyme naturally produced by the human body to break down lactose, but typically not produced sufficiently in those with lactose intolerance. Globally, the lactose-free dairy market is projected to continue an upward trend, reaching a value of $18.4 billion by 2028.
While vegetarians who do not eat conventional meat do consume dairy, vegans avoid all dairy and other animal byproducts in their diet. To serve this base and, increasingly, many other consumers, a vast and growing variety of dairy alternatives made from soy, almonds, oats and other plant sources are sold in stores and found on menus around the world.
According to the Food and Agriculture Organization (FAO) of the U.N., milk and its related products are consumed by more than 6 billion people around the world. In economically developing countries, milk consumption per capita has nearly doubled since the early 1960s.
In 2022, India was the top consumer of fluid milk, at over 85 million metric tons. This was followed by the more than 23 million tons and 20 million tons consumed by the E.U. and U.S. respectively.
Milk, while growing in popularity around the world, is still most heavily consumed in Western nations, which have typically emphasized the dairy food group in their dietary guidelines. Dairy milk accounts for 19 percent of dietary protein in Europe, while providing between 5 percent and 8 percent in Africa and Asia, according to the FAO. In the Americas, Europe and Oceania milk offers between 12 percent and14 percent of dietary fat, compared to between 6 percent and 7 percent in Africa and Asia.
Many people, especially those of us in Western societies, are raised to believe that dairy is an essential part of a balanced diet, needed especially for bone health. Yet many of the vitamins, minerals and other nutrients found in animal-derived milk can be obtained from plant-based foods.
Around 70 percent of people worldwide suffer from a condition called lactose intolerance. This refers to the inability to completely digest lactose, the sugar present in dairy milk. While this intolerance is generally not considered serious, symptoms brought on by lactose consumption can include bloating, diarrhea and gas.
Between 30 million and 50 million people in the U.S. are lactose intolerant, and the condition disproportionately impacts people of color: 90 percent of Asian Americans and 80 percent of African Americans and Native Americans are affected by lactose intolerance.
Dairy does not have a clear link to cancer. Some studies have indicated that there could be an elevated risk of cancer associated with high levels of dairy consumption, notably prostate cancer. However, studies have also indicated that dairy may reduce the risk of colorectal cancer, and for this reason the American Cancer Society makes no recommendation on dairy consumption.
Researchers continue to study this question. In May of 2022, a study published in BMC Medicine including data from over 500,000 people in China compiled over 11 years, found that for every 50 grams of dairy consumed daily, risk of liver cancer rose by 12 percent and that of breast cancer increased by 17 percent.
The following month, a study published in the American Journal of Clinical Nutrition found that the risk of prostate cancer rose by 25 percent in men consuming approximately one and three-quarter cups of dairy each day when compared to those who consumed half a cup per week.
The beef industry often gets the focus of cattle farming’s environmental footprint, but the dairy industry has a detrimental impact as well. Between 2005 and 2015, the global dairy sector’s emissions rose by 18 percent as herd size and milk production increased. Through deforestation and the growing of feed crops, the digestive processes of the cows themselves, gasses released by large stores of manure and other processes, dairy production is now responsible for nearly 3 percent of all human-related greenhouse gasses released into our atmosphere.
Intensive dairy farms also pollute waterways by milk spills, dumping waste and overflow from the vast lagoons used to store cattle manure. Nutrient runoff seeps into surrounding rivers, which can lead to toxic algal blooms and the growth of bacteria harmful to aquatic life. Rivers are also a vital source of safe drinking water for many communities.
Dairy-free products contain no milk derived from cows or other animals, and no derivatives of animal-based milk such as whey or casein. Other ingredients, such as lactic acid, are sometimes obtained from dairy milk but can also come from plant sources. This will sometimes be indicated on the label.
Some dairy-free foods and beverages may contain no dairy alternative at all, as milk is simply not needed for those products, and others may contain one or more of a wide variety of plant-sourced milk ingredients. Alternatives to dairy can include milks produced from soy, oats, nuts, rice, legumes and other foods. There are also cultured dairy products which are dairy, yet produced without harm to animals.
Globally, the dairy alternatives market was worth over $27 billion in 2022 and is projected to exceed $44 billion by 2027.
Eliminating dairy from one’s diet and choosing from nutritious plant-rich alternatives is the most effective way to reduce the negative impacts of dairy production, including animal suffering, water pollution and climate emissions. Other ways to make a positive impact can be found on Sentient Media’s Take Action page.
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