Archive for the ‘Controversial Science’ Category

The death of a Victorian toddler du to the consumption of ‘raw’ milk has put this issue / debate / controversy in the spotlight.

Article in The Age

Article in The Conversation

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A well written critique of the controversy surround raw milk I discovered while researching for a class essay is the article – “Bacteria Land”: The Battle over Raw Milk by Anne Mendelson and published in Gastronomica: The Journal of Food and Culture in 2011. Mendelson’s article details the extensive debate around pasteurisation and raw milk that raged at the end of the 19th century and at the beginning of the 20th century. She also gives a pithy critique of the ‘raw’ milk debate now. Well worth a read.

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As part of the final assessment for my science communication class on controversial science, we had to write an essay about our chosen controversy, and, discuss communication issues and how the controversy may be resolved. Below are some excerpts from May essay discussing some of the communication actions the anti-‘raw’ milk faction (primarily governments and public health agencies) could take to help bridge between the two sides perhaps help resolve the controversy.

Communication and associated issues play a key role in the raw milk debate and have helped perpetuate it. An open dialogue between the two opposing sides may help resolve some of these issues. A number of the issues that have exasperated the raw milk debate are associated with communications from government and public health agencies. These agencies could undertake a number of actions to acknowledge and engage with pro-raw milk representatives, such as acknowledgement of different and is similar values and public forums, and these are summarised in the table below. Educational and science communication actions may also assist with bridging the gap between the opposing sides and providing information that is easily understandable by all stakeholders involved.

Suggested Actions for Governments & Public Health Agencies

  • Acknowledge that people consume raw milk and will consume raw milk regardless of public health messages and legal status.
      – Provide information to potential and current raw milk consumers regarding proper handling and storage.
      – Promote safe and hygienic milking, handling and storage techniques to farmers and consumers
  • Acknowledge differences in beliefs between pro- and anti- raw milk sides
  • Acknowledge desire to support local farmers and communities and other ways of doing this
  • Acknowledge and understand differences in perception of risk between the two sides
  • Acknowledge that both sides are concerned with human health and healthy eating
  • Engagement & Dialogue

  • Conduct public forums, discussions and call for submissions from consumers, advocates, scientific, public health and agricultural experts, farmers and legislators
  • Openly discuss –
    standards/guidelines and/or regulation of raw milk processing
    different methods of pasteurisation and alternatives to pasteurisation, including advantages and disadvantages of each methods
    assisting raw milk producers to comply with regulations (Schutz and Ferree, 2012)
  • Engage with key stakeholders and organisations in debates
  • Engage with individual consumers
  • Education

  • Clearly explain the regulatory issues involved in regulating raw milk
  • Explain (in appropriate language with examples that a lay audience can understand) reasons for discouraging the consumption of raw milk, including –
    food-borne diseases and symptoms
    regulatory issues and obligations and to ensure food safety and protect citizens
    pasteurisation as standard practise
  • Science Communication

  • Use science communication methods to discuss and disseminate –
      – results and conclusions from research and epidemiological studies regarding food-borne illness and raw milk
      – results from immunological and biochemical studies in relation to health benefit claims and effects of pasteurisation on milk
  • Will we see this implemented? Will governments and public health agencies open a dialogue and listen to all the stakeholders in the ‘raw’ milk debate?

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    Source - Wikimedia. Licensed under Creative Commons

    Source – Wikimedia. Licensed under Creative Commons

    In my initial reading on the controversial science topic of ‘raw’ milk (debate, consumption, movement), the risk of contracting food-borne pathogenic bacteria featured prominently. In one of my first posts on the ‘raw’ milk controversy – Raw Milk & Pasteurisation, I posed a few questions that I wished to answer. Until now I haven’t delved too deep into these questions (I briefly touched on the risk of contracting a food-borne illness from consuming ‘raw’ milk in my post – Risk Assessment of ‘Raw’ Cow Milk in Australia last week). These unanswered questions are –

    • If ‘raw’ milk is unpasteurised, are pathogenic bacteria such as Campylobacter jejuni, Salmonella species and Escherichia coli (E. coli) present in ‘raw’ milk?
    • And what risk does drinking ‘raw’ milk pose?
    • Are you likely to suffer food poisoning from drinking ‘raw’ milk?

    Pathogenic bacteria isolated from ‘raw’ milk may include Salmonella species Campylobacter species, Listeria monocytogenes and E.coli, aetiological agents of gastroenteritis and more serious complications such Haemolytic Uremic Syndrome (which can lead to kidney failure) and Guillian-Barre Syndrome (a form of flaccid paralysis) (CDC, 2014a and Foodsafety.gov).

    The Centers of Disease Control (2014) states that individuals are 150 more times likely to contract a food-borne illness from ‘raw’ milk than pasteurised milk. Unpasteurised milk results in 13 times more hospitalisations than illnesses involving pasteurised dairy products.

    In a epidemiological study of disease outbreaks contracted from unpasteurised dairy products from 1993 to 2006 (Nonpasteurised Dairy Products, Disease Outbreaks, and State Laws – United States, 1993 – 2006), the CDC reported that of 121 outbreaks due to dairy products reported to the CDC, 73 (60%) outbreaks were caused by ‘raw’ milk (CDC, 2014b). To directly quote the CDC –

    “Probably no more than 1% of the milk consumed in the United States is raw, yet more outbreaks were caused by raw milk than by pasteurised milk. If you consider the number of outbreaks caused by raw milk in light of the very small amount of milk that is consumed raw, the risk of outbreaks caused by raw milk is at least 150 times greater than the risk of outbreaks caused by pasteurised milk.”

    The CDC also reported in this article that the hospitalisation rate for patients in outbreaks caused by raw milk was 13 times higher (13% vs. 1%) than the rate for people in outbreaks caused by pasteurised milk, likely due to outbreaks from ‘raw’ milk being caused by bacteria that cause more severe illnesses, such as E. coli o157:H7 (CDC, 2014b).

    As a follow on from the CDC report described above, James Andrews at Food Safety News reported in 2012 that – “Since January 2007, the end of the study’s review window, there have been at least 56 additional food-borne illness outbreaks associated with raw milk. Between 2010 and 2011, raw dairy products were linked to 21 outbreaks and 201 illnesses, while pasteurised dairy products caused two outbreaks and 39 illnesses.”

    ‘Raw’ dairy products are linked to more food-borne illness outbreaks than pasteurised dairy products. And only a small proportion of the United States population consumes ‘raw’ dairy products. How do the numbers of food-borne illness outbreaks linked to dairy products (pasteurised and unpasteurised) compare to those caused by other food sources such as poultry, beef, shellfish and vegetables?

    A CDC report on food-borne disease outbreaks in the United States from 1998 to 2008 by Gould et al, 2013 (Surveillance for Foodborne Disease Outbreaks — United States, 1998–2008, summarised on the Surveillance for Foodborne Disease Outbreaks – United States, 1998-2008 webpage) reported that the most common commodities implicated in food-borne illness outbreaks for which a food vehicle could be assigned (3,264 outbreaks) were poultry (19%), fish (19%) and beef (12%). Dairy products (presumably pasteurised and unpasteurised (‘raw’) dairy products) were implicated in about 6% of outbreaks (Gould et al, 2013). The percentage of outbreaks associated with dairy products increased from 4% of outbreaks in 1998 – 1999 to 7% during 2006 – 2008 (CDC, 2013). Interestingly, the CDC states that the increase in the number of outbreaks caused by dairy products is due to an increase in the number of outbreaks caused by unpasteurised (‘raw’) milk (CDC, 2013).

    The CDC, on the website summarising the surveillance report,  reports states that “leafy vegetables, poultry, beef, and foods in the category that contains fruits and nuts were responsible for the most outbreak-associated illnesses.” In the surveillance report itself, Gould et al state that dairy products (and other food commodities such as fruits/nuts and vine-stalk vegetables) contribute to a relatively larger percentage of illnesses than outbreaks, and based on the percentage of outbreak-related illnesses associated with each commodity, analysis attributed the majority of foodborne illnesses to leafy vegetables, dairy, fruits/nuts, and poultry.

    In conclusion, according to CDC statistics, someone is a lot more likely to contract a food-borne illness (caused by pathogenic bacteria such as E. coli, Campylobacter or Salmonella species) from unpasteurised (‘raw’) dairy products, than pasteurised dairy products.

    Dear readers, would you drink ‘raw’ milk given these statistics?


    Andrews, James (2012). CDC: Raw Milk Much More Likely to Cause Illness. Food Safety News. Retrieved 26 October 2014 from http://www.foodsafetynews.com/2012/02/cdc-raw-milk-much-more-likely-to-cause-illness/#.VExl4r7N78s

    Centers for Disease Control. (2013). Surveillance for Foodborne Disease Outbreaks – United States, 1998-2008. Retrieved 26 October 2014 from http://www.cdc.gov/foodsafety/fdoss/data/annual-summaries/mmwr-questions-and-answers-1998-2008.html

    CDC report summarised by CDC 2013 – Gould, L. H., Walsh, K. A., Vieira, A. R., Herman, K., Williams, I. T., Hall, A. J. & Cole, D. (2013). Surveillance for Foodborne Disease Outbreaks — United States, 1998–2008. Surveillance Summaries. 62(SS01), 1-34. Retrieved 26 October 2014 from http://www.cdc.gov/mmwr/preview/mmwrhtml/ss6202a1.htm?s_cid=ss6202a1_w

    Centers for Disease Control. (2014a). Raw Milk Questions and Answers. Retrieved 21 August 2014 from http://www.cdc.gov/foodsafety/rawmilk/raw-milk-questions-and-answers.html,

    Centers for Disease Control. (2014b). Nonpasteurized Disease Outbreaks, 1993-2006. Retrieved 26 October 2014 from http://www.cdc.gov/foodsafety/rawmilk/nonpasteurized-outbreaks.html

    CDC Report – summarised by CDC, 2014b – Langer, A. J., Ayers, T., Grass, J., Lynch, M., Angulo, F. J. and Mahon, B. E. (2012) Nonpasteurized Dairy Products, Disease Outbreaks, and State Laws—United States, 1993–2006. Emerging Infectious Diseases 18(3). 386 – 391. retrieved 26 October 2014 from http://wwwnc.cdc.gov/eid/article/18/3/pdfs/11-1370.pdf
    Foodsafety.gov – Milk, Cheese, and Dairy Products – Myths About Raw Milk. Retrieved 26 October 2014 from http://www.foodsafety.gov/keep/types/milk/index.html

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    In my post The ‘Raw’ Milk Controversy from September I touched the key elements involved in the controversy around ‘raw’ milk. One element in the controversy that I haven’t discussed so far is –

    Industry – Animal Husbandry & Food Manufacturing 

    • Modern animal husbandry and dairy-farming practises
    • Mass production and increased risk of contamination of animal products
    • Pasteurisation as standard practise in the dairy industry
    • An industry driven by greed and profit VS organic farming techniques; small-scale farming with better conditions for dairy cattle; more traditional methods; and support for local farmers

    I’m not qualified nor very knowledgeable on dairy-farming or milk processing techniques, but I have been wondering if the following may have changed the taste, quality and safety of milk, and thus influence consumers to seek out ‘raw’ milk for consumption –

    • Modern dairy-farming and animal husbandry practises
      • Certain breeds of cows (milk sourced from only a few breeds)
      • Cows being grain fed
      • Use of antibiotics and prophylactics
      • The rise of pathogenic strains of bacterial species such as E. coli 0157:H7
    • Modern milk processing practises
      • Mixing of milk from multiple herds
      • Pasteurisation
      • Homogenisation
      • Fortification

    And do the following choices / options also influence consumers –

    • Non-organic VS organic milk
    • Confined VS free range dairy cattle
    • Milk mixed from multiple dairy herds VS milk from a single herd
    • Homogenised VS non-homogenised
    • Milk sourced from more traditional breeds of cow

    Discussions around traditional breeds, milk from single herds, and a free-range grass grazing for herds feature on pro-‘raw’ milk websites. Such discussions are also used as pro-‘raw’ milk consumption arguments. Perhaps the ‘raw’ milk advocates have a point. Many people in developed countries, as they seek healthier, more ‘natural’ food for themselves and their families, lean towards food sourced from more traditional style farms and processors. The rise in the organic food movement is a perfect example. Is this such a bad thing?

    Perhaps modern dairy-farming and milk processing practises have altered the taste and some properties of milk. Is it such a good idea to mix milk from multiple herds? Should dairy cattle be allowed to be free range? Is homogenisation a good idea and does it alter proteins in milk? Is it a good idea to fortify milk with vitamins? Perhaps ‘raw’ milk that is organic, free range and not homogenised is more ‘natural’ and resembles milk as it exits a cow’s udder than that which is pasteurised, homogenised, fortified and source from grain fed confined cows? Yes, I think it would. And this I can see is a big incentive for some people to consume ‘raw’ milk.

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    While researching the debate / controversy surrounding the consumption of ‘raw’ milk I have come across a number of websites and ‘raw’ milk advocacy organisations that list scientists as members of staff, contributors or active campaigners. I find this rather interesting.

    Does this lend these pro-‘raw’ milk groups air of legitimacy? Does it indicate to readers (members of the lay public, farmers and perhaps other scientists) that there is backing by those in the scientific community for some of the claims made about health benefits or the safety of ‘raw’ milk? Does it lend credibility to their side of the argument?

    Scientists and medical doctors may not necessarily be experts in food-borne illness, infectious disease and bacteriology, or dairy farming and milk processing. Are these individuals working outside of their area of ‘expertise’, training and knowledge? Are they qualified to comment on such topics as the risks involved in consuming ‘raw’ milk, bacterial pathogens in ‘raw’ milk, the safety of ‘raw’ milk, health claims and modern dairy farming and milk processing practises?

    The Raw Milk Institute, is an interesting case of an organisation that has a clear pro-‘raw’ milk message “uses and promotes science-based food safety principles to help create a secure foundation for the growing raw-milk movement.” The Institute has developed standards for raw milk production. Although there appears to be a lot of weight given to scientific qualification of its staff and the scientific research it conducts, there is still some pro-‘raw’ milk rhetoric throughout the content on the website, e.g. ” big believer in raw milk and used raw milk to fuel herself in the world’s hardest race.” Staff and members of the advisory council include a veterinary epidemiologist, alternative health practitioners, ‘raw’ milk farmers, artisan food producers, medical doctors, a biologist, ‘raw’ milk consumers and ‘raw’ milk advocates. Although the Institute “encourages, promotes and undertakes research, using approved scientific methods,” I am a little skeptical as the organisation is clearly biased towards ‘raw’ milk and clearly have an advocacy role to play. The fact that the Institute has developed standards by which dairy supplying consumers with ‘raw’ milk can work by is perhaps a good first step for regulation or ‘raw’ milk producers.

    Maybe some medical doctors and scientists are suitably qualified to common on the issues around ‘raw’ milk. Perhaps others are simply advocates that use their qualifications to lend credence to the pro-‘raw’ milk argument.

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    Following on from my post – Social Components to the ‘Raw’ Milk Debate, I am wondering if ‘consumer rights’ plays a large role in the active protest movements of the ‘raw’ milk advocates? And should the government take more notice of individual’s rights along with personal opinions and wishes.

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