Mutant Milk!? New Research Fuels the Flames on Hushed Up Concerns About Ill Health Effects of Homogenized Milk

Image 1: Wolverine could be the only face of the "Got Milk" campaign who does not have to care about potential negative health effects of homogenized milk.

In view of the fact that even the Wikipedia article on milk mentions the long-touted hypothesis that the release of the  membrane bound (bovine) xanthine oxidase during the homogenization process and it's potential to generate reactive oxygen specimen could pose a serious health risk, it's quite funny that none of the multitude of papers on the pro- or anti-atheriogenic effects of milk ever mentions mentions the issue of homogenization.

Now even if we discard the potential negative effects of BXO, the results of a recently published paper from the Center of Specialized Nutrition in the Netherlands would still suggest that milk does at least lose some of it's beneficial health effects in the course of the homogenization process (Oosting. 2012).

Large and fluffy or small? That does ring a bell, doesn't it? 

In their experiments the Dutch scientists fed mice infant formulas with either small or large phospholipid coated lipid droplets. Probably to the utmost satisfaction of Danone, the producer of the large lipid droplet formula (Nuturis) and sponsor of the study, the mice who received the regular formula with small lipid droplets were fatter and had compromised lipid and blood glucose levels (see figure 1), as well as pathologically increased leptin levels (not shown in figure 1).

Figure 1: It may remind you of comparing apples and oranges, but let's be honest, if it were not for the disruption of the large fat globules during the homogenization process, similarly large phospholipids as those Danone plans to unleash onto our children would be present in milk, anyway.

Irrespective of the funding and product pimping, the results of this study could have major implications that reach way beyond infant formulas and parenteral nutrition. After all, homogenized milk is common used in all sorts of milk based or milk-containing products. It's shelf stable and above all highly standardized and easily processable by the dairy and food industry, who are still spending truckloads of money to find means to further reduce the unwanted clumping that's so characteristic for the naturally occurring large fat molecules most of the end-consumer don't want to float on top of their heated milk either.

So, if the bovine xanthine oxidase that's released during the homogenization process does not, as Ho & Clifford and other researchers argued in the late 1970s (Ho. 1977), pose a risk for heart disease, what about the structural changes in the lipid fraction of milk? Do we know anything about these at all and could they be the underlying cause of the increase in allergies, diabetes risk that have never been convincingly attributed to milk consumption in general or whole milk consumption in particular? Did we focus to much on the quantity and type of fat in the milk and overlooked its structural organization?

Though shalt not fix something that ain't broken!

In a 2007 review of the literature on the potential impact homogenized milk could have on our health, Mikalski discusses exactly this question: What's the physiological consequence of the physical "rupture of fat globules" which occurs during the heating and homogenization process and "creates a new interface" on the membrane of the fat globules so that "other surface active components" (Mikalski. 2007) will more or less randomly adsorb to the remnants and form a new structurally different membrane.

Figure 2: After the homogenization process took place none of the original functional large fat globules is left, smaller ruptured globules have taken their place and are used by other molecules as a "Trojan horse" (left), distribution of milk fat globule sizes in different types of whole milk - open circles - raw whole milk, full circles - whole milk homogenized at 5MPa, open squares - whole milk homogenized at 10 MPa, full squares - whole milk homogenized at 50MPa (partly adapted from Mikalski. 2007)

Unfortunately, the #1 compound that will bind to the now the disrupted surface structures of the molecules in the homogenized monster milk are casein micelles (Zahar. 1996). Yep, exactly those molecules, of which some scientists, though most of them discard the hypothesis that homogenized milk is not at least as good for you as regular milk, still speculate that they could be responsible for many if not all of the aforementioned negative health effects of milk (Kohno. 1994; Laugesen. 2003; Tailford. 2003).

Homogenized, fat reduced zombie milk?

Figure 3: Distribution of milk lipids in globule core, membrane and skim phase (top, based on Michalski. 2007) and electron micrographs at 15× and 100× augmentations of (A) raw, (B) pasteurised, (C) homogenised–pasteurised, and ultra-high-pressure homogenised milk samples at (D) 100 MPa (Zamora. 2012)

That the process of homogenization will also affect the normal distribution of tri- and diacylglycerols, which are necessarily released from the core of the ruptured fat molecules (figure 3, top - blue) and modify the intricate phospholipid structure of the membrane (figure 3, top - red) should be as obvious as the fact that those tri- and diacylglycerols, phospholipids, cerebrosides and gangliosides are suddenly part of the skim fraction are easily lost during further processing (such as the removal of fat) and will have different physical attributes, physiological effects, digestive properties and absorption kinetics (cf. Berton. 2012).

The degree of homogenization increases according to the pressure that's used to force the the hot milk between valve needle and seat of the homogenization machine, so that  the aforementioned effects are particularly pronounced in the high-pressure homogenized milk (also "ultra-homogenized" milk). Accordingly even the last few "unwanted" (by the food industry) larger, intact fat globules that are left in the regular homogenized milk (figure 3, C) break apart.

What used to be a huge container-like fat molecule in the raw milk (figure 3, A), survived the pasteurization process relatively unharmed (figure 3, B) is now, after it has been pressed with 100MPa through the valve of the homogenization machine, nothing but a heap of very shelf-stable and non-clumping, highly convenient debris (figure 3, D) - awesome, right?

Bottom line: Aside from the disgusting taste of what we here in Germany call "H-Milch" ("h" as in "haltbar", which denotes the longer shelf-life) the structural changes and the potentially problematic downstream effects of the homogenization process, such as

Image 2: Assuming that the plastic canister the girl on the right holds in her hands contains homogenized milk, it may in fact be better for the girl on the left, if it was fat free :-o After all, when the homogenized whole milk is further processed into 0.2% = no fat milk ~95% of the previously created mutant fat molecules will be removed ;-)

• a rise in potentially artherosclerotic free bovine xanthine oxidase, which would otherwise be "locked" in the the intact milk fat globule membrane (MFGM),
• the formation of new lipid layers from casein and other milk components and milk fat globule membrane fragments with potentially allergenic, and inflammatory properties,
• a decrease in curd formation / stability, an increase proteolysis and lipolysis (=digestion of the proteins and fats) and the subsequent increase in nutrient absorption and speed in the gastrointestinal tract with its potentially detrimental downstream effects on blood lipids, and
• the increased absorption of casein molecules and the loss of the beneficial health affects such as the anti-viral, antimicrobial, anabolic and gut protective effects that have been ascribed to the natural MFGM structure of milk

should be reason enough not to make the most convenient, but the most natural choice - and that irrespective of whether the milk is for a toddler, a child, a teen or an adult... and by the way, the changes the fat molecules in the milk are undergoing and the subsequent "mutant" protein + fat fragment structures they are forming make the otherwise nonsensical advice to use "low" or better "no-fat dairy" actually appear quite sensible.

Apropos "high fat dairy", did I mention that the "bad high fat cheese" is not just almost always made from regular, non-homogenized milk (which is hard to get, these days, as even the cooled milk is routinely homogenized, so make sure to check the label), but that its consumption is also associated with a decreased risk of developing metabolic syndrome (Høstmark. 2011)? No... well, than that's even more food for thought ;-)

References

• Berton A,Rouvellaca S, Robertd B, Rousseaud F, Lopez C. Effect of the size and interface composition of milkfatglobules on their in vitro digestion by the human pancreatic lipase: Native versus homogenized milk fat globules. Food Hydrocolloids. 2012; 29:1, 123–134. 
• Ho C, Clifford A Bovine milk xanthine oxidase, blood lipids and coronary plaques in rabbits.J Nutr. 1977; 107, 758–766
• Høstmark AT, Tomten SE. The Oslo health study: cheese intake was negatively associated with the metabolic syndrome. J Am Coll Nutr. 2011 Jun;30(3):182-90.
• Kohno Y, Honma K, Saito K, Shimojo N, Tsunoo H, Kaminogawa S, Niimi H. Preferential recognition of primary protein structures of alpha-casein by IgG and IgE antibodies of patients with milk allergy. Ann Allergy. 1994 Nov;73(5):419-22.
• Laugesen M, Elliott R. Ischaemic heart disease, Type 1 diabetes, and cow milk A1 beta-casein. N Z Med J. 2003 Jan 24;116(1168):U295.
• Michalski MC. On the supposed influence of milk homogenization on the risk of CVD, diabetes and allergy. Br J Nutr. 2007 Apr;97(4):598-610.
• Oosting A, Kegler D, Wopereis HJ, Teller IC, van de Heijning BJ, Verkade HJ, van der Beek EM. Size and Phospholipid Coating of Lipid Droplets in the Diet of Young Mice Modify Body Fat Accumulation in Adulthood. Pediatr Res. 2012 Jul 31.
• Tailford KA, Berry CL, Thomas AC, Campbell JH. A casein variant in cow's milk is atherogenic. Atherosclerosis. 2003 Sep;170(1):13-9.
• Zahar M, Smith D- Adsorption of proteins at the lipid-serum interface in milk systems with various lipids. Int Dairy J. 1996: 6, 697–708.
• Zamora A, Ferragut V, Guamis B, Trujillo AJ. Corresponding author contact informationChanges in the surface protein of the fat globules during ultra-high pressure homogenisation and conventional treatments of milk. Food Hydrocolloids. 2012; 21:1, 135–143.

Childhood Asthma: Children Born to Mothers Who Consume Semi-Skimmed Milk 8% More Likely, Kids of Whole Milk Drinking Mothers 15% Less Likely to Develop Asthma

Image 1: Better make sure your "mother's milk" (the milk you drink while you or your significant other are pregnant) is full fat!

I don't know if you have listened to my "brother" Carl Lanore's Super Human Radio interview with Boyd Eaton, yesterday, but if you did, you will probably remember that the two also broached the issue of dairy consumption on a paleo diet. And while many of you may have been surprised to hear that Eaton does consume milk products on a regular basis, it is probably even more intriguing that the show came full-circle only a couple of minutes later, when Carl who had just addressed the issue of iron-overload and how that relates to the relative abundance of meat in an ancestral diet, read my facebook message about the beneficial effects of milk proteins, Zunquin et al. observed in a 2006 trial rodent trial intended to simulate the potential side effects of high dose iron supplementation to replete iron stores in iron-depleted athletes (Zunquin. 2006).

Milk allergy or allergy due to the lack of full-fat milk - is that the question?

Yet while the Zunquin study is by no means the only scientific evidence that nature's original meal replacement, irrespective of whether or not it may be "intended for human consumption" can exert potent health effects (cf. Barfray. 2003), the pros and cons of a high(er) intake of dairy is still a matter of constant debate. Other than within the paleosphere, the public and scientific debate does yet usually revolve around the notion of low- vs. high fat dairy, with the common recommendation to "choose low fat dairy in order to avoid the unhealthy saturated fats that come with the full-fat variety".

Figure 1: Associations between mothers' consumption of milk and dairy during pregnancy and incidence of early childhood asthma (18 months) in children from the Danish national Birth Cohort; data expressed as differences to no-consumption (data based on Masolva. 2012)

Aside from the downside of non-existent yet potentially healthy levels of certain fatty acids, such as conjugated linolic acid (yeah, the one that can kill empty fat cells, cf. "Nasty Insights into the Yo-Yo-Effect: Lower Body Fat Sticks and From Fit2Fat There's no Easy Way Back!"), the reduced absorption and presence of fat-soluble nutrients and the necessity to add sugar or artificial flavors, as well as chemicals to modify the taste and mouth-feel of those watery low-fat dairy products, a recent study from Department of Nutrition at the Harvard School of Public Health in Boston does now provide compelling evidence that either one or all of the former aspects, or a hitherto not elucidated difference between skim and full-fat dairy products increases children who are born to mothers who consume >5 portions of semi-skimmed milk per week during their pregnancy have an 8% increased risk of developing childhood asthma and a 40% increase in risk of developing allergic rhinitis later in life (Maslova. 2012).

Table 1: If you are interested in other sources of CLA (and omega-3), in general, and the difference between grass- and grainfed beef, in particular, check out this table from a Daley et al. (Daily. 2012)

What's even more intriguing, though, is that the consumption of equal amounts of full fat milk was associated with a statistically significant 25%(!) reduction in asthma-risk (and recurrent wheeze symptoms) in the ~60,000 children / mother pairs from the dataset of the Danish National Birth Cohort the US scientists analyzed. Similarly, there was a

"dose–response was present for semiskimmed milk intake, while any intake of full-fat yoghurt appeared to be protective of child asthma" (Maslova. 2012)

that did, just as the aforementioned results, remain significant, even when the data was adjusted for the intake of other allegedly beneficial foods (fruit and vegetables) and nutrients (vitamin E, vitamin D, Se, Zn from diet and supplements).

So are those the CLAs and other ruminant trans-fats?

While Malsova et al. fail to give a clearcut answer on what the underlying reasons for these observations are, their detailed analysis of the data does yield some evidence that CLAs and other ruminant trans-fatty acids cannot explain the differences, as they showed similar correlations with both full-fat and semi-skimmed milk intake and were "not associated with either the early or later childhood outcomes" (Maslova. 2012).

Image 2: Not, not all full-fat milk drinkers worked on a farm ;-)

An analysis of other potentially confounding lifestyle factors yielded similarly inconclusive results so that this leaves us without a causal explanation for either the protective effect of whole milk and full-fat yogurt intake on early childhood asthma or the increased risk to develop wheeze at 18 months in children born to high consumers of semi-skimmed milk. In the absence of any information of what happened in the course of the following 7-years it appears futile come up with any hypothesis that would explain the direct associations of maternal low-fat yoghurt consumption with child asthma and allergic rhinitis and the "suggestive" relationship of the latter with total milk intake, anyways. And as the scientists say:

The diversity and complexity of our results make it difficult to interpret and propose a single agent mechanism, yet the consistent associations with low-fat yoghurt for later childhood outcomes suggest that compounds specific to this food, such as artificial sweeteners, may play a role.

Interestingly, they specifically refer to the use of aspartame as the "primary" artificial sweetener in the Danish food supply since the 1980s, but cite a - at least in my humble opinion - highly biased source (Gideon. 2010) on that issue without even providing a single scientific study that would implicate aspartame as a factor involved in the etiology of asthma (+my brief research shows, there is none).

Image 3: Too much statistical shenanigan involved in the ER data for my liking.

A note on additional data evaluated in the study: The scientists make use of the actual hospital admissions due to asthmatic reactions as another source for their study data. Unfortunately, those only contribute to the already confusing results, because they suggest that despite the fact that the incidence of early childhood asthma is lower (other data), the chance to end up in hospital, as assessed by data from the Danish National Patient Registry appears to be higher in children born to mothers with a high full fat milk intake (+30%), and minimally reduced for children whose mothers consumed the same amount of skimmed dairy - it is however questionable how reliable this 3rd hand data which had to be linked back to the central person registry first and ran through multiple processing steps actually is (same for data from the Register of Medicinal Product Statistics).

As far as the underlying mechanisms are concerned this leaves us with but one relatively certain conclusion: The scientists' initial hypothesis that ruminant trans-fatty acids could play a causal role in the development of allergic disease development cannot be upheld in view of the inverse associations Maslova et al. found between the CLA content and the risk to develop asthma and/or allergic rhinitis across products with different fat content.

Suggested reading:

• Ask Dr. Andro: Are Colostrum and Milk Products in General Healthy Muscle Builders, a Waste of Money or Toxic Waste? 
• Whey and Casein Work Hand in Hand for Protein Anabolism, but Scientists Overlook Fat, When They Reassemble Milk  
• Coke vs. Diet Coke vs. Milk - The "Unhealthy Beverage Shoot-Out": Milk Reduces, Coke Increases Visceral Fat. Dreaded Diet Coke on Par With Plain Water  
• The Fat Truth Behind the Dairy Weight Loss Miracle: MUFA and PUFA Impair, Saturated Fat and Plenty of Micronutrients Drive Full-Fat Dairy-Powered Fat Loss. 
• Want B12, But Hate Meat? Drink Milk! SNAC-Fortified Cyanocobalamin 136% More Bioavailable Than Standard B12 - Still Less Effective Than B12 From Cow's Milk

References:

1. Bartfay WJ, Davis MT, Medves JM, Lugowski S. Milk whey protein decreases oxygen free radical production in a murine model of chronic iron-overload cardiomyopathy. Can J Cardiol. 2003 Sep;19(10):1163-8. 
2. Daley CA, Abbott A, Doyle PS, Nader GA, Larson S. A review of fatty acid profiles and antioxidant content in grass-fed and grain-fed beef. Nutr J. 2010 Mar 10;9:10.
3. Gideon B (2010) Aspartam: Nu også i ikke ‘Light’ produkter. < http://infowars.dk/content/aspartam-nu-ogs%C3% A5-i-ikke-light-produkter > last accessed on July 10, 2012
4. Maslova E, Halldorsson TI, Strøm M, Olsen SF. Low-fat yoghurt intake in pregnancy associated with increased child asthma and allergic rhinitis risk: a prospective cohort study. Journal of Nutritional Science (2012), vol. 1, e5.
5. Zunquin G, Rouleau V, Bouhallab S, Bureau F, Theunynck D, Rousselot P, Arhan P, Bougle D. Iron and exercise induced alterations in antioxidant status. Protection by dietary milk proteins. Free Radic Res. 2006 May;40(5):535-42.