The United States raw milk debate concerns issues of food safety and claimed health benefits of raw milk (unpasteurized and unhomogenized), and whether authorities responsible for regulating food safety should prohibit the sale of raw milk for consumption.
Raw milk makes up a small proportion of US general population milk consumption. However, some claim the demand for raw milk has "considerably increased in recent years". Raw milk advocates falsely claim a variety of health benefits attributable to untreated dairy products; government officials and scientific researchers stress that there are substantial food safety risks associated with raw milk, and that claims of health benefits provided by raw milk are unsupported by scientific evidence.
Homogenization
Homogenization is a process that reduces the size of fat globules by forcing pressurized, hot milk through small holes, causing turbulence that breaks up the larger fat globules so that they remain suspended rather than separating in a cream layer at the top. The purpose of homogenization is to make milk more convenient to process, store and consume, eliminating the need to shake or stir the milk container to remix the separated cream layer and increasing the shelf-life of the product.
Those opposed to homogenization argue that decreasing the size of fat globules may have unhealthy effects, including allowing steroid and protein to bypass normal digestion and increase their levels in the body. Concerns that uptake of the protein xanthine oxidase is increased by homogenization, leading to hardening of the arteries (atherosclerosis), were raised in the 1970s. Subsequent research "failed to substantiate, and in many cases has refuted" a plausible effect of xanthine oxidase from homogenized milk on cardiovascular disease.
Scientific studies are somewhat limited but do not currently support claims that milk homogenization affects the development of atherosclerosis, coronary heart disease, milk allergy and milk intolerance, Type I diabetes or Type II diabetes.
Pasteurization is widely accepted to improve the safety of milk products by reducing the exposure to pathogens. Opponents of pasteurization argue that unpasteurized milk has benefits associated with superior taste, nutritional qualities and certain health benefits over pasteurized milk. While pasteurization of milk kills off bacterial pathogens, other bacteria species with possible health benefits are also destroyed. Pasteurization of cow's milk destroys any potential pathogens and increases the shelf life. During pasteurization, however, these lactic acid bacteria are mostly destroyed. A 2009 systematic review of the food safety of unpasteurized milk concluded that science-based data to substantiate claims of health benefits "are lacking or do not exist" and the risks associated with disease outbreaks as a result of raw milk consumption are "considerably higher".
Chicago became the first American city with a mandatory milk pasteurization law in 1909. New York city followed with similar laws in 1914. Within a decade after New York city started enforcing milk pasteurization, infant mortality fell by more than two thirds.
In the United States, milk pasteurization became "widespread" in the 1920s and it was considered "one of the major breakthroughs in public health". In 1924, "Grade A Pasteurization" became recommended federal policy, but interstate commerce of unpasteurized dairy products was only limited via federal legislation in 1987.
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In 2009, 29 U.S. states allowed sales of raw milk in some form. In other parts of the world, raw milk can often be bought directly from the farmer. Arizona, Utah, California and Washington allow raw milk sales in retail stores with appropriate warning labeling. As of May 2010, Massachusetts only allowed direct sales from farm to consumer, resulting in "buying clubs" where consumers pool transportation resources to obtain raw milk more conveniently. In April 2013, the state of North Dakota passed a law that authorizes the use of .
In late 2007, the debate received media attention in California, where limits on the bacterial counts legally allowed in commercial raw milk came up for legislative review. Reuters named the raw milk debate as first on a list of the top eight health issues of 2008. The FDA has also offered financial assistance to state departments of health to help reduce raw milk consumption.
Pasteurization opponents say that raw milk contains bacteria beneficial to the human digestive system, but pasteurization is not selective and affects all bacteria whether beneficial or infectious. These bacteria include species considered to be , such as Lactobacillus acidophilus, useful for the culturing of yogurt and cheese. Fermented milk products with levels of L. acidophilus significantly higher than those found in raw milk have been associated with decreased incidence of pediatric diarrhea, decreased levels of toxic in the blood of Kidney dialysis patients with small bowel bacterial overgrowth, aided lactose digestion in lactose-intolerant subjects, and a reduction in coronary heart disease risks. However, food scientists and FDA officials maintain that such "good bacteria" can be found in pasteurized products, including yogurt, and argue that the destruction of pathogens far outweighs any proposed benefit to keeping the beneficial microbes alive.
According to the Centers for Disease Control and Prevention (CDC), more than 300 people in the United States got sick from drinking raw milk or eating cheese made from raw milk in 2001, and nearly 200 became ill from these products in 2002. "Drinking raw milk or eating raw milk products is like playing Russian roulette with your health," says John Sheehan, director of the Food and Drug Administration's Division of Dairy and Egg Safety. "We see a number of cases of food-borne illness every year related to the consumption of raw milk."
In 2006, the California Department of Food and Agriculture temporarily quarantined milk and cream from Raw Farm, California's largest raw milk producer, after four children were stricken with bacterial illness. The department determined that the common link in all four cases "was consumption of raw milk or raw colostrum from Organic Pastures in the week prior to symptom onset."
Milk collected or stored in unsanitary conditions may harbor a host of disease-causing organisms (pathogens), such as tuberculosis (Mycobacterium bovis), the bacteria Campylobacter (Campylobacteriosis), Escherichia E. coli O157:H7), Listeria (Listeriosis), Salmonella (Salmonellosis), Yersinia (Yersinia enterocolitica), and Brucella (Brucellosis). Pasteurization consistently removes all of these pathogens, allowing dairy farms that pasteurize their milk to have unsanitary facilities without the attendant outbreaks of disease that would occur if a raw milk dairy kept its herds in similar unsanitary conditions. The pathogens can be reintroduced if the milk is handled carelessly.
People with weakened , such as elderly, children, and those with certain diseases or conditions, are most at risk for severe infections from pathogens that can contaminate raw milk. In pregnant women, Listeria monocytogenes-caused illness can result in miscarriage, fetal death, or illness or death of a newborn infant, and Escherichia coli (E. coli) infection has been linked to hemolytic uremic syndrome, a condition that can cause kidney failure and death. Other groups, such as the Center for Food Safety and Applied Nutrition and American Academy of Pediatrics, also warn that raw milk is dangerous, especially for children.
The CDC cites numerous cases of serious or fatal infections caused by raw milk, with E. coli O157:H7 being the most important because it can cause hemolytic-uremic syndrome, a life-threatening condition. In a CDC report, numerous cases were traced to raw milk from a cow-share program in Cowlitz County, Washington. After five children were hospitalized, a court order was issued to bring the farm into compliance. In 2007, Kansas State University published a list of outbreaks associated with consuming raw milk or dairy products and an article about the investigation of raw milk outbreaks.
The Weston A. Price Foundation has been active in promoting raw milk with its "Real Milk" campaign. The organization claims that of 15 milk-borne disease outbreaks cited by the FDA, not a single one demonstrated that pasteurization would have fixed the problem, that 93% lacked either a valid statistical correlation with raw milk or a positive sample, and half lacked both; they further claimed that, even with the FDA's numbers, raw milk was no more dangerous than deli meats. FDA rebuttal , Weston A. Price Foundation In response, the director of the FDA's division of plant- and dairy-food safety, John Sheehan, called the organization's claims on the health benefits and safety of raw milk "false, devoid of scientific support, and misleading to consumers".
In 2008, scientists discovered that raw milk contains more species of bacteria than previously thought, and identified Chryseobacterium oranimense as well as C. haifense and C. bovis, but the amount found in raw milk has not been proven harmful.
While causation has not been determined, researchers in 2015 found that 59% of people with breast cancer had bovine leukemia virus (BLV) in their breast cancer samples, compared to the virus being found in only 29% of tissue samples of people who had never had breast cancer. BLV is common, spread by blood and milk in cows, and has been found in 100% of bulk milk tanks in dairy operations with over 500 cows. Consuming unpasteurized milk or undercooked meats could be pathways for human exposure to BLV.
In November 2017, the US Centers for Disease Control and Prevention recommended medical treatment for anyone who had within the previous six months consumed raw milk products from Udder Milk, a New Jersey–based cooperative. An antibiotic-resistant strain of Brucella abortus, which can cause the disease Brucellosis, was detected in at least one person who drank raw milk from the co-op.
Pasteurization does lead to decreased levels of several , but only approximately 0–10%. Research shows only very slight differences in the nutritional values of pasteurized and unpasteurized milk. Raw milk contains very little vitamin D, which is added to processed milk.
The Raw Milk Cheesemakers Association hold that cheese produced from raw milk have distinctive complexity and depth of flavor absent from pasteurized-milk cheeses.
The FDA considers hard, aged cheese, such as parmesan and Cheddar cheese, made from raw milk to be generally safe for consumption; soft cheese made from raw milk is considered unsafe. These types of cheese are currently legally sold if aged for 60 days or more. Over this period, the salt and acid characteristics of aging cheese generally eliminate the growth of pathogenic bacteria.
Somatic cells originate only from inside the animal's udder, while bacteria are usually from external contamination, such as insufficient cleaning of the milk transport equipment or insufficient external cleansing of the cow's udder and teats prior to milking. Milking equipment can also be accidentally knocked or kicked off an animal onto the floor, and contaminants on the barn floor can be sucked into the milk line by the system vacuum. A filter sock or filter disk in the pipeline prevents large particulate contaminants from entering the milk bulk tank, but cannot remove bacterial contamination once it has occurred.
For example, as defined by the state of Indiana’s administrative code, Grade A milk shall meet the following standards:
Milk not meeting these standards shall be designated as undergrade. Undergrade milk may not be sold for human consumption or processing into products for human consumption.
As established, these measurements are taken daily from the milk bulk tank and not from individual cows. This is because testing of individual animals at each milking would be expensive, but it also means that milk from a sick cow is diluted and averaged down by the healthy animals. Greater bulk tanks at very great commercial farms are accommodating of more sick animals in the herd, without the sick animals affecting the overall milk quality rating.
As discussed in the paper Guidelines for Using the DHI Somatic Cell Count Program
Bacteria in milk can come from sources other than the animal. Over time the milking pipeline and equipment can become coated with residues such as milkstone which are not removed by standard detergents and require periodic flushing of equipment with high strength corrosives. Automatic washing equipment for the bulk tank may not effectively clean all interior surfaces, and does not clean the exterior of the bulk tank at all.
Most milk marketers award producers for having a low SCC milk. Producers are incentivized to produce low SCC milk through the federal marketing order SCC adjustment rate. Milk marketers with a large presence in the cheese manufacturing may offer additional premiums for low SCC milk, as there is an increase in cheese yield.
Pasteurization
History
Legal status
Health effects of pasteurized milk
Pathogens and public health concerns
Nutrients in milk
Protection against non-infectious disease
Sensory experiences of pasteurized and un-pasteurized products
Personal choice
Quality standards for milk
External links
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