science 5.8.2016 10:19

Slovenian researchers prove bovine milk is not harmful to health

Ljubljana, 5 August - The researchers from the Veterinary Faculty of Ljubljana have proved bovine milk containing natural estrogen is not harmful to health, said the American Dairy Science Association. The results of the study have dispelled some of the doubts about milk.

Podpeč v Dobrepolju, kmetija Jakopič.
Svetovni dan kmetic.
Kmetica, mleko in mlekarstvo.
Foto: Tamino Petelinšek/STA

Because estrogen in food is known as being harmful to human health, the Slovenian researchers tried to determine the effect of various doses of estrogen on blood hormone levels in mice.

The aim of the study was to evaluate whether exposure to known doses of estrogen from bovine milk could affect blood hormone levels in mice and influence their reproductive organs. Mice received higher concentrations of estrogen, which did not affect their health.

The researchers only noticed changes in the group of mice where the concentration exceeded the physiological concentration of milk estrogens by 1,000 times, which is extremely unlikely in native cow milk.

The levels of estrogen in bovine milk are higher when the cow is pregnant, with milk from cows in the third trimester of pregnancy containing up to 20 times more estrogens than milk from non-pregnant cows.

"The results of our study show that estrogen in milk is not harmful to human health, even when the cow is pregnant. The hormone levels in milk are too low to have any kind of biological effect on the users," explained Gregor Majdič, the head of Centre of Animal Genomics at the Ljubljana Veterinary Faculty.

The results of the study were recently published in the Journal of Dairy Science in America.