Thursday, March 26, 2009

Raw Milk - Will it really make me sick?

I know that I've been slacking the last few weeks. When I began this blog, I swore up and down that I'd post every two nights, but I got to feeling like that was too frequent. I was wearing out my four readers with the overload of fascinating information I was pulling together. So I decided to go down to three. That worked for a few weeks... But, you see, I have a lot going on right now, and this week I actually went four days without posting (gasp!) SO... hoping to recapture my lost reader, I'm going for the gusto, I'm finally going to resume discussing my agonizing dilemma over whether or not to get a raw milk share (see Where to Start Looking for Raw Milk).

Why, you might ask, did I wait so long? I do have a good excuse. There is so much information out there on this topic, that I couldn't figure out how to assemble it. I've read presentations, infectious disease articles, FDA warnings, watched California senate debates, and after all of this, I still can't make my mind up.

But I do feel that I've boiled it down to a few key questions...

Does raw milk carry more dangerous pathogens than pasteurized milk?

How this question has been answered is actually quite interesting in itself. The pro-raw milk articles I've read point out that in the numerous tests that have been done comparing pathogen levels of raw and pasteurized milk, the milk is usually compared from the same source.

In fact, in one study, the cows' udders were injected with bacteria to see if the bacteria was passed into the milk, which it was (shoot, sorry, I can't find my reference on this - but I know I read it somewhere). This sounds like a logical test, except that it only tells us one thing - milk with a high pathogen level will have a reduced pathogen level after pasteurization.

What if the pathogen level of the milk isn't high to begin with? What I'm getting at is, have any studies been done examining the pathogen levels of milk from pastured, grass fed cows? None that I could find, unfortunately. I am trying to be unbiased here, but I do strongly believe that cows raised on grass and fresh air are going to be infinitely healthier than industrial dairy cows crammed together in a building eating corn meal and antibiotics. Healthier cows probably produce cleaner milk. For instance, "Vitamin E and selenium improve immune cell function and allow proper closing of the streak canal after milking, the canal through which pathogens generally infect the mammary gland ... Vitamin E intakes of lactating cows on pasture can be four to five times higher than the average intake in the United States"^

If the cow tested in the previously mentioned study is a healthy pastured cow that does indeed deliver infected milk after her udder is injected with bacteria, but is otherwise uninfected, what does the study prove?

A more relevant study would probably be to test the infection rates of raw milk in pastured cows.

A follow-up question I have is how clean does pasteurized milk stay after pasteurization? I'm curious as to whether killing off all bacteria in milk is really a good thing - couldn't we be creating the perfect environment in which bacteria that survives pasteurization or finds its way into the milk could thrive, similar to the Superbug effect that the overuse of antibiotics has caused in humans? Statistics on rates of disease caused by pasteurized versus raw milk would probably help answer this question. So...

Is the risk of getting sick higher with raw or pasteurized milk?

Here are some interesting statistics from the Weston A. Price article, RESPONSE TO ANTI-RAW MILK ARTICLE Published in Clinical Infectious Diseases, January 2009

Statistics from the FDA attribute a 25 fold decrease in the % of foodborne illnesses due to milk since 1938 to pasteurization, but the source of the improvement cannot be isolated as states adopted many other cleanliness standards at the same time as they adopted the pasteurization standard.

"Although there were fewer outbreaks attributed to pasteurized milk than to raw milk between 1980 and 2005 (the years for which the CDC has data available in both categories), those outbreaks attributed to pasteurized milk were larger, and there were therefore nearly eleven times as many illnesses attributed to pasteurized milk as there were to raw milk."

"According to certified information the CDC has provided to us, between 1980 and 2005 there were 41 documented outbreaks attributing 19,531 illnesses to the consumption of pasteurized milk and milk products."

These numbers bring up a strong point in favor of eating local milk, pasteurized or not. Listening to the news the last few years, I can think of so many stories related to massive disease outbreaks attributed to one initial source: spinach, tomatoes, peanuts. These infections were probably not widespread to start with, but there seems to be so much consolidation in the food industry that a small outbreak can reach many, many people. This phenomenon would explain why even if pasteurized milk is safer than raw milk, the fact that it is usually produced on a large scale by industrial dairies means that it has the potential to infect many, many more people. A local dairy has a much smaller sphere of influence.

I felt that The Infectious Diseases article being rebuked by the stats just above, Unpasteurized Milk: A Continued Public Health Threat, did not seem very objective. It seemed to me to throw out common raw milk scare tactics, salmonella, E. Coli, Listeria, without discussing them in very scientific terms. Here is an example of one study:

"An overwhelming majority of dairy producers feel responsible for the safety and wholesomeness of the food products that leave their farms. Good animal health and hygienic conditions on the farm are important for the welfare of the animals and the profitability of the producers, as well as for the quality and wholesomeness of the raw food products leaving the farms for human consumption. Nevertheless, many dairy producers are unaware of the zoonotic potential of the most common bacterial contaminants in milk. In a recent mail‐based survey of 461 Ohio dairy farm respondants, 36% did not think Salmonella species caused disease in humans. Likewise, 81%, 88%, and 91% of farmers indicated that Listeria, Cryptosporidium, and Campylobacter species, respectively, were not associated with disease in humans (J.T.L., unpublished data)."

I'm sorry, but I do not find that to be a particularly compelling statistic. I can see why we would like a dairy farmer to understand the link between food poisoning and the hygiene standards he or she follows, but I'd bet there are plenty of passionate, humane, clean dairy farmers that don't.

I have primarily referenced two articles above, but I did read a few more, and felt that the two sides of the argument were roughly the same.

To me the core of the debate seems to be this
  • Pasteurized milk probably does kill some dangerous bacteria. Does this benefit last until the milk reaches your table, or is there potential for subsequent infection due to the now nearly sterile environment created by pasteurization?
  • Has pasteurization actually made milk safer, or is it just part of a general improvement in industrial dairy cleanliness standards?
  • Is milk from cows raised on pasture safer than milk from industrial cows, regardless of pasteurization?
  • If raw milk has a higher potential for infection, but pasteurized milk infections reach more people, from a statistical point of view, which one is really safer?
Given the one-sidedness of the articles I read, I don't feel like any of these questions were truly addressed. I've come away from this feeling like it's a complex question that every person has the right to answer for themselves.

For my part, I've made up my mind that if I am to drink raw milk, it will have to come from cows that are 100% grass fed and free range. I believe this gives me the best chance of avoiding the higher infection risk of raw milk, if indeed there is one. This means that I'll probably need to check it out myself to be sure.

Next question,

Is raw milk more nutritionally complete than pasteurized milk?

Phew, more on this another time.

4 Responses:

Robert said...

Why do you want to drink raw milk? Is it because it's just less refined, and you want to consume that type of food? Or is is better for you? Just wondering.

boulderhomecook said...

That's a good question. I got interested in raw milk because when I started looking for milk from pastured cows (100% grass fed, free range), I realized that most pastured milk in this area is raw. This got me interested in the topic. Why is raw milk gaining in popularity? Is pasteurization really necessary if the milk is processed under sanitary conditions? Is raw milk more nutritional? So it's not that I want to drink raw milk particularly, but my desire to drink pastured, locally produced milk got me interested in this topic, which I am now exploring in this blog.

Mindy said...

My husband and I have been using raw milk for 3-4 years now. I first became interested in the idea because I'm allergic to milk and heard that some people with dairy allergies can drink unpasteurized milk. After much research and reading The Untold Story of Milk by Ron Schmid, we decided to go for it. I didn't react nearly as much to unpasteurized milk, but did eventually have to give it up after 6 months or so. My husband really enjoys it and notices his allergies aren't as bad. I've now switched to raw goat's milk without a problem. I'd highly recommend it.

boulderhomecook said...

Hi Mindy,
Thanks for the advice. I'll definitely be interested in checking out both the Ron Schmid book and tasting raw goat's milk. I've continued to find quite a bit of interesting info on raw milk. I'll probably do one more post in the coming week discussing some great articles I found on Salon and Harper's about exactly the reasons you decided to try it - allergies etc. Thanks for reading.