Difference between revisions of "United States raw milk debate"

Latest revision as of 18:37, 13 October 2010

The United States raw milk debate concerns issues of food safety and supposed health benefits of raw (not pasteurized, not homogenized) milk, and whether authorities responsible for regulating food safety should prohibit sale of raw milk for consumption.

Homogenization debate

Unprocessed milk consists of globules of milk fat suspended in a watery base containing dissolved proteins, sugars, vitamins, and minerals. If the globules are large enough, as with unprocessed milk from cows, the fat globules float upwards until they form a distinct cream layer at the top. Some animals, such as goats, produce smaller fat globules that remain mixed unless mechanically separated by centrifugation. Homogenization is a process which reduces size of fat globules by pumping milk through small holes causing turbulence which breaks up the larger fat globules so that they remain suspended rather than separating in a cream layer at the top. Homogenization has no purpose other than to make milk more convenient to process and consume, by eliminating the need to shake or stir the milk container to remix the separated cream layer.^{[citation needed]}

Homogenization opponents say that decreasing the size of fat globules has unhealthy effects, including allowing steroid and protein hormones to bypass normal digestion and increase their levels in the body.^{[citation needed]} Contradictory claims by opponents say that uptake of the protein xanthine oxidase is increased by the same size difference, leading to hardening of the arteries (atherosclerosis). Scientific studies on the effects of homogenization on dairy allergies and atherosclerosis have failed to show any link between these diseases and homogenization.^{[citation needed]}

Pasteurization debate

Pasteurization is a sanitation process in which milk is heated briefly to a temperature high enough to kill pathogens, followed by rapid cooling. Different times and temperatures may be used by different processors, often 165 degrees Fahrenheit for 15 seconds. Milk is tested following Pasteurization to confirm that bacteria have been killed to an acceptable level. Pasteurization kills pathogenic bacteria which occasionally may be present in milk, including those causing tuberculosis, listeriosis, salmonellosis, and several other diseases, but may not kill some resistant bacteria which eventually cause souring and spoilage of fresh milk. UHT pasteurization (Ultra High Temperature) is a more extreme form of pasteurization heating milk to a temperature high enough to kill spoilage organisms also.

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. A 2009 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".^[1]

History

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.^[2] 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.^[3]

Legal status

In 2009, 29 U.S. states allowed sales of raw milk in some form.^[1] In other parts of the world, raw milk can often be bought directly from the farmer. In England, about 200 producers sell raw or "green top" milk direct to consumers, either at the farm or through a delivery service. Raw milk is sometimes distributed through a share program, wherein the consumer owns a share in the dairy animal or the herd and can be considered to be consuming milk from her or his own animal. In the United States Arizona, California and Washington allow raw milk sales in retail stores with appropriate warning labeling. As of May 2010, only Massachusetts allows direct sales from farm to consumer, resulting in "buying clubs" where consumers pool transportation resources to obtain raw milk more conveniently.^[4]

In late 2007, the debate received media attention in California, where limits on the bacterial counts legally allowed in commercial raw milk have come up for legislative review.^[5] The news agency Reuters named the raw milk debate as first on a list of the top eight health issues of 2008^[6]. In November 2007, United States Congressman Ron Paul introduced a bill (HR 4077) to legalize interstate transportation of raw milk.^[7][8] The FDA has also offered financial assistance to state departments of health to help reduce raw milk consumption.^[4]

Arguments of raw milk supporters

Advocates of drinking raw milk name various health benefits they attribute to raw milk that are lost in the pasteurization process, and claim that raw milk can be produced as hygienically as pasteurized milk.^[9][10] Pasteurization opponents say that raw milk contains bacteria beneficial to the human digestive system,^[11] but pasteurization is not selective and impacts all bacteria whether beneficial or infectious. They also claim raw milk contains enzymes and other substances which cannot survive the heat process and which may be destroyed during pasteurization, specifically immunoglobulins and the enzymes lipase and phosphatase, which are inactivated by heat.^[12] Raw milk contains vitamin B₆, but the heat treatment may cause as much as 20% of the vitamin to be lost.^[13] Pasteurization also kills some of milk's naturally-occurring bacteria, such as Lactobacillus acidophilus, useful for the culturing of yogurt.

Two studies found a statistically significant inverse relationship between consumption of raw milk and asthma and allergies.^[14][15]

Cheesemakers hold that cheeses produced from raw milk have distinctive complexity and depth of flavor absent from pasteurized-milk cheeses.^[16] Ultra-pasteurized and UHT-treated milk is nearly impossible to use for cheesemaking.^[17]

The Weston A. Price Foundation has been active on this side of the debate, with its "Real Milk" campaign. A slide by slide rebuttal to the FDA Power Point presentation, claims that of 15 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. Even with the FDA's numbers, raw milk was cited as being no less dangerous than deli meats.

Arguments of pasteurization supporters and public health concerns

According to the Center 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." ^[18]

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."^[19]

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, though they can be reintroduced if the product is handled carelessly. Common symptoms of food-borne illness from many of these types of bacteria include diarrhea, stomach cramps, fever, headache, vomiting, and exhaustion. Healthy adults typically recover from such food-borne illness within a short time, but others (such as tuberculosis) have symptoms that are chronic, severe, or life-threatening.

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. Non-governmental groups such as the American Academy of Pediatrics also warn that raw milk is dangerous (especially for children).^[20] and the Center for Food Safety and Applied Nutrition (CFSAN) is also opposed.^[21]

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 the hemolytic-uremic syndrome, a life-threatening condition.^[22] 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.^[23] In 2007, Kansas State University published a list of outbreaks^[24] associated with consuming raw milk or dairy products and an article^[25] about the investigation of raw milk outbreaks.

A review of infections associated with raw milk contends that pasteurized milk is just as nutritious as raw milk, so that there is no scientific reason for choosing raw milk products.^[26]

The health of dairy animals can be managed by continual testing of dairy herds and careful storage of milk products, but some pathogens cannot be eliminated from dairy herds since the pathogens are carried by common wildlife (goats, cats, dogs, pigs, buffalo, badgers, possums, deer, and bison).^[27]

In 2008 scientists discovered that raw milk contains more 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.^[28]

Arguments regarding higher standards for raw milk

The methods of determining Grade A milk quality are well established, typically related to a measurement known as the somatic cell count (SCC) and the bacteria plate count. Generally a lower somatic cell count indicates better animal health, while the bacteria plate count indicates improved equipment sanitation.

Somatic cells originate only from inside the animal's udder, while the bacteria are usually from external contaminations, 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 administrative code,^[29] Grade A milk shall meet the following standards:^[30]

• The bacterial estimate classification shall be "acceptable".
• The bacteria count using the standard plate count, direct microscopic count, or plate loop count methods shall be not more than one million (1,000,000) bacteria per milliliter.
• The somatic cell count shall be not more than one million (1,000,000) cells per milliliter.
• The milk shall not contain drug residues.

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^[31]

• The results of many studies suggest that cows with SCC of less than 200,000 are not likely to be infected with major mastitis pathogens, but cows with SCC above 300,000 are probably infected (Smith, 1996).
• Herds with bulk tank SCC above 200,000 will have varying degrees of subclinical mastitis present. Data from the National Mastitis Council (1987) show that 6% of the [udder] quarters in a herd could be expected to be infected in a herd with a bulk tank SCC of 200,000.
• At 500,000 SCC, 16% of the quarters may be infected with a 6% reduction in milk production compared to a SCC of 200,000.

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.

Some buyers award producers for having the lowest SSC but this does not also lead to an increased payment for the milk quality, so there is no incentive to strive for anything more than meeting the basic grade A SSC rating.

Image management of Grade A milk

Raw milk could be held to a higher standard than regular pasteurized milk, but that would then create a public perception that standard milk quality ratings are inferior. Organizations such as the Center for Global Food Issues operate websites such as Milk is Milk which work to combat "misleading marketing practices" about general milk quality.

Critics such as the Union of Concerned Scientists contend that the CGFI is "funded by corporate agribusiness, chemical and pesticide manufacturers, the biotechnology industry, and others" and "opposes organic farming and efforts to reduce the use of medically important antibiotics in farm animals, while supporting the crowding of animals onto factory farms."^[32]

References

External links

This article's use of external links may not follow Wikipedia's policies or guidelines. Please improve this article by removing excessive and inappropriate external links. (May 2009)

The public debate

• "Should This Milk Be Legal?", New York Times, August 8, 2007
• "Got Raw Milk?", Boston Globe, March 23, 2008
• Got Raw Milk? Be Very Quiet, Time, March 13, 2007
• The Pernicious Practice of Feeding Distillery Slop to Dairy Cows

Warnings about raw milk

• Consumers’ growing enthusiasm for raw milk -- risks remain
• Pasteurized and Raw Milk
• Sale/Consumption of raw Milk-Position Statement, U.S. FDA Center for Food Safety and Applied Nutrition
• CDC: Highly increased risk of contracting salmonella dublin infection from raw milk
• Presentation on the safety of raw milk by the FDA
• Risks of raw milk, summary of raw milk outbreaks, University of Guelph Food Safety Network.
• "Why Raw Milk Should Be Avoided", Stephen Barrett, M.D. and "The Science and Politics of Raw Milk", by Odom Fanning