Once a staple in our kitchens, milk has become a controversial substance in just a few years, fuelling recent debate. But its rehabilitation seems to be well and truly underway. A new international study now suggests that drinking milk is not harmful to your health .
Allergies, digestive problems, diabetes, cholesterol, even cancer: the list of the evils pinned on significant, regular consumption of milk is getting longer and longer over the past few years. Studies and debates have been successively pointing the finger at one of breakfast's former star ingredients, whose sales nevertheless jumped in the US in 2020, during the first months of the pandemic.
Several teams of scientists, from the University of Reading, the University of South Australia and University College London, have taken a serious look at the subject, conducting a meta-analysis of existing data on a large sample of over 1.9 million people. The researchers chose to take a genetic approach to milk consumption by examining a variation in the lactase gene associated with the digestion of milk sugars, known as lactose. This allowed them to identify people who consumed high amounts of milk.
Published in the International Journal of Obesity , the study reveals that people who regularly drink milk, and in significant quantities, have lower levels of good and bad cholesterol. This was observed even though the participants' body mass index (BMI) was higher than that of those who did not drink milk. The analysis also shows a lower risk of coronary heart disease (-14%) in people who regularly consume milk.
"All of this suggests that reducing the intake of milk might not be necessary for preventing cardiovascular diseases," commented Vimal Karani from the University of Reading, one of the main study authors.
The researchers note that the study did not find "strong evidence" for an association between high milk consumption and increased likelihood of diabetes. It also failed to identify the mechanism that leads to lower cholesterol levels in high milk consumers.
"The study certainly shows that milk consumption is not a significant issue for cardiovascular disease risk even though there was a small rise in BMI and body fat among milk drinkers. What we do note in the study is that it remains unclear whether it is the fat content in dairy products that is contributing to the lower cholesterol levels or it is due to an unknown 'milk factor'," concluded Professor Karani.