01.08.2011 Natural Health

Unwholesome Truths

Health researcher Peter Dingle PhD finds disturbing links between cow's milk and serious illness including heart disease, cancer, MS and type 1 diabetes

Evidence has been steadily mounting during the past few decades of the potential negative effects of dairy on human health, from colic and gut disorders to cancer. Milk is associated with many digestive disorders, poor gut health, food intolerances and allergies. Many children develop food intolerances to milk, which, at the very least, cause overproduction of mucus and lots of phlegm and runny noses. Worse, these intolerances can cause severe allergic symptoms. This is often related to the negative impact dairy products have on the gut. Associated with this, I have seen colic clear up in many infants once they are taken off dairy.

Lactose intolerance is a "condition" in which the body cannot digest the sugar efficiently (or at all), leading to poor gut health and excess mucus, acid and gas production and varying degrees of abdominal discomfort (1). People with lactose intolerance also experience reduced absorption in the gastrointestinal system (2). Approximately 75% of the world's population (particularly in Eastern countries such as China and India, throughout Africa and in minority populations such as Australian Aboriginals and Native Americans) has a level of lactose intolerance (1), and it is now generally accepted that this "condition" is actually the norm for the human species. It is more prevalent in Asians (about 85%) and African Americans (about 50%) than Caucasians (about 10%). It should be highlighted that the inability to digest lactose is exacerbated by pasteurisation destroying all the enzymes naturally found in milk that would normally help with digestion of the milk.

A food allergy is an abnormal immunological response due to a sensitisation to a food or food component. It represents an important health problem, especially in industrialised countries where it has been estimated to affect about 1% to 2% of the adult population and up to 8% of children below the age of three (3). As far as statistics go, cow's milk allergy can be considered one of the most common food allergies, especially in early childhood with an incidence of 2% to 3% in the first years of life (4).

If an allergic reaction develops, it is not always due to the dietary habits of the infant. A baby can be exposed to the proteins that cause an allergic response. Breast milk from mothers who have consumed products containing cow's milk might be another threat for the development of cow's milk allergy due to the absorption of cow proteins, their passage through the gut mucosa and their release in human milk (4). Antibody reactivity to bovine casein, as well as to casein and lactoglobulin, is detectable only in bottle-fed infants and not in infants who are exclusively breast-fed (5).

Hormones and growth factors
Many of the bioactive components of milk contain hormones and growth factors. Milk contains more than 50 hormones and growth factors (6). The consumption of cow's milk can result in significant hormonal changes and disrupt the balance of insulin, growth hormones and insulin-like growth factors (IGF) (7). Insulin Growth Factor One (IGF-1) is intended to assist suckling calves to grow and produce new tissue through the prolific reproduction of cells (8). However, when this hormone is introduced to the adult human body, which is no longer growing, cells may be encouraged to reproduce at the wrong time or place, providing the basis for cancerous growth (9). Cow's milk and human milk share the same amino acid sequence of IGF and therefore the cow form is capable of binding to human IGF (10). Numerous studies have shown a link between these hormone levels and levels of IGF in prepubertal boys and girls (11) and, as a result, such levels have been positively correlated with increased height (12,13). The levels of IGF-1 in dairy milk may have increased significantly with the increase in milk production per cow since the beginning of the Agricultural Revolution. This problem is compounded in the US where they can add IGFs to milking cows to increase milk production. There is some scientific debate centreing on whether homogenisation allows the hormone to be digested and consequently reach the bloodstream (14).

Insulin Growth Factor One (IGF-1) has been linked with numerous types of cancer, including prostate and breast cancer (15,16) and cow's milk consumption has been strongly associated with an increase in hormone-dependent cancers (17). A large study, a meta-analysis, found that high intake of dairy products and calcium was associated with an increased risk of prostate cancer. Researchers found men with the highest intake of dairy products were more likely to develop prostate cancer than men with the lowest intake (18). Dose-response analyses suggested that dairy product and calcium intakes were each positively associated with the risk of prostate cancer. That is, the more dairy consumed, the higher the rates of prostate cancer (19,20,21). One study found a 5.1 times higher risk of advanced stage prostate cancer (22) while another found that milk consumption was most strongly associated with mortality rates of prostate cancer (19). A strong link has also been found between dairy consumption and testicular cancer (24,25,26).

A study of 3,300 cancer patients and 1,300 control subjects (27) comparing milk and dairy intake between the two groups found a significant association between the exclusive consumption of whole milk and increased risk of certain cancers (including oral, stomach, rectum, lung and breast). Most of the subjects in the control group were drinkers of reduced fat milk or non-fat milk, linking the reduction in saturated fat to a reduction in oral and cervical cancers. A number of other studies have linked dairy consumption with breast cancer (28-32) as well as ovarian cancer (33).

Diabetes mellitus (type 1)
Cow's milk-based infant formulas and cow's milk consumption in childhood have been found to promote the development of type 1 diabetes mellitus and other immune-mediated or neurological diseases. The introduction of cow's milk-based infant formula within the first three months of life is associated with increased risk of type 1 diabetes mellitus (34-38) and there are more than 100 studies linking early exposure to dairy milk to the onset of diabetes mellitus (type 1) in children who are genetically prone to the disease (37-43). The evidence for this association is overwhelming. Furthermore, in animal models of type 1 diabetes mellitus, cow's milk proteins have been proven to lead to the development of diabetes.

In a study on newly diagnosed type 1 diabetes, researchers found the children in the study had antibodies that were primed to attack cow's milk proteins. These antibodies had apparently risen in response to cow proteins in their infant formula, but the antibodies were also capable of attacking the body's insulin-producing cells. The antibodies that arose to destroy the cow's milk protein ended up attacking the children's insulin-producing cells. The infant's immune system recognises these bovine proteins as foreign and forms antibodies to attack them. Unfortunately, these antibodies attack not only the cow proteins but also the insulin-producing cells in the pancreas.

There is so much concern about this that a worldwide study has begun in which children are being kept off all cow's milk to see whether diabetes can be prevented (7).

Multiple sclerosis
Evidence dating back to 1976 44 shows that cow's milk consumption is linked with the development of multiple sclerosis (MS) (45-48). One study of dairy consumption in 27 countries and 29 populations around the world found a strong correlation between liquid cow's milk and MS prevalence; interestingly, no such correlation was found with cream, butter or cheese (42).

A number of cow's milk proteins have now been shown to be targeted by the immune cells of people with MS (7). Further, injecting the proteins into experimental animals has caused lesions to appear in the central nervous systems of the animals. Other researchers have demonstrated how certain proteins in cow's milk mimic part of myelin oligodendrocyte glycoprotein, the part of myelin thought to initiate the autoimmune reaction in MS (49).

Parkinson's disease
Milk has also been linked to Parkinson's disease (PD). Researchers found that among more than 130,000 American adults followed for nine years, those who consumed the largest amount of dairy foods had an increased risk of developing Parkinson's disease (50). Men with the highest levels of dairy consumption were 60% more likely to develop the disease than those who consumed the least amounts of dairy, particularly milk (50-54). This supports earlier findings about dairy intake and the development of PD: the same authors studied men with high dairy consumption and found that those men had an 80% higher risk. Women with moderate dairy intake were also found to be in the high-risk range for PD.

A study found that Japanese-American men in Honolulu, Hawaii who consumed more than 0.5 litres of milk per day had a 130% higher risk of PD than men who did not drink milk (52). In a study in which a total of 128 participants developed Parkinson's disease, the risk of Parkinson's disease increased as the amount of milk consumed each day rose. Heavy milk drinkers - those who consumed more than 16 ounces (454g) per day - were more than twice as likely to develop Parkinson's disease than non-milk drinkers (52).

Heart disease

Epidemiological evidence suggests that per capita consumption of milk proteins and milk is associated with national mortality rates from heart attack or stroke (55-58), although it does not appear to be associated with the saturated fat consumption.

Milk consumption results in significantly elevated blood levels of IGF-1 in prepubertal and pubertal individuals, as well as young adults, which is associated with acne (59-62).

Not a great food
Cow's milk is not a great food for humans. What I have presented here is just a small fraction of the scientific literature highlighting the problems with milk. Perhaps in the future we will see health warnings on milk containers. Unfortunately, we have been sold a deceptive message for more than 50 years so everyone believes that "milk does a body good".

No other animal on this planet consumes milk beyond infancy or another animal's milk. Despite this, humans are the only animal that suffers from such high rates of chronic illness. To complicate this equation even further, we destroy many of the healthful qualities of milk, including enzymes and antioxidants, by pasteurisation. We then mix the fat and liquid together through homogenisation and we still call it a natural food.

Whatever beneficial qualities milk might have in very small quantities no longer exist when we process them out, or even worse, add sugar and chemical colours to make flavoured milk. It's time to seriously rethink the health wisdom of that glass of milk or poured on your daily cereal and even the whole concept of milk and processed cereal altogether.

Dr Peter Dingle is a researcher, educator and public health advocate. He has a PhD in the field of environmental toxicology and is not a medical doctor.

1. Goldberg and Folta 2002
2. Smith et al. 1995).
3. Helm 2000
4. Monaci et al. 2006
5. Moetini et al. 2000
6. Michaelidoua and Steijns 2006
7. Jelenek 2010
8. Blum 2009
9. Fürstenberger and Senn 2002
10. Francis et al. 2008
11. Edwards et al. 2007
12. Wiley 2005
13. Berkley et al. 2009
14. Daniel 2007).
15. Key et al. 2003
16. Shaneyfelt et al. 2001
17. Ganmaa and Sato 2005
18. Gao et al. 2005
19. Ganmaa et al. 2002
20. Qina et al. 2004
21. Tominaga and Kuroishi 1997
22. Campbell and Campbell 2004
23. Ganmaa et al. 2002
24. Davies et al. 1996
25. Garner et al. 2003
26. Strang et al. 2006
27. Mettlin et al. (1990
28. Gaskill et al. 1979
29. Stocks 1970
30. La Vecchia 1993
31. Le et al. 1986
32. Ursinl et al. 1990
33. Larsson et al. 2004).
34. Harrison and Honeyman 1999
35. Scott 1990
36. Elliot and Laugesen 2003
37. Goldberg and Folta 2002
38. Laugesen and Elliot 2003
39. Wasmuth et al. 1999
40. Thorsdottir et al. 2000
41. Padberg et al. 1999
42. Elliot et al. 1998
43. Tailford et al. 2003
44. Butcher 1976
45. Malosse et al. 1992
46. Malosse et al. 1993
47. Winer et al. 2001
48. Stefferl et al. 2000
49. Guggenmos 2004
50. Chen et al. 2002
51. Norton 2007
52. Park et al. 2005
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54. Chen et al. 2007
55. Venn et al. 2005
56. McLachlan 2000
57. Popham et al. 1983
58. Seely 1981).
59. Schmitz and Melnik 2009
60. Batya et al. 2010
61. Danby 2008
62. Adebamowo et al. 2008

Peter Dingle

Dr Peter Dingle (PhD) has spent the past 30 years as a researcher, educator, author and advocate for a common sense approach to health and wellbeing. He has a PhD in the field of environmental toxicology and is not a medical doctor. He is Australia’s leading motivational health speaker and has 14 books in publication.