Louis Pasteur must be rolling over in his grave. As you probably remember from your high school Biology class, he was the Frenchman who invented a method of preserving food and drink by submitting them to a specific temperature for a specific amount of time and then cooling them off rapidly. Prior to the days of pasteurization, drinking milk could make you very sick, or in some cases, prove fatal. Fast forward to 2011 and a debate is raging in some circles over the supposed health benefits of raw milk vs the pasteurized form. Read on to find out the raw truth about raw milk.
For starters, exactly what are we talking about here? Just what is raw milk? It is simply milk from cows, goats, sheep, or other animals that has not been pasteurized. It is estimated that less than 1% of all milk sold in the US is sold raw. OK, so how bad can it be? What are the dangers of drinking raw milk? Raw milk can harbor large amounts of pathogenic organisms that can lead to sickness, or in some cases, death. It can be particularly dangerous to the very young, the very old and the immunocompromised. A partial list of potential pathogens is as follows: bacteria such as Brucella, Camplyobacter, Listeria, Mycobacterium bovis, Salmonella and shiga toxin producing E. coli., parasites such as Giardia and viruses such as the norovirus.
How does the milk become contaminated? Does it come out of the animal with all this stuff in it? Some of the contamination comes from the environment in the form of feces, dirt or unsanitary processing equipment. Some of it can come from insects, rodents or other animal vectors. Other sources of contamination can be bacteria that live on the skin of the animal or infection of the udders (mastitis). Cross contamination from humans is possible from clothing or boots.
All of this may have you wondering why people are rushing in record numbers to buy raw milk. This is despite the fact that it is illegal to buy in several states in the US and can only be sold as pet food in some others. Retail sales of raw milk are only legal in 10 states. See here.
In the European Union, all raw milk products are legal and considered safe for human consumption. The individual countries are free to add certain requirements, such as special sanitary regulations, and frequent quality tests are mandatory. The sale of raw milk for drinking purposes is illegal in all states and territories in Australia.
Raw milk advocates claim that that the unpasteurized stuff contains natural enzymes and beneficial bacteria that are removed during the pasteurization process. They also often claim that it just tastes better. A website by the name of Raw Milk Truth offers these anecdotes:
“A lovely lady and her family stopped by on their way passing through town. She had been drinking raw milk for years and her chronic arthritis had disappeared. However, on her recent 3-month vacation she had not been able to find any farms nearby where she could buy raw milk. During that time her arthritis came back full force. She related this story to me when she stopped by our farm to pick up some raw milk on her way back home.
Another case in point is a woman who had been trying to get pregnant for years and having no luck. She became pregnant 6 months after beginning to drink raw milk.”
Please feel free to judge the merits of these statements for yourselves without further comment from me.
One of the health claims of raw milk is that it contains more enzymes and nutrients than pasteurized milk. This is true. The process that makes the milk safer to drink also inactivates certain enzymes and nutrients. Before I go on, I’d like to note that enzymes in milk do not make a major contribution to the digestion of milk in humans. That is accomplished by enzymes in the stomach and small intestine.
Lipases are enzymes that degrade fats. The major lipase in milk is lipoprotein lipase. Pasteurization will inactivate the lipase in milk and increase its shelf life. Proteases are enzymes that degrade proteins. Certain proteases are inactivated by heat and others are not. Protein degradation may be undesirable in that it may result in bitter or off flavors in the milk. Lactoperoxidase is one of the most heat stable enzymes found in milk. It has been suggested that the presence of lactoperoxidase in raw milk inhibits pathogen growth. However, since lactoperoxidase only has antimicrobial properties when combined with hydrogen peroxide and thiocyanate, these chemicals would have to be added to milk to show any of that type of benefit.
Some nutrients, such as vitamins B and C, are somewhat destroyed by the pasteurization process. However, a typical healthy diet contains more than enough of these nutrients to make up the difference. Vitamins D, K and E are not altered by pasteurization.
So, what have we learned? There is no doubt that drinking pasteurized milk is healthful for most people. It is full of is full of calcium, vitamin D, phosphorous and a balance of other nutrients that have been proven to build your bones and teeth as well as promote the healthy function of your muscles and blood vessels. There is also no doubt that it is very possible for raw milk to be contaminated with pathogens that can make you very ill. You can’t look at, smell, or taste a bottle of raw milk and tell if it’s safe to drink. Please consider these facts before you play Russian roulette with your health.