Dairy products are listed in both UK and US recommendations as one of the top four food groups that make up a ‘well-balanced diet’. Children are encouraged to consume three daily servings of low-fat milk in the US on the basis that it has less calories than full-fat milk. Milk is also recommended because it has a high protein and calcium content.
However, in this month’s Journal of the American Medical Association (Pediatrics) two top nutrition experts, Professors David Ludwig and Walter Willets, question this advice. They point out that research shows either no difference in weight gain, or greater weight gain, in children who opt for low-fat versus full-fat milk.
They also say ‘humans have no nutritional requirement for animal milk, an evolutionarily recent addition to diet.’ They also point out that ‘throughout the world, bone fracture rates tend to be lower in countries that do not consume milk compared to those that do. Moreover, milk consumption does not protect against fracture in adults, according to a recent meta-analysis.’
More concerning is the growing evidence for milk consumption increasing cancer risk, especially of the prostate. They point out that milk raises IGF-1 (insulin-like growth factor) which promotes cancer cell growth. In addition, they point out that ‘modern industrial methods maintain dairy cows in active milk production throughout successive pregnancies, resulting in a milk supply with high levels of reproductive hormones. Consumption of dairy products probably increases the likelihood or severity of prostate cancer, according to a report from the World Cancer Research Foundation in 2007.’ Earlier this year a study in the Journal of Nutrition confirmed that the more dairy a man consumes the greater is their risk of prostate cancer. They found that ‘Skimmed/low-fat milk intake was positively associated with risk of low-grade, early stage, and screen-detected cancers, whereas whole milk intake was associated only with fatal prostate cancer.’ Whole milk intake was associated with doubling the risk of progression from a prostate cancer diagnosis to death. Similarly, a study this year in the Journal of the National Cancer Institute finds that high-fat dairy product intake is associated with higher breast cancer mortality, while low-fat dairy intake was not. While the link between overall dairy intake and breast cancer risk is not as strong as for prostate cancer, the advice to avoid dairy products if you have breast cancer or are at significant risk, still holds true, especially in regard to full-fat dairy products.
Fat-based hormones, such as oestrogens, are going to be more concentrated in full-fat milk and cheeses, while IGF-1, being protein-based, will be more concentrated in low-fat dairy products.
Given that milk is a non-essential food for adults, provided you are eating enough protein from eggs, meat, fish, and vegetarian protein sources such as beans, lentils, nuts and seeds, and enough calcium from these vegetarian protein sources, then I would keep your intake of dairy products to a minimum or avoid it completely.
My book Say No to Cancer gives plenty of advice such as this for massively reducing your risk of all kinds of cancer. Poignantly, as one rather sad fellow, who has just had major surgery plus grueling chemo and radiotherapy, said “I wish I had read this years ago.”