Consuming large amounts of milk increases the risk of premature death

Thanks to its particularly rich nutritional composition (18 of the 22 essential nutrients), milk is still a benchmark food in the prevention of osteoporosis. A recent study published by the British Medical Journal¹ However, it has just been very cold: not only does the milk not reduce the risk of fractures, but in addition, it significantly increases the risk of death.

The incriminated D-galactose

The authors of the study found that drinking too much milk could have unwanted effects due to its rich D-galactose composition. Experimental studies^2-5 have in fact shown that chronic exposure to this compound is harmful to health and leads to premature aging in many animals. Effects have also been observed even in the case of low doses of D-galactose: the latter would cause changes related to aging such as a decrease in the immune response, an increase in oxidative stress, chronic inflammation and increased genetic mutations. Thus, a subcutaneous dose of 100 mg / kg of this compound (which is equivalent to 1 or 2 glasses of milk in humans) for example accelerates the phenomenon of senescence in mice. The repercussions of these phenomena on bone mineral loss⁶ therefore appear to contradict the recommendations for the consumption of milk for the prevention of fractures.

It is in this context that the researchers hypothesized that a large consumption of milk increased the risk of mortality and the occurrence of fractures. So far, no study has come to such a conclusion.^{7, 8}. On the contrary. But for the first time, researchers have separated milk from other dairy products like cheese or yogurts that don’t contain D-galactose and whose anti-inflammatory and probiotic effects are well known.^{9, 10.11}. In addition, other studies^{12, 13.14} showed that unlike milk, fermented milk products were associated with lower cardiovascular risks.

A risk of premature death doubled among heavy consumers

The study involved nearly 100,000 people (the majority of whom were women aged 39 to 74), followed for twenty years. During this period, 15,541 women died and 17,252 presented with a fractured femoral neck, while 10,112 men died and only 5,066 had their femur fractured. The analysis of these facts and the resulting conclusions are spectacular: the risk of death is almost doubled in women who drink 3 glasses of milk or more per day. Each additional glass thus leads to a 15% increase in mortality in women! This risk appears more modest in men since it is only 3%.

Yogurts and cheeses out of the question

The consumption of milk does not seem to improve the risk of fracture either, since for each additional glass of milk, on the contrary, a slight increase in the rate of fractures appears. Researchers have also found a link between milk consumption and the urinary concentration of certain markers of oxidative stress and inflammation, such as 8-iso PGF1α and interleukins 6. What about other dairy products? As the researchers predicted, the latter would be well associated with a reduction in the risk of fractures and death. However, the intervention of confounding factors remains possible; it is therefore advisable not to interpret the results of this study, which is already causing a lot of noise, too quickly.