What is the real meaning of the debate over “competitive exclusion” as it affects raw milk?
When last I wrote about this subject —the theory that good bacteria overwhelm bad bacteria in milk from grass-fed cows and thus protect the milk from contamination—I suggested the subject wasn’t well researched enough, and that the emotional nature of the debate over its applicability related mostly to matters of trust.
The subject had come up prominently during a day-long symposium on raw milk sponsored by the American Veterinary Medical Association (AVMA). In a consumer survey reported by Amanda Rose, a writer and raw milk drinker, respondents overwhelmingly said they believed the theory of competitive exclusion as applies to raw milk. She subsequently published a white paper (available for purchase) reviewing the literature on the subject and expressed skepticism about competitive exclusion.
A number of the symposium speakers discounted competitive exclusion in raw milk, and one, research scientist Michele Jay-Russell, presented the results of two preliminary studies of raw milk from the University of California, Davis, that seemed to contradict the theory. She concluded there was “no evidence of ‘competitive exclusion’ in either preliminary study.”
Now the Weston A. Price Foundation has published a rebuttal to Amanda Rose’s claims, written by Ted Beals, the retired Michigan pathologist who has conducted studies on lactose intolerance in raw milk and testified in a number of court cases involving producers of raw milk. The rebuttal is headed: “Does Raw Milk Kill Pathogens?
Ted says that Amanda’s “position paper gives the impression that milk can contain extremely dangerous bacteria.” He adds, “I do not disagree that milk, like all foods, can be contaminated with disease-causing microorganisms, but the inquiring public needs accurate and objective information. The opponents of raw milk have learned how best to scare people. (Amanda) Rose claims to provide balanced information, but this position paper is far from balanced; it is specifically styled to scare, not inform, the public.”
Ted goes on to suggest that “competitive exclusion” is a misleading term. “As a biologist, I prefer the phrase ‘competitive inhibition.’ He goes on to explain that competitive exclusion “relates to the interactions of living bacteria colonies in mixed communities, where certain bacteria are able to inhibit (not exclude) others from becoming established. This phenomenon is not something that can be measured in test tubs. (Amanda) Rose inappropriately applies the term competitive exclusion to the ability of raw milk to kill off pathogens inoculated into laboratory samples of raw milk.”
Amanda acknowledges on the web page with her white paper, Ted’s critique, which is also contained in an upcoming print version of the WAPF journal, observing, “His review was critical…However, he and I are interested in a similar question: what happens to pathogens in milk when there is a very small contamination event? I have asked him for such data and will update the paper accordingly.”
Ted in his assessment examines several papers that report on laboratory results, and explains how they fail to replicate real-life experiences—for example, by injecting huge doses of pathogens into milk to study outcomes.
Ted assesses a number of studies, which show varying results as to pathogen growth in milk. In the end, though, Ted seems to depart from his original premise that the lab studies are inappropriate, when he says, “That fresh raw milk has the properties to kill pathogens is no urban legend; it is proven science.”
Now, perhaps his emphasis is on the word “properties.” He starts with concerns about lab techniques, and concludes with an emphatic answer to his original question.
I know he confined his assessment to studies Amanda cited in her paper. But he had the advantage of access to the studies included in the AVMA presentations, so I found myself wondering about his failure to include the University of California, Davis, research, if only to assess its viability.
I’m not a scientist, and don’t pretend to know who is right or which research is most appropriate. I think Ted’s most convincing point is that raw milk opponents position incomplete or tentative research, to scare consumers. That is evident along a number of topics; for example, as I pointed out in my AVMA presentation, the data on the number of illnesses from raw milk isn’t in the least bit alarming, yet opponents take a few dramatic cases and focus on those instead of the actual data to further the scare claims.
Ted also does an important service in explaining the science and research techniques that underlay the studies that get tossed around by the proponents and opponents of raw milk. I applaud his paper, it makes a significant contribution in the education process. That’s really what’s needed in this long-term debate–more information and intelligent analysis.
I have contacted Ted to ask for the research he refers to.
I should note that the only reason I review the literature I do in that paper is because it is the literature cited by raw milk advocates. Since I wrote the paper I get a lot of comments along the lines of "those studies don’t mean anything anyway." That notion is at least one part of Ted’s argument — that the pathogen levels studied are so high that the conclusions are meaningless.
Here’s a suggestion to raw milk advocates who cite this literature (and I could name many): If the research isn’t meaningful, don’t cite it.
I totally agree with David’s general point that the raw milk issue should be about access and food choice and, as a result, microbiology arguments are red herrings. The problem is that these arguments are given a lot of ink (digital and real) by advocates. If they are not important, just move on.
The paper I am writing that Ted refers to in his review is a 100% ibertarian paper in favor of consumer choice. Considering Ted appears to questions my raw milk credentials in his review, I feel like I am a pair of old dusty gray shoes in a world of black and white patent leather. It may be just as well, it’s a whole lot easier to homestead in my shoes. I’m off to harvest…
Amanda
One possibly overlooked variable that I wonder about is the varying quality of raw milk used for such studies. As we know, "milk" is not necessarily just "milk", so it’s reasonable to expect a variation in immune response correlating with the quality of production methods. I’ve raised this question with Amanda and she’s told me there is no information on these studies as to the herd management practices of the farms where the test milk originated.
I wonder also whether researchers are using the latest technology that allows monitoring of small pathogen populations. While I’m not claiming any scientific credentials, here are two stories about cutting edge technologies that it would seem could be pressed into service to test for smaller amounts of bacteria — and thus obviate the need for introducing ridiculously huge amounts of pathogens in these tests:
http://thebovine.wordpress.com/2009/03/18/polymer-chain-reaction-testing-for-pathogen-dna-offers-a-new-technology-to-help-ensure-raw-milk-safety/
http://thebovine.wordpress.com/2009/05/19/new-technology-to-monitor-bacteria-bactoscan-already-in-use-at-uae-dairy/
These are issues people have been discussing on this blog for a long time now. It will be interesting to read the studies.
Amanda
http://www.panna.org/legacy/panups/panup_20020712.dv.html
"Just one mistake by a biotech company and we’ll be eating other people’s prescription drugs in our corn flakes,"
"Joe Jilka of ProdiGene, speaking of his company’s corn engineered to produce a pig vaccine (TGEV), seems more concerned about theft than public safety: "…the best way to secure it is to grow it just like any other corn. In other words, the anonymity of it just completely hides it. You know, our TGEV corn grown [sic] was up here by Story City right by the interstate, and no one could have ever seen it."
"Corn, a prolific pollinator, is the primary crop engineered to produce biopharmaceuticals and chemicals. ProdiGene, the company with the most plantings of drug and chemical-producing plants, projects that 10% of the corn crop will be devoted to biopharm production by 2010."
I know you are not necessarily addressing me directly, but if raw milk advocacy people think I’m barking up the wrong tree in reviewing the literature I review, I wonder why they cite it in the first place. I’m a social scientist. I would have never had the idea on my own that raw milk kills pathogens. I read it in raw milk literature. They cite the body of research I review.
Amanda
"Today, there is growing concern over the use of antibiotics for industrial processes. In recent years the misuse of antibiotics globally in both the medical and agriculture-agrifood industries has led to the emergence and spread of antibiotic-resistant bacteria. This may not be a problem for the fuel ethanol industry since mashes are distilled at the end and the antibiotics used are destroyed during the distillation process."
"Unfortunately, it is becoming a common practice in certain industrial operations to either underdose antibiotics when an efficient control of contamination is observed or to overdose antibiotics when the needed effect has not been observed. Underdosing antibiotics could lead to a lack of efficacy and may increase the risk of resistance development in microorganisms. Overdosing antibiotics can affect the fermentation rate of yeast and increase the chances that the distillation process does not inactivate the antibiotic used."
The Mash left over from ethanol production is used for animal feed.The purpose of the antibiotics used in ethanol production is to suppress the lactic acid bacteria which is competing with the yeast for the corn sugar.If this mash is fed to cows,will it suppress the lactic acid bacteria in the cow’s rumen and lead to more pathogens in it’s manure and milk?
Raw milk produced in the way that advocates recomend does have the "properties" or the diverse community of lactic acid bacteria that research has proven repeatedly to have the ability to inhibit "pathogens".Whether Raw milk produced in other ways can inhibit "pathogens" is not worth arguing about.If raw milk clabbers properly,if you can make good cheese out of it,then it does contain the protective LAB.The science showing that LAB does inhibit"pathogens" is not questioned.We don’t need more research on LAB’s ability to inhibit pathogens.It is the contaminants in our food that suppresses the LAB and leads to acute illness,not the raw milk.
http://hartkeisonline.com/2009/09/11/new-guide-to-raw-milk-food-safety-released/#more-3633
As for all of this nonsense with the analysis of Dr. Amanda Roses white paper, Dr. Beals never seems to get the pointraw milk bacteria cannot ensure food safety. He did a lot of blah, blah, blah, with the attempt to discredit Dr. Rose. Bottom line, the research sited is used by leaders in the raw milk movement to promote the belief that raw milk is safe. The analysis of the research is manipulated to fit their agenda. After reading Dr. Beals rebuttal, I have to wonder if he has a mail order degree. It is now quite obvious why the raw milk movement states what they do if this is their expert. It explains a lot.
Amanda is a raw milk consumer and appears to be the only person that has the courage to speak the truth. Thanks Amanda!
cp
Has there been studies that show what happens to those animals/fish, for human consumption, then results of human consumption of those products? I’ve read where some animal studies don’t look too healthy for humans, yet the product’s studies seem to stop and aren’t further investigated on humans and the products are consumed by humans.
http://www.fda.gov/Food/FoodSafety/Product-SpecificInformation/MilkSafety/ConsumerInformationAboutMilkSafety/ucm165477.htm
"Pasteurization will destroy all of the pathogens that we have mentioned thus far."
This statement is very misleading, people stop reading at the word pathogens and most people haven’t a clue about life cycles of pathogens. The govt misleads/lies often, yet they get away with it.
There are no guarantees in life. Analyzing quantitative and qualitative data demonstrates advanced research and evaluation methods. All sides would learn from it.
On pathogens in the milk, Miguel, there just isn’t evidence to support such a strong claim for all pathogens, at least I haven’t seen it. In fact, the UC Davis study underway stands in stark contrast to your claim.
CP – I appreciate your support but what we write ultimately speaks for itself. Scientific training should make our writing better but the true test is in how well the writing stands on its own. Within the next week, I’ll provide a response to Beals’ review.
I’ll post a link when the response is ready. Take care everyone.
Amanda
It has been stated by opponents of Raw milk that the infective dose of E.coli 0157:H7 is as small as 10 cells/ml.The only possible way for this to be true is if the lactic acid bacteria are inhibited, otherwise they would rapidly outnumber and control the growth of 0157:H7.Why do you always ignore the fact that 0157:H7 needs the help of a factor that inhibits the LAB in order to survive?Serious 0157:H7 infection can be successfully treated with LAB.We are not talking about 10 cells/ml but billions of cells/ml.How can this be possible if 0157:H7 is so dangerous?What does the UC davis study claim?
A guide for raw milk safety from a member of Ted Beals family is probably a welcome and well-thought-out piece of work. Ive tried to find a copy of, or a source for Margaret Beals booklet on the net. I found neither. Where did you get yours?
As regards the likely accuracy of what she says, I believe **proper attention to detail can eliminate risk of foodborne illness** is being accurate when the emphasis is placed on the word PROPER. Also, Mrs. Beals clearly referred, here, to foodborne illness and made no claim guaranteeing **pathogen free raw milk**. One does not equate to the other, and I think it is careless thinking to confuse the two.
RE: "Safe Handling – A Consumer’s Guide to Fresh Whole Unprocessed Milk" by Peggy Beals, RN
You can get these directly from Peggy. Email me off-list for her contact info …. She’s a pleasure to work with and very generous; I ordered a bunch on behalf of the Raw Milk Association of Colorado shareholders and at the end of the year she donated profits to RMAC.
-Blair
720-985-5842
info@rawmilkcolorado.org
To order copies of Safe Handling contact: Peggy Beals of the Michigan Fresh Milk Council, PO Box 762, Grass Lake, MI 49240 or email pegbeals at msn.com Price: $5.00 single copy, Bulk rates are: for 25 49, $3.50 ea for 50 99, $3.00 ea, for 100 or more, $2.50 ea.
-Blair
Miguel,
My research background is in political science. What I need from you is a a citation of a literature review from a peer review journal that can give me the overall picture of what you are describing.
I have also never argued that LAB acts against pathogens. The key question is whether it does it consistently enough and quickly enough in raw milk to assure consumer safety.
Amanda
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1201237
"Escherichia coli serotype O157:H7 causes acute diarrhea, hemorrhagic colitis, and hemolytic uremic syndrome (18). The organism is the most common serotype identified in the group of enteric pathogens variously referred to as enterohemorrhagic E. coli, verotoxin-producing E. coli, and Shiga-like toxin-producing E. coli (15). Current therapy is limited to supportive treatment alone, because the use of antibiotics appears to increase the risk of systemic complications, such as acute renal failure occurring in hemolytic uremic syndrome, perhaps by promoting the release of toxin from the periplasm (34)"
"Probiotics refer to a group of nonpathogenic organisms that are purported to have beneficial effects on health (26). A meta-analysis of randomized controlled trials provided evidence of the efficacy of lactic acid-producing bacteria for both the prevention and treatment of acute diarrhea in infants and young children (13). However, the precise mechanisms underlying these beneficial effects have not been clearly delineated. Therefore, the aims of the present study were to determine whether Lactobacillus species prevent injury to polarized intestinal T84 cell monolayers induced by infection with E. coli O157:H7 and E. coli O127:H6."
"Probiotics have also been employed with success in vivo. For example, in an infant rabbit model of E. coli O157:H7 infection, L. casei promotes immune responses against the E. coli cytotoxin and enhances the elimination of O157:H7 from the intestinal tract (23). Using a model of streptomycin-treated mice, Asahara et al. (1) showed that Bifidobacterium breve inhibits the consequences of E. coli O157:H7 infection in parallel with a drop in the luminal pH due to the production of high levels of acetic acid. Probiotics are also effective at reducing O157:H7 gut colonization in ruminants (36), which serve as the environmental reservoir for enterohemorrhagic E. coli. For humans, randomized trials have provided evidence of a beneficial effect of probiotics (20), including both the prevention and treatment of acute diarrhea in children"
http://74.125.47.132/search?q=cache:N6fqDi5W-5gJ:www.essentialformulas.com/research/OHHIRA_OCT_2000_PHD.doc+0157:H7+infection+treatment+lactic+acid+bacteria&cd=19&hl=en&ct=clnk&gl=us&client=firefox-a
http://74.125.47.132/search?q=cache:sNJh65D-D_4J:www.cazv.cz/2003/2002/vet6_02/herich.pdf+lactic+acid+bacteria+pathogens&hl=en&ct=clnk&cd=1&gl=us&client=firefox-a
This research is very interesting. For someone who had a mild case of E.coli 0157:H7, giving the person probiotics might be possible because acute cramping and diarrhea may be the only symptom.
It is not so simple for a severe case of E.coli 0157:H7. Chris diarrhea started in the morning and by the evening he had blood in his stool. This all happened in a 12 hour period of time. E.coli 0157:H7 hits hard and fast.
It took about 45 minutes to get him to the hospital. By the time we arrived the pain became so intense, he vomited with every bowel movement. He endured this routine every 15 minutes to half an hour for 5 days non-stop. It was relentless and what came out of him was not recognizable as a bowel movement.
On day 2 in the hospital, they did try giving him a pharmaceutical grade probiotic in applesauce. It was an impossible task. He vomited within 1 minute. Ingesting this small amount of food then triggered intense pain in his stomach. The Shiga toxins were already attacking his pancreas. This was two days prior to being given the antibiotics. Signs of pre-HUS were already there.
Everything in theory sounds so easyjust give probiotics. But the reality for someone with a severe case of E.coli 0157:H7 is far different story.
On a side note, once HUS set in, we did have alternative doctors (both prominent M.D.s in the world of autism) consulting with the Kaiser doctors. There was talk of using charcoal to sop up the toxins in the intestinal track, but that was too risky in the event it proliferated his colon. An extremely high dose of vitamin A was also discussed. It would have to be given through his I.V. The Kaiser doctors were not comfortable with this. We did end of applying a topical dose of a product called Ambrotose 3 to 4 times a day. It is a glyconutrient.
Once you find your child in the life and death situation of HUS, supportive care is all there is. It is an amazing chemistry act. The red blood cells begin to die, so blood transfusions are done. The plasma isnt right, plasma transfusions are done. Food cant be ingested, so TPN is used. The kidneys shut down and kidney dialysis begins. When congestive heart failure sets in, a ventilator takes over for the breathing. We didnt experience this, but some require their colons to be partially or completely removed. It is a journey to hell and all one can do is wait to see if the body can rebound after the Shiga toxins die off. Takes about 10 days; a very long ten days.
Mary McGonigle-Martin
I was responding to Amanda’s request for research that supports my statement that LAB does not only prevent infection with 0157:H7 but it also can be used to treat it.I agree, treating diarrhea and vomiting orally is almost impossible.It might be possible if the probiotic was taken at the very first signs of illness and continuously in small amounts throughout the illness.Prevention is a better approach.If you look back at what chris ate or did before he became ill you might be able to identify what it was that neutralized or inhibited the LAB in his gut .This is what caused the illness.
Example: this past july our neighbor had a very serious acute illness.The hog confinement building on the farm to the east of them had just emptied their liquid manure on to a field bordering our neighbor’s farm.The wind blew from the east.She worked outside all day threshing oats.It was hot.It is very hard work. Everyone felt nauseous from breathing the foul air.No one got sick but her.We puzzeled over the reason for the illness.Then we asked her if she had taken antibiotics lately.She had,for a tooth infection.Breathing air filled with antibiotic resistant bacteria had not made anyone else acutely ill,but taking antibiotics at the same time was enough to nearly kill her.
If you search for a factor that suppressed Chris’s normally protective bacteria I am sure you will find something.Without this factor,his normal bacteria would have been able to keep him from getting so sick.
I don’t see enough evidence there to support the larger claim you are making. If you do find a review that connects all the dots, post it.What I see is one variable among many in a complex system. As a parent, I appreciate the role of probiotics but I also know I can’t protect my children from the many attacks on their health everyday. Because of that, I’d like them to eat food without crap in it.
Amanda