Panel 5 - Milk and dairy in human nutrition
Humans are the only free living animals that consume the milk of other species, and do so even beyond weaning. Three quarters of adults in the world are lactose intolerant, that is, lack the enzyme (lactase) needed to break down the sugar found in milk (lactose); this makes them unable to digest milk properly and leads to more or less serious digestive disorders.
The nutritional profile of milk is similar to that of meat. Both foods have similar amounts of saturated fat and protein. Like meat, milk completely lacks the fiber and hundreds of phytochemicals which are contained in plant-based foods, and which have been found to be protective against degenerative diseases such as coronary heart disease and cancers. [Goodland2001]
The production of meat and the production of milk are strongly linked; one can be called a by-product of the other. The effects on health of an increased consumption of milk and dairy products are similar to those of an increased consumption of other animal products, such as meat and suet. While low-fat dairy products might sound healthier, the fat removed in the manufacturing of such products is never wasted, but is consumed as butter, cream, ice cream, or processed foods, so the net positive effect on public health is zero. Scientific evidence is now available of the fact that dairy products have no benefits which are not better obtainable elsewhere, and that their consumption poses major risks that contribute to morbidity and mortality. [Goodland2001]
It is commonly believed that the calcium content of cow's milk makes it an essential food to prevent brittle bones, particularly for children. The problem is that even though milk may be an efficient way to get calcium from food, it also comes with a lot of negatives, particularly a very high saturated fat content. As Professor Walter Willett points out, 'drinking three glasses a day would be the equivalent of eating twelve strips of bacon or a Big Mac and an order of fries'. [Willet2001]
Moreover, keeping your bones strong depends more on preventing loss of calcium than on boosting calcium intake. We regularly lose calcium from our bloodstream through urine, sweat, and feces; this calcium then has to be replaced with calcium obtained from foods or drawn from our bones. One major factor in calcium depletion are high-protein diets, which cause more calcium to be lost through the urine. Of course diets rich in meat and dairy products tend to exceed by far the recommended protein levels. [PCRM1999] Also, protein from animal products is much more likely to cause calcium loss than protein from plant foods, and milk and dairies are very rich in animal proteins, thus, even if they are rich in calcium, too, the overall balance is often negative, and causes calcium depletion in the bones.
The high prevalence of osteoporosis in countries where dairy consumption is high is a further indicator of its ineffectiveness in countering brittle bones. The World Health Organisation/Food and Agriculture Organisation's summary of the latest evidence on osteoporosis states that for most people there appears to be no correlation between increased calcium intake and a decreased risk of bone fractures. The dietary recommendation from the WHO/FAO for osteoporosis is to eat more fruit and vegetables rather than rely on dairy foods to ensure good bone health. [WHO/FAO2002]
Goodland R., The Westernization of Diets - The Assessment of Impacts in Developing countries - with special reference to China, DRAFT, 2001
Physician Committee for Responsible Medicine, PCRM. Vegetarian Starter Kit, PCRM, 1999
WHO/FAO, Diet, nutrition, and the prevention of chronic disease. Report of the Joint WHO/FAO expert consultation, 26 April 2002.
Walter C. Willett, Eat, Drink and Be Healthy, The Harvard Medical School Guide to Healthy Eating, Simon & Schuster, 2001