by George Looby, DVM
Food products of all kinds tend to promote strong opinions among consumer groups as to the merits of their particular favorites. For many years there has been a ongoing discussion among those who advocate the consumption of raw milk versus pasteurized. Milk has often been described as nature’s most perfect food and certainly its balance of essential nutrients does much to justify that claim.
Those consumers who advocate raw milk feel very strongly that milk from local dairies produced by cows who have access to grass on a seasonal basis is superior to that which has been processed by pasteurization. Pasteurized milk is not a sterile product but rather the offshoot of a process developed by Louis Pasteur to counteract bacterial spoilage in wine. Pasteur found that he could use the same technology to prevent undesirable bacterial growth in milk, in particular the TB organism M. tuberculosis. TB had long been a scourge in both the human and cattle populations and to develop a process whereby the human population was put at far less risk was a monumental breakthrough.
Public Health as an organized federal agency was in the very early years of its development when it made the pasteurization of milk one of its primary focal points. Very soon it was made mandatory in many communities throughout the country.
Over the past 40 years there has been a move among some consumer groups to select foods that more closely meet their personal preferences and among these have been advocates for raw milk. Raw milk advocates maintain that certain enzymes that aid in the metabolism of calcium and phosphorus are destroyed during pasteurization. It is also claimed that certain beneficial bacteria are also destroyed during the process, some of which act as digestive aids and help regulate certain metabolic functions.
Other detrimental effects of pasteurization suggested by raw milk advocates includes the destruction of Vitamins B6 and B12 and a significant reduction in the amount of Vitamin C. It is further contended that milk from grass fed cows contains higher levels of Vitamins A and D as well as more of the omega-3 fatty acids. Raw milk contains three enzymes which are destroyed by pasteurization: phosphatase, which aids in the absorption of calcium; lipase, which aids in the digestion of fat; and lactase, which aids in the digestion of lactose.
The Federal Regulatory Agency overseeing the milk industry has, for almost 90 years, made pasteurization one of its most important objectives. The responsibility for developing and distributing this policy falls to the Public Health Service/FDA within the Department of Health and Human Services. The document which outlines the details of this oversight is the Grade A Milk Pasteurized Milk Ordinance. With the exception of milk and milk products involved in interstate commerce, it is not a legal document but rather one developed to assist state and local governments in the development of milk regulations within their respective states. This detailed document was not developed by the staff of the FDA alone but was the result of input from a wide variety of sources including industry, state and local regulatory staff and a host of others.
From the onset, it was neither the intent or purpose of these guidelines to address the nutritional side of the milk question. They were developed to insure the quality and safety of milk and milk products. In 1938 milkborne outbreaks in this country constituted 25 percent of all disease outbreaks due to infected foods and contaminated water. Today that figure stands at less than 1 percent of such reported outbreaks.
In an effort to discredit some of the claims made by raw milk advocates, the FDA has reviewed the literature regarding many of these claims and summarized their findings in an effort to insure that both sides get a fair review of their positions.
Calcium is the most plentiful and important mineral in milk and there is no reported scientific evidence that pasteurization in any way affects the absorption of calcium or its availability for any or all bodily functions in which it plays an important role.
Numerous controlled studies have shown that the proteins in milk — mainly casein and whey proteins — are unaffected by pasteurization, as is milk fat. Vitamin C is the only vitamin found in milk that is affected by pasteurization and, given that milk is not considered an important source of that vitamin, this loss is not considered significant.
It is true that certain beneficial bacteria are destroyed by pasteurization, but when this is weighed against the destruction of those that are potentially harmful, the regulatory officials view this as a weak argument. The potential exists for a number of human pathogens to be found in raw milk, most of which are quickly recognized by consumers who pay careful attention to information regarding food safety. Listeria, E. coli, Salmonella, Strep. sp., Staph sp., and Coxiella burnetti to name a few all of which can be found in the farm environment and if good sanitation is compromised in any way, they stand ready to contaminate the milk supply.
The incidence of the outbreaks of illness due to the consumption of raw milk products is high when one considers the low volume of raw milk consumed in this country when compared to the total amount of milk consumed (less than 1 percent of the total consumed). The FDA compiled a list of reported outbreaks that occurred in this country from 1987 to 2010 due to the consumption of raw milk and raw milk products and found that there were 133 outbreaks reported. These outbreaks caused 2,659 cases of illness, 269 hospitalizations, three deaths, six stillbirths and two miscarriages. It is likely that these numbers were higher due to underreporting.
Most consumers, given the choice, would prefer the food they consume be subjected to as little processing as possible, which accounts in part for the rather remarkable growth of the locally grown movement throughout the country. For many foods, this is critical in maintaining that products full nutritional value. In the case of milk, there maintains a large body of evidence against the consumption of raw milk. In the end, it comes down to consumer choice.