United States raw milk debate

Pasteurization was first used in the United States in the 1890s after the discovery of germ theory to control the hazards of highly contagious bacterial diseases, including bovine tuberculosis and brucellosis, that could be easily transmitted to humans through the drinking of raw milk.[12] Initially after the scientific discovery of bacteria, no product testing was available to determine if a farmer's milk was safe or infected, so all milk had to be treated as potentially contagious. After the first test was developed, some farmers actively worked to prevent their infected animals from being killed and removed from food production, or would falsify the test results so that their animals would appear to be free of infection.[13]

In the United States, milk pasteurization became "widespread" in the 1920s and it was considered "one of the major breakthroughs in public health".[6] In 1924, "Grade A Pasteurization" became recommended federal policy, but interstate commerce of unpasteurized dairy products was only limited via federal legislation in 1987.[7]

In 2009, 29 U.S. states allowed sales of raw milk in some form.[11] 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.[14] In April 2013, the state of North Dakota passed a law that authorizes the use of herd shares.[15]

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.[16] Reuters named the raw milk debate as first on a list of the top eight health issues of 2008.[17] The FDA has also offered financial assistance to state departments of health to help reduce raw milk consumption.[14]

Pasteurization is credited with dramatically reducing pathogens found in milk. This improves the shelf-life and safety of the processed milk. Advocates of drinking raw milk claim various health benefits they attribute to raw milk that are lost in the pasteurization process,[18] and claim that raw milk can be produced as hygienically as pasteurized milk.[19] Raw milk advocates may go as far as to claim that untreated milk is a "miracle cure" for illnesses such as asthma or gastrointestinal disorders.[20] A 2006 systematic review of infections associated with raw milk contends that pasteurized milk is both substantially safer and comparably nutritious to raw milk, concluding there is no scientific reason for choosing raw milk products over pasteurized milk products.[21] Similarly, a recent review authored by the Belgian Federal Agency for the Safety of the Food Chain and experts from Belgian universities and institutions concluded that "raw milk poses a realistic health threat due to a possible contamination with human pathogens. It is therefore strongly recommended that milk should be heated before consumption. With the exception of an altered organoleptic [flavor] profile, heating (in particularly ultra high temperature and similar treatments) will not substantially change the nutritional value of raw milk or other benefits associated with raw milk consumption."[22]

Pasteurization opponents say that raw milk contains bacteria beneficial to the human digestive system,[23] but pasteurization is not selective and affects all bacteria whether beneficial or infectious. These bacteria include species considered to be probiotics, 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 amines in the blood of dialysis patients with small bowel bacterial overgrowth, aided lactose digestion in lactose-intolerant subjects, and a reduction in coronary heart disease risks.[24][25] However, food scientists and FDA officials maintain that such "good bacteria" can be found in pasteurized products, including yogurt,[26] and argue that the destruction of pathogens far outweighs any proposed benefit to keeping the beneficial microbes alive.[27]

According to a 2009 review, milkborne disease outbreaks made up approximately 25% of all food and water contamination disease outbreaks in 1938; pasteurization is largely credited for a dramatic decrease in milkborne disease outbreaks, which made up less than 1% of food and water contamination disease outbreaks by 2005.[2]

According to the Centers for Disease Control and Prevention, 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."[27]

In 2006, the California Department of Food and Agriculture temporarily quarantined milk and cream from Organic Pastures, California's largest raw milk producer, after four children were stricken with E. coli O157:H7 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."[28]

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 immune systems, 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[29] and American Academy of Pediatrics, also warn that raw milk is dangerous, especially for children.[7]

The Centers for Disease Control (CDC) cite 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.[30] 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.[31] In 2007, Kansas State University published a list of outbreaks[32] associated with consuming raw milk or dairy products and an article[33] about the investigation of raw milk outbreaks.

The Weston A. Price Foundation has been active in promoting raw milk with its "Real Milk" campaign.[18] 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.[34] 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".[35]

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.[36]

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.[37]

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.[38][39]

Advocates of drinking raw milk claim raw milk contains desirable substances, such as enzymes, that cannot survive the heating process and may be destroyed during pasteurization; specifically, immunoglobulins and the enzymes lipase and phosphatase, which are inactivated by heat, are believed to be beneficial.[40] In contrast, food scientists and FDA officials assert that most "beneficial" enzymes survive pasteurization; that those few enzymes that are present in raw milk and denatured in pasteurized milk are ultimately degraded in the low pH environment of the stomach anyway; and that the enzymes present in milk are not used by humans to metabolize nutrients.[22][27]

Pasteurization does lead to decreased levels of several vitamins, but only approximately 0–10%.[27] Research shows only very slight differences in the nutritional values of pasteurized and unpasteurized milk.[22] Raw milk contains very little vitamin D, which is added to processed milk.[18][27]

Three studies have found a statistically significant inverse relationship between consumption of raw milk and asthma and allergies.[41][42][43] However, all of these studies have been performed in children living on farms and living a farming lifestyle, rather than comparing urban children living typical urban lifestyles and with typical urban exposures who do or do not consume raw milk, so it is likely that other aspects of the overall urban vs. farming environment lifestyle play a role in these effects; for this reason, the overall phenomenon is termed the "farm effect." In the largest of these studies,[44] exposure to cows and straw as well as raw milk were associated with lower rates of asthma, and exposure to animal feed storage rooms and manure with lower rates of atopic dermatitis.[44] A recent scientific review concluded that “most studies alluding to a possible protective effect of raw milk consumption do not contain any objective confirmation on the raw milk status or a direct comparison with heat-treated milk. Moreover, it seems that the observed increased resistance seems to be rather related to the exposure to a farm environment or to animals than to raw milk consumption.”[22]

Many raw milk consumers cite a preference for the taste of raw milk products.[18]

The Raw Milk Cheesemakers Association hold that cheese produced from raw milk have distinctive complexity and depth of flavor absent from pasteurized-milk cheeses.[45]

The FDA considers hard, aged cheese, such as parmesan and cheddar, made from raw milk to be generally safe for consumption; soft cheese made from raw milk is considered unsafe.[46] These types of cheese are currently legally sold if aged for 60 days or more.[35] Over this period, the salt and acid characteristics of aging cheese generally eliminate the growth of pathogenic bacteria.[47]