Claim No. 2: Dairy products are beneficial for heart health despite raising cholesterol.
The "compelling new research" indicating that "regular milk drinkers do not increase their risk of heart disease" refers to the study by Andy Ness and others published last year entitled "Milk, coronary heart disease and mortality." Like the study by Willett cited earlier, this study measured some aspects of diet and lifestyle and observed subsequent mortality but it involved less than a tenth of the number of people in Willett's study.The authors observed a statistically significant reduction in deaths from heart disease with increased consumption of milk as a drink (11% for the medium milk group and 32% for the high milk group) before adjustment for risk factors, other than age. This relationship remained largely unchanged after adjustment for other risk factors, but was found to have a 1 in 10 chance of being a random observation - in other words it ceased to be statistically significant.
On the other hand, in Hu and Willett's study of US nurses, the fully adjusted risk of heart disease in those consuming two glasses of whole milk per day was 67% higher than for those consuming no whole milk, with less than a 1 in 10,000 chance that the increased risk was a random observation. This study observed no significant effect from skimmed milk.
Both studies are subject to the criticism that it is difficult to adjust for all related characteristics of individuals freely choosing their own diet and lifestyle. It is even more difficult to persuade people to make long-term changes to their diet according to specific instructions, so observational studies such as those cited are often the best evidence available. However, this is not the case for milk and heart disease.
There was a common but misguided belief in the 1950s that high dairy ("Sippy") diets were good for ulcers. Some doctors assigned most of their ulcer patients to high dairy diets while others made little use of such diets. Thus a unique experiment on the effect of assigning individuals to high dairy consumption was created.
A 1960 study on the Sippy diet compared mortality in ulcer patients in the UK and USA depending on whether they had been assigned to the "Sippy" diet or not. Ulcer patients on the Sippy diet were compared both with ulcer patients on other diets and with other patients in terms of the percentage showing heart attacks (myocardial infarction) on autopsy. The results were striking: In the UK the chance of the differences between the Sippy groups and each of the other groups being a random finding was less than 1 in 20 and in the USA it was less than 1 in 100. The study thus provides uniquely strong evidence that high dairy intake substantially increases risk of dying from a heart attack.
The dairy industry also advances two indirect arguments for milk being protective due to non-fat components, namely calcium and B12.
There is good evidence that increases in calcium intake work with increases in potassium and decreases in sodium to reduce blood pressure and reduce risk of stroke and heart disease. As noted above, a healthy vegan diet provides ample calcium without the dangerous saturated fat that goes with it in dairy products.
Milk is also a source of B12 and adequate B12 is essential to avoid elevated levels of homocysteine - a major risk factor for heart disease and overall mortality. Most nonhuman primates get enough B12 from plant foods contaminated with soil and insects. Modern vegans spare the insects and avoid the potential ill effects of contaminated soil and are therefore advised to get at least three micrograms of B12 from fortified foods or supplements daily. This, along with plentiful folate and B6 from green leafy vegetables and other plant foods, is sufficient to minimise homocysteine levels.
Once again, a diet following Vegan Society guidelines provides everything humans need for health. Adding dairy products with their accompanying saturated fat offers only disadvantages in terms of health.
Claim No. 3: Dairy products don't actually raise cholesterol anyway.
The first two claims were flimsy and unsubstantiated but this claim moves even further into the realms of fantasy. The US Dairy Council Handbook provides 178 references in the chapter on "Dairy Foods and Cardiovascular Health" and highlights a 1977 study by Howard and Marks suggesting that milk consumption causes a significant drop in cholesterol. It also includes several other studies carried out around that time. Unsurprisingly, it completely ignores a later paper by Howard and Marks which states:Roberts et al. report that they can find no evidence that milk contains a cholesterol-lowering factor as previously proposed by us. After reviewing their evidence, our other published work, and more recent unpublished results, we agree that such is indeed the case.
The handbook also fails to mention the paper by Roberts et al. which shows a 9% increase in cholesterol with one litre of whole milk per day: to lose one key reference could be considered an accident, to lose two is (at best) carelessness.
Conclusion
The addition of dairy products to a diet based on Vegan Society recommendations will significantly undermine health. The dairy industry is indulging in wishful thinking and selective citation and should either- stop recycling fat from low fat dairy products back into the food supply, or
- stop promoting dairy foods as healthy, or
- show that we have got it completely wrong.
(published with permission in writing from:http://www.vegansociety.com/)
