Robert Cohen, Executive Director of the Dairy Education Board, wrote in his article "Homogenized Milk: Rocket Fuel for Cancer," accessed Nov. 28, 2007 on the Health 101 website:
"Homogenization is the worst thing that dairymen did to milk. Simple proteins rarely survive digestion in a balanced world.
Milk is a hormonal delivery system. With homogenization, milk becomes a very powerful and efficient way of bypassing normal digestive processes and delivering steroid and protein hormones to the human body (both your hormones and the cow's natural hormones and the ones they were injected with to produce more milk).
Through homogenization, fat molecules in milk become smaller and become 'capsules' for substances that bypass digestion. Proteins that would normally be digested in the stomach or gut are not broken down, and are absorbed into the bloodstream...
Homogenized milk, with its added hormones, is rocket fuel for cancer."
Thomas E. Levy, MD, JD, Associate Professor at Capital University of Integrative Medicine, wrote in his 2001 book, Optimal Nutrition for Optimal Health: The Real Truth About Eating Right for Weight Loss, Detoxification, Low Cholesterol, Better Digestion, and Overall Well-Being:
"So what's the harm in homogenization? Cow's milk contains an enzyme of large molecular size called xanthine oxidase (XO). XO is normally attached to the fat globules in milk. However, when these fat globules are in their natural large-sized state prior to homogenization, they are not easily absorbed by the gut wall. After homogenization, the milk fat is easily absorbed, and the attached XO gains much greater access to the bloodstream.
Some researchers [such as Dr. Kurt Oster and Dr. Donald Ross] have asserted that XO, after getting into the bloodstream, directly promotes hardening of the arteries by replacing a substance called plasmalogen that is normally found there. The research supporting this connection between XO and hardening of the arteries is not clear-cut, but whether or not there is a definite cause-and-effect relationship between the two should not be a critical factor in deciding whether you should drink milk. This possible XO link to heart disease is but one more potential connection of milk to disease and premature death."
Margaret Moss, MA, Director of the Nutrition and Allergy Clinic in Greater Manchester, UK, wrote in a Jan. 2, 2008 e-mail to ProCon.org that:
"Homogenisation of milk may make coronary heart disease more common and more serious. Fat globules in cows' milk are surrounded by membranes. Some people make antibodies to these membranes. The antibodies cause human platelets to clump together, at least in the laboratory. It is thought that this occurs in real life, encouraging clotting in patients who have the antibodies. The antibodies also bind to natural killer cells, one of whose functions is to reduce inflammation. When the antibodies are bound to them, the action of these cells is suppressed, increasing inflammation. We know that inflammation plays a part in coronary heart disease. Homogenisation breaks up milk fat globules, increasing the surface area of the membrane, which is likely to increase the antibody response. Xanthine oxidase has been suggested as the part of the milk fat globule membrane that causes the formation of antibodies, but other components may be involved."
Laura Paajanen, Division of Nutrition at the University of Helsinki, and Tuula Tuure, Researcher at Vailo Ltd., et al., wrote in their 2003 article, "No Difference in Symptoms During Challenges with Homogenized and Unhomogenized Cow's Milk in Subjects with Subjective Hypersensitivity to Homogenized Milk," published in the Journal of Dairy Research:
"In the present study…[n]o differences in the symptoms during the challenges with the homogenized and the unhomogenized milk were discerned. Our findings are in agreement with the data of previous double-blind studies: in double-blind, placebo-controlled trials no difference between the homogenized and the unhomogenized milk has been shown in the symptoms of cow's milk allergic children (Høst & Samuelsson, 1988) or of lactose intolerant adults (Vesa & Korpela, 1994) or in the symptoms and complement receptor expression of milk hypersensitive, lactose intolerant or control subjects (Pelto et al. 2000)."
Andrew J. Clifford, PhD, Department of Nutrition at the University of California Davis, Charles Y. Ho, PhD, Division of Biological Sciences at Emporia State University, and Helene Swenerton, PhD, Department of Nutrition at the University of California at Davis, wrote in their Aug. 1983 article, "Homogenized Bovine Milk Xanthine Oxidase: A Critique of the Hypothesis Relating to Plasmalogen Depletion and Cardiovascular Disease," in The American Journal of Clinical Nutrition:
"Homogenized milk was first proposed as a culprit in the development of heart disease in 1971 [by Dr. Kurt Oster]. Homogenization of milk was described as a 'procedure which foists unnaturally small particles on our digestive tract.' Xanthine oxidase, absorbed from micro- sized lipid droplets of homogenized milk, was reported to cause tissue damage and initiate the atherosclerotic process which culminates in ischemic heart disease.
The plasmalogen depletion/xanthine oxidase hypothesis has been reviewed and discussed in relation to recently published experimental data...
In summary, experimental evidence has failed to substantiate, and in many cases has refuted, the hypothesis that homogenized bovine milk xanthine oxidase intake or plasmalogen depletion are causal factors in the development of atherosclerosis."
Marie-Caroline Michalski, PhD, Researcher at the National Institute of Agriculture at the University of Lyon, et al., wrote in the 2006 article, "Does Homogenization Affect the Human Health Properties of Cow's Milk?," published in Trends in Food Science and Technology:
"Homogenization seems to improve milk digestibility for subjects suffering intestinal disease…
[T]he effects of milk homogenization and heating regarding the bioactivity of casein peptides and the cardiovascular impact of milk consumption should be elucidated. Studies found to date do not show any impact of homogenization on milk allergy or intolerance in humans."
[Editor's Note: ProCon.org received an e-mail from Dr. Michalski on Mar. 18, 2008 in which she reiterates that to date there is a "lack of clearcut research results" about the effects of homogenization.]