Pasteurization Does Harm Real Milk

Health-PastDoesHarm-600x626By Robert Irons, PhD

Proponents of raw milk know that government websites and reports on raw milk are filled with bias and even outright errors. I recently wrote to the Centers for Disease Control to point out a serious error on their website. My comments apply to milk in general, regardless of species, because pasteurization degrades the nutritional value of all species’ milk in the same manner. Just as a calf cannot thrive on pasteurized cow’s milk, so a human baby fails to thrive on pasteurized mother’s milk.

Nutritional Value of Raw Milk

In paragraph two of a section entitled “Pasteurization Is Key to Making Dairy Products Safe” is the statement “Pasteurization does not harm the nutritional value of milk and cheese” (

This statement is erroneous, misleading, and factually incorrect. Many nutrients and immune-enhancing components are destroyed by exposure to high heat and the temperatures used during pasteurization. Vitamin A is degraded, proteins and enzymes are denatured, and immunoglobulins are destroyed.

Vitamin A

Regarding vitamin A, an important fat-soluble nutrient, a paper on this subject published in January, 2000 contains the following statement in the abstract. “Vitamin A is very sensitive to chemical degradation caused by oxygen, light, heat, and other stress factors. If light and oxygen are excluded, the dominant degradation reaction for vitamin A derivatives is heat-induced formation of kitols, that is, dimers or higher oligomers” (Runge FE and Heger R. Use of microcalorimetry in monitoring stability studies. J Agric Food Chem. 2000 Jan;48(1):47-55).


A related error on the CDC site concerns salmonella. The agency’s official advice is “Cook poultry, ground beef, and eggs thoroughly before eating. Do not eat or drink foods containing raw eggs, or raw unpasteurized milk” ( g.htm).

However, later on this page we read: “Mother’s milk is the safest food for young infants. Breastfeeding prevents salmonellosis and many other health problems.”

In one instance the CDC warns not to drink unpasteurized milk, and seven points later—within the same section—states that an unpasteurized milk (i.e., mother’s milk) is the safest food for young infants and that breastfeeding prevents salmonellosis and many other health problems. This is highly misleading to the average citizen.

Growth in Premature Babies

There is no question that pasteurization compromises the nutritional value of breast milk. For example, research carried out in 1986 came to the following conclusion (emphasis mine): “As part of a randomised controlled study to assess the effect of pasteurization of breast milk on the growth of very-low-birth-weight infants, the longitudinal changes in serum calcium, phosphorus, alkaline phosphatase, 25-hydroxyvitamin D, and bone-gla-protein concentrations were investigated. Infants fed untreated own mother’s milk grew more rapidly than those fed pasteurized pooled preterm milk and had higher serum alkaline phosphatase and lower phosphorus values. Serum calcium and 25-hydroxyvitamin D (25-OHD) concentrations were similar in the two groups. Despite the provision of 750 IU vitamin D daily from the 2nd week of life, serum 25-OHD values remained low in a number of infants in both groups, suggesting that either malabsorption of vitamin D or hepatic immaturity might be responsible for the persistently low values. Bone gla protein rose significantly after birth and was correlated with alkaline phosphatase values, but not with 25-OHD or phosphorus values. The study supports previous work that indicates that the low phosphorus content of breast milk is probably responsible for biochemical evidence of inadequate bone mineralization and that despite vitamin D supplementation, 25-OHD values do not rise adequately. Thirty-six infants were reexamined between 4 and 11 months after birth. The 25-OHD values had risen significantly in all infants except one who had vitamin D deficiency rickets” (Pettifor JM et al. Mineral homeostasis in very low birth weight infants fed either own mother’s milk or pooled pasteurized preterm milk. J Pediatr Gastroenterol Nutr. 1986 Mar-Apr;5(2):248-53).

Another study carried out in the same year came to the same conclusion (emphasis mine): “It has been shown that milk derived from mothers with term infants is not optimal for premature babies. There is also concern about the effect of heat sterilizing breast milk. At Baragwanath Hospital, the majority of mothers remain with and care for their premature babies. Over many years, pooled pasteurized breast milk has been fed to these babies before direct breast feeding is instituted. A study was done to compare feeding pooled pasteurized breast milk and untreated own mother’s milk to very low birth weight babies. There was a significantly more rapid weight gain both in terms of regaining birth weight and, from this point, to reaching a weight of 1,800 g when using untreated own mother’s milk. This occurred in spite of the fact that there was little difference, especially in terms of energy content, between the two types of breast milk. This was due to the fact that the pooled pasteurized milk was also largely obtained from mothers of premature babies. It is suggested from our data that  slower weight gain in the group receiving the pooled pasteurized milk could be due to the pasteurization, which probably destroys heat-labile milk lipase” (Stein H et al. Pooled pasteurized breast milk and untreated own mother’s milk in the feeding of very low birth weight babies: a randomized controlled trial. J Pediatr Gastroenterol Nutr. 1986 Mar-Apr;5(2):242-7). Note that the researchers atrribute the lower weight gain from pasteurized milk to the destruction of lipase.

Destruction of Enzymes

From a study published in 1977 we learn: “Human milk was subjected to heat treatments of graded severity and examined for its content of immunoglobulins, lactoferrin, lysozyme, vitamin B12 -and folate-binder proteins, and lactoperoxidase. Holder pasteurization (62.5 degrees C 30 minutes) reduced the IgA titer by 20 percent, and destroyed the small content of IgM and most of the lactoferrin. Lysozyme was stable to this treatment, but with an increase in temperature there was progressive destruction, to near 100 percent at 100 degrees C. The same was broadly true of the capacity of milk to bind folic acid and protect it against bacterial uptake; with vitamin B12 the binder was more labile at 75 degrees C than at 100 degrees C. The milk contained no detectable lactoperoxidase” (Ford JE et al. Influence of the heat treatment of human milk on some of its protective constituents. J Pediatr. 1977 Jan;90(1):29-35).

Obligation to Remove

These studies apply to the milk of all species, not just human milk. Americans look to the CDC to provide factually correct information that is not misleading. The above references prove that pasteurization does harm the nutritional value of milk. Therefore, the CDC is obliged to remove the following erroneous statement from its website, recommendations and all other CDC materials: “Pasteurization does not harm the nutritional value of milk and cheese.”

The available scientific evidence shows that pasteurization does harm the nutritional value of milk and cheese.

This article appeared in the Spring 2008 edition of Wise Traditions, the quarterly journal of the Weston A. Price Foundation.

Dr. Robert Irons earned his PhD in Nutritional Immunology from the University of Missouri-Columbia. His graduate work examined the effects of omega-3 polyunsaturated fatty acids from fish oil on primary and secondary immune responses to infectious disease. He received postdoc training at the National Institutes of Health/National Cancer Institute with a dual role in the extramural Nutritional Sciences Research Group; and the intramural Laboratory of Cancer Prevention, where he conducted research on the cancer protective effects of selenium against colon cancer in mice. He has published in peer-reviewed journals such as the Journal of Nutrition, Journal of Infectious Disease, and Biochemical Journal. He has served as research consultant to the Adele Davis Foundation and the Price-Pottenger Nutrition Foundation. Dr. Irons received first prize for his poster presentation at Wise Traditions 2007. Dr. Irons is Vice-President of Research and Development at V.E. Irons, Inc., a dietary supplement manufacturer established in 1946. He can be reached at robert (at) or (816) 221-3719 extension 704.

19 thoughts on “Pasteurization Does Harm Real Milk

  1. Raw milk doesn’t effect me negatively, and it tastes better than Pasteurized milk. I’m severely lactose intolerant with regular milk, and even with lactose-free milk it’s a little bit better, but both lactose-free milk or even goat milk still effect me negatively. I’ve tried soy milk and rice milk, and both are fine, but soy is just a bit thick, rice milk seems too watery, and I don’t like the taste of almond milk. I’ve never had issues with Raw milk when I’ve had it.

    • Those substitutes you mention don’t have saturated fat in them nor taurine or iodine they are no good . The reason it’s called milk is because you milk the animals teet’s .

  2. I would recommend you look up your state’s standards for what is considered “commercial grade milk.” I would be willing to bet that if this person isn’t being monitored by the state or processors that his milk is sub standard. Have you asked your local dairyman if he/she tests his milk for what the bacterial and coliform count is? Did he/she explain to you what the process is that he/she uses? What temp, how long?

  3. Well first of all Dr. Irons, your first argument is pretty flawed. You cannot compare the effects of pasteurization on growing infants and calves to its effects on grown adults who no longer need to rely on the chemical properties of milk for growth and development. I enjoy dairy myself but it isn’t such a large percentage of my dietary protein or fat intake (or anyone’s for that matter) that I need to concern myself with not getting enough milk protein, which we actually don’t need as adults if people would just eat well. Secondly, both young animals and young people do thrive on pasteurized milk, colostrum, and even milk replacer products. I think we as humans, and especially humans living in a first world country, are experiencing an interesting time in history. We have become so technologically advanced that we have forgotten about a past when men, women, and children suffered regularly from food borne illness, a large portion of them from the consumption of dairy products. Today we have the luxury of rejecting processes such as pasteurization and vaccinating (I’m not comparing the two) because we seldom see, if at all, the effects of a time when these processes weren’t available to us. The fact of the matter is this: people do not consume so much dairy that they need to concern themselves with a few denatured whey proteins. Furthermore, milk does contain harmful pathogens that can make a person or child very very ill. Weigh the odds, drink something that is nutritious and could hurt you (raw milk) or drink something that is also very nutritious and is very safe (conventional pasteurized milk). It’s a fad that even scientists are buying into. I would ask that you spend a little time on some dairies, in the lab, and over the microscope. I would also add to the readers, don’t take advice at face value, look up the science yourselves! It’s out there for free!

    • I don’t see that anywhere he is comparing the effects of pasteurization on growing infants and calves to its effects on grown adults. This article is primarily focused on the nutritional value of raw vs. pasteurized specifically when it comes to infants. Many infants do not thrive on pasteurized milk or milk replacer products, which is why our raw milk formula is so popular with desperate mothers who are unable to make enough breastmilk and whose babies don’t thrive on commercial formula (literally, many described with the term “failure to thrive” have thrived once put on our raw milk formula). This site is full of articles about safe production of raw milk. Like any other food, if not produced and handled safely it could cause food-borne illness. Both raw milk and pasteurized milk are very safe relative to other foods as we’ve pointed out many times on this site (raw oysters, deli meat, salad greens, etc. are all potentially dangerous). I agree that readers should not take advice at face value. Look up the references in the scientific literature. We annotate our articles to help you do that.

  4. Hi Sally,
    Your comments about milk production from Organic Pastures illustrates my previous points. If this had been for the total milk for retail to the USA population, I would have been impressed but you only cite one example. I spoke to a lady there but she could not supply more specifics. So from their Web site, it would seem they fall into the category I described as Boutique. Which returns to my original comments, that for most milk from general production for retail to the general public, pasteurisation provides a level of safety from disease that Raw Milk does not.
    In the 50’s Scotland was on Steam Sterilisation at the farm level, the bacterial standard for Raw milk, water cooled to below 60°F in cans was by Standard Plate Count and Coliform delivered to the processing plants. I cannot remember the details but they were discussed with envy in Victoria in the 70’s when they were contemplating changing from Methylene Blue to Thermoduric Count or <30,000 per ml.
    If you want a historic run through, I will email you directly.

    • Sally Fallon Morell replies: The goal is to have tens of thousands of boutique raw milk farmers in the US. Every family will have connections to a farm. This is the wave of the future. There will also be plenty of medium sized dairies, such as Organic Pastures at 400 cows. After all, America was fed with milk from dairies these sizes for decades.

  5. I was commenting on my experience in the UK prior to 1970 and Victoria and Queensland in Australia prior to 1982 where sale of Raw Milk as I described is not currently legal. They therefore would be not immediately applicable to the situations you describe in the USA. My college training was from 1953 to 1956 where the debates about Raw Milk v Pasteurisation were VERY current and still continued into the latter parts of the 20th Century in some areas. They were also applicable to Milk for sale to the general population where there was even misunderstandings about the effects of Homogenisation.

  6. Hi Sally,

    I was taught that Denaturation of Protein will result in it no longer being in the Colloidal Sol.
    Water freezes at 0.00°C and as milk has salts in solution the temperature at which it freezes is lower or Depressed below this temperature. One of the standards applied to milk standards is/or was years ago, is the Freezing Point Test where milk is frozen and the temperature at which it freezes is an indication of either added water or irregular milk, such as what happens with cows on very poor pasture or other inadequate nutrition. Before the use of the Thermistor Cryoscope, this was measured with a very sensitive Mercury-in-Glass thermometer (Hortvet) and the Freezing Point was expressed in Degrees H. This was somewhat clumsy so the result was called the Freezing Point Depression and the standard FP Depression was 0.54° The Cryoscope was more sensitive and precise and it was found that ‘Normal’ milk produced under monitored conditions was failing so the standard was revised. A smaller depression (nearer to 0.0°C) is take to be indicative of ‘abnormal milk’.

    There is a very informative pdf on the subject at which deals with the subject in much more detail.

  7. Addition of ‘Chalk’ would be fairly pointless in Retail Milk as it would be virtually insoluble and precipitate. Unpasteurised milk from your own healthy cows would be OK but Pasteurisation was introduced to kill Tuberculosis in the milk for general consumption. This also inactivates the toxin from Brucellosis which can cause Undulant Fever. I have visited many dairy farms as part of my work and from what I have seen convinces me that Pasteurisation is a wonderful process.
    I also was involved in commercial Cheddar Cheese and notwithstanding the historic claim that their cheddar cheese would not be beaten for flavour by cheese from heat treated milk, the average consumer would not taste a definitive difference. Certainly what I experience in the local supermarket, the ‘Tasty’ label covers a multitude of very indifferent tastes and textures.
    I nowadays have greater concerns about the amounts of Antibiotics in Market Milk which has helped to allow the emergence of ‘Superbugs’ and antibiotic resistant strains of many previously treatable diseases. From my cheese-making days, bulk milk tankers were tested daily and any positive were pumped to large holding tanks to reduce the concentration and the Enzyme Penase added I the hope that the culprit was Penicillin otherwise the cheese starter would be adversely affected. When I was milking, milk from treated cows was fed to bucket-fed calves.

    • As part of your work are you visiting dairy farms where the farmers are dairying in order to sell to the commercial market, in other words, are they producing milk meant to be pasteurized? Or are they producing milk intended to be consumed raw? Milk intended for pasteurization has different standards than that for raw milk consumption.

      • I grew up and entered the Dairy Industry in the UK but emigrated in 1970 so I have not kept up with developments there. Currently I live in Queensland Australia where sale of Raw Unpasteurised milk as FOOD for human consumption is illegal, so all the farms I visited were selling milk intended for sale as Food and therefore would be pasteurised. Raw Milk may be sold for ‘Cosmetic’ application and labelled accordingly but not used for Food. Goats’ Milk is not subject to the same legislation.
        I am unaware of the standards for milk in the USA. However, although Raw Milk may have different standards applied to it would seem to have the problems associated with human nature, integrity, commercial pressures, sterilisation of equipment, clean practice, healthy cows and absence of accidents. Application of regulation to cover these scenarios would be impossible to police and enforce in the real world. Raw milk from Boutique Suppliers might be a feasible situation but I fancy cost pressures , distribution and marketing would place it beyond the reach of the general public.
        In the real world, cows get mastitis, tuberculosis and other diseases from birds and other wildlife, walk through mud and cow dung, get foot rot, get flies over their udders, get treated by vets, may not get their udders thoroughly cleaned before milking, the fore milk is not rejected and a multitude of other scenarios that pasteurisation (HTST 72°C for 20seconds) screens out from the general public. The Bovine Tuberculin Attestation Scheme considerably reduced the incidence of Tuberculosis and the Brucellosis Eradication Scheme reduced incidences of Undulant Fever.
        On example I can cite is when I was in Victoria on the Butter and Milk Powder processing plant where I worked, it was common practice to get some raw milk from one of the Farm Collection tanker for consumption in the coffee rooms. One employee became ill from Undulant fever and the practice was forbidden and Pasteurised milk was supplied by the company. It was considered that the cost justified the end result.
        I could go on…. but suffice to say that whatever degradation of the nutritional value of cows milk by effective pasteurisation for sale to the general public is compensated by the reduction of disease in the population.

        • We have many articles on this site, and the Farm-to-Consumer Legal Defense Fund ( also has articles, videos, etc. on safe production of raw milk. There are also decades of history of safe consumption of raw milk in the United States. That is not to say no one ever gets sick, but that it is rare. In fact, CDC data shows that far more food borne illness comes from raw produce than milk (raw or pasteurized). Milk is a low risk food. Careful animal husbandry and raw milk handling processes reduce the risk further.

          Your anecdote about the raw milk for the coffee rooms at the processing plant is interesting, but we have been saying for years that there is a difference between raw milk intended for pasteurization and raw milk intended to be consumed raw. The Raw Milk Institute (RAWMI) in the US is forming standards and certifying farms that meet these standards for safe production.

        • Finally, someone commenting that has practical, real world experience and isn’t just blowing smoke out of there ass. The general public is so removed from their food sources. I imagine I would be hard pressed to find someone who spent a day working on a real dairy reject pasteurization afterward.

          • Except for the thousands of farmers listed on this site who work all day on their “real” dairies (maybe you think they’re too small to be “real”?) to offer raw milk and drink it themselves.

  8. If the proteins were totally denatured and come out from Colloidal Sol then I would thought they would be able to removed by filtration? Would this not also the affect the Freezing Point Depression such that the standards would be variable for Raw and Processed. I don’t remember that this was the case.

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