Last month the long-running case of an Ontario farmer who operates a raw milk co-op was laid to rest. The judge determined that the manner in which Michael Schmidt operated his co-op, via “cow-sharing”, was not illegal. Canada’s Food and Drug Regulations and Ontario’s Health Protection and Promotion Act prohibit the sale or distribution of any animal’s milk that has not been pasteurized. However, there are no regulations against consuming raw milk. If you’re anything like me, you might wonder why anyone would want to consume raw milk at all.
Pasteurization is the process of heating milk to a specific temperature for a specific amount of time in order to destroy bacteria and make it safe for human consumption. But many raw milk proponents claim that milk is healthier before being pasteurized. In fact, it is common for raw milk proponents to refer to it as “real milk”. This suggests that pasteurized milk is somehow fake or a poor substitute for the “natural” product.
This appeal to nature may have the effect of glossing over certain facts. A recent review on the subject states that, while raw milk advocates claim that it has a greater nutritional value, tastes better, and has specific health benefits, “[s]cience-based data to substantiate these claims are limited or lacking.” The article states that there have been twelve documented disease outbreaks from 2000 to 2008 related to the consumption of unpasteurized milk in the United States. On the other hand, there were two outbreaks associated with the consumption of pasteurized milk, and in both cases it seems that the milk was contaminated after the pasteurization process (for information on illness outbreaks in Ontario related to unpasteurized milk, see here).
Raw milk proponents share many similarities with the raw food movement in general. It seems that appealing to nature is central to the raw foods ideology and some of the beliefs advocated by raw food proponents include:
- Heating food (in the case of milk, the pasteurization process) degrades and destroys enzymes needed for digestion.
- The nutrient value in raw foods is higher than those that have been heated.
- Cooked foods can cause disease.
Firstly, while it is true that enzymes can be destroyed by heat, the plant enzymes highlighted by raw food dieters are not needed for digestion. Plant enzymes are used by plants. Human digestive enzymes are produced by the body and do their work while you eat and while your body digests your food. While pasteurization of milk will destroy some enzymes, our bodies don’t use those (animal) enzymes to metabolize calcium and other nutrients. Moreover, John Sheehan from the United States Food and Drug Administration (FDA) has stated that most of the enzymes in milk that are thought to have natural antimicrobial properties tend to survive the pasteurization process.
Raw foods are not necessarily more nutritious than their cooked counterparts either. Like most things, it simply depends on the situation (i.e., type of food), so it would be hard to generalize one way or the other. For example, a 2002 study found that cooking carrots increases their level of beta-carotene (an antioxidant converted by the body into vitamin A). On the other hand, cooking can destroy the vitamin C in many vegetables. So, it depends. We have such a variety of food available to us in the Western world that one way or the other we probably make up for any ups and downs caused by cooking. And despite the claims of raw milk proponents, the FDA in the United States says that there is “no meaningful difference between the nutrient content of pasteurized and unpasteurized milk.”
Raw food advocates also make the claim that cooking food actually causes disease. Again, generalization in this manner is irresponsible — there is evidence that baking or deep-frying can result in the creation of acrylamide, a chemical that has been seen to cause cancer in experimental animals. Acrylamide is formed when a natural amino acid called asparagine reacts with naturally occurring sugars like glucose. The temperature has to be sufficiently high, but this can vary depending on the food and method of cooking.
Exposure to acrylamide has been identified as a potential concern by the Joint FAO/WHO Expert Committee on Food Additives, but the risks to humans are unclear right now. Health Canada is currently looking into adding the enzyme asparaginase to certain foods to break down the asparagine and thereby reduce the formation of acrylamide. It should be noted that it is the browning of foods by baking, frying, or deep-frying that is in question — boiling and cooking at low temperatures does not seem to have the same affect. The worst offenders are what we would typically describe as junk food (like potato chips and French fries) and should be eaten in moderation anyway.
Raw milk proponents also make claims about illness, specifically that pasteurized milk can cause lactose intolerance and allergic reactions. These claims are described as untrue by the FDA. Lactose and milk proteins are found in both raw and pasteurized milk, so any allergies or intolerance would be seen from drinking either type.
Clearly, the topic of food preparation and its impact on health and nutrition is complex and depends on many factors. Heating and cooking food has many advantages: it aids digestion so that our bodies do not have to expend a lot of energy, it softens food that our jaws and stomachs may otherwise not be able to handle, and perhaps most importantly it can eliminate harmful bacteria. Not to mention we may have been cooking for almost 2 million years! The generalizations advocated by raw food and raw milk activists should be examined with a skeptical eye rather than taken at face value.