Raw milk movement in the United States

The raw milk movement in the United States refers to advocacy and activism for the consumption of raw milk (unpasteurized and unhomogenized) over pasteurized milk. Raw milk makes up a small proportion of the milk consumption of the American general population. 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

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 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 hormones 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

Pasteurization is a sanitation process in which milk is heated briefly to a temperature high enough to kill pathogens, followed by rapid cooling. While different times and temperatures may be used by different processors, pasteurization is most commonly achieved with heating to 161 degrees Fahrenheit (71.7 degrees Celsius) 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 (Mycobacterium bovis), listeriosis (Listeria monocytogenes), Q fever (Coxiella burnetii), brucellosis (Brucella), campylobacteriosis (Campylobacter), salmonellosis (Salmonella), and several other foodborne illnesses (e.g., Escherichia coli O157:H7). Pasteurization may not kill some resistant bacteria, which can 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 raw milk has benefits associated with superior taste, nutritional qualities and certain health benefits over pasteurized milk. A 2009 systematic review of the food safety of raw 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".

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. In addition, milk at the time was a big component of infant diets, meaning contaminated milk contributed notably to infant mortality rates. 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. Some milk producers also add additives or dilute their milk to mask contamination. 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.

Legal status of unpasteurized milk

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