Dr. Ron Hull was one of Michael Schmidt’s expert witnesses at the recent trial and he also spoke at the International Raw Milk Symposium in Toronto on January 31, 2009. Before he left for Australia after the trial, we interviewed him for The Bovine:

Dr. Ron Hull, Ph.D., Microbiological scientist supports feasibility of safe raw milk in Ontario.

Dr. Ron Hull, Ph.D., a microbiologist from Australia, supports the feasibility of safe raw milk in Ontario.

Dr. Hull has a Ph.D in Microbiology and runs a company – Ron Hull and Associates – which does consulting work with Australian dairy producers and other food industry clients. Before starting his own business he worked for many years as a research scientist with Australia’s Commonwealth Scientific Industrial Research Organization (CSIRO), specializing in microbiology in the realm of food science, dealing with germs, bacteria, and pathogens.

Regarding the Michael Schmidt case and the feasibility of producing and marketing farm fresh unpasteurized milk, Dr. Hull states that the Crown’s own documentation shows that about 95% of Ontario’s conventional dairy farms are pathogen free. The problem arises when milk from the other five percent is mixed with the pathogen-free milk in tanker trucks and milk storage silos. Dr. Hull supports the concept that there be two types or two streams of raw milk, one produced under carefully controlled management specifically for raw consumption and another produced under the present standards, destined for pasteurization.

Dr. Hull thinks that it would be feasible to set up a food safety plan through which producers of farm-fresh unpasteurized milk would be licensed. That’s how it’s done in Europe, according to Dr. Hull. In Michigan, Dr. Ted Beals (another of Michael Schmidt’s expert witnesses) is working with a group that includes representatives from all stakeholders and has been mandated by the government to come up with workable standards and procedures for producing and marketing raw milk in the state of Michigan. While the work of this group is in progress, the state has agreed to cease harassment of cowshare operators. This process began after state crackdowns on Michigan raw milk cowshare operators in 2006 (same time as with Michael Schmidt) prompted such a flood of phone calls, faxes and emails that it shut down the operations of the state government for two days. 

As for how raw milk can be safe, Dr. Hull describes raw milk as having two systems of immunity to pathogens. The first, he calls “innate immunity”. This comprises a number of factors such as a set of enzymes, white cells (like in human blood), antimicrobial fatty acids, as well as mineral apatite complexes that also have antimicrobial activity. According to Dr. Hull, the existence and function of this innate immunity has been the subject of peer-reviewed articles in the scientific literature.

The other system of immunity to pathogens in raw milk is the existence and growth of lactic acid bacteria. These are the sort of bacteria that will cause milk to sour or turn into kefir, yogurt or cheese, if left out at room temperature.

Since both of these immune functions of milk are severely compromised by pasteurization, pasteurized milk left out at room temperature will “rot” due to the action of other types of bacteria which are not killed by pasteurization. Pasteurization kills the lactic acid bacteria, the white cells and half of the enzymes, leaving the terrain clear for the remaining bacteria types to multiply unhindered by competition.

At the Symposium, Dr. Carol Vachon, a biologist from Quebec City, showed slides of graphs comparing the growth or reduction of pathogens in cases in which the pathogens were introduced into both raw and pasteurized milk. In the case of raw milk, pathogen populations diminished over time due to the effects of the immune functions Dr. Hull describes. This was not the case with pasteurized milk, in the study quoted by Dr. Vachon.

Dr. Hull says that farm fresh unpasteurized milk produced by grass or hay-fed animals and handled appropriately can be just as safe as the pasteurized milk that Canadian consumers are accustomed to buying at the supermarket. However, lactose intolerance is more of a problem with pasteurized milk. Dr. Hull says this is because the lactic acid bacteria which aid digestion are killed during pasteurization.

Regarding the controversy around type A1 and A2 beta-casein, Dr. Hull had some interesting things to say. The research on this issue was done in New Zealand and was based on epidemiological studies of the instances of degenerate diseases such as heart disease. The short version of the story is that type A1 beta-casein is implicated in a long list of disease conditions, while type A2 is not. According to Dr. Hull, the A1 beta casein works somewhat like a hormone in its effect on the human body, in that a large dose is not needed for the effect to show up. Stories we’ve seen in the media have linked A1 beta-casein to Holstein cows, while describing Guernseys and Jerseys as giving milk which is primarily of the A2 type. Dr. Hull believes that the problem may not be specific to the Holstein breed per se, but rather to certain genetic strains which have become dominant in the Holstein cattle population due to the use of a very few high-producing bulls via artificial insemination. He believes it may take five or ten years to breed this problem out of the world’s cattle population. That would be assuming there would be a willingness to recognize the problem on the part of scientists and the political and economic will to do something about it on the part of industry and government. The A1 A2 issue is independent of raw vs pasteurized debate. And so far, awareness of the issue seems largely limited to Australia, New Zealand and Great Britain, although The Bovine has done a few stories on it. Type “A1 A2” into the search box at the top right of this page to find them.

Unlike Ontario, which has been a net importer of dairy products since 1960, Australia is a net exporter and has been exporting something in the order of 50% of the country’s dairy production. Until the year 2000, Australian farmers were protected from fluctuations in the world price by a supply management system similar to what is now called the Dairy Farmers of Ontario (formerly the Ontario Milk Marketing Board). Since then the Australian milk industry has been deregulated, with the result that about half of dairy farmer have since gone out of business. And as recently as this month, the international price for dairy products has dropped another  30%, further compromising the viability of Australia’s dairy industry. According to Dr. Hull, Australia contributes about 12% of the world’s global trade in milk while New Zealand contributes about 35%. 

On the local scene, however, Dr. Hull is quite confident that freely available farm fresh unpasteurized milk would not be stealing customers away from pasteurized. “It’s a whole new market”, he says.