Consumption of breast milk sold online under the claims of clean and healthy can lead to serious health problems such as erectile dysfunction, cancer, hepatitis B and C, HIV and syphilis, British experts say. A study conducted by researchers at the Queen Mary University of London shows that most of the milk was unpasteurized and carried harmful germs.

The study, published on Wednesday in the Journal of the Royal Society of Medicine, stated that women selling breast milk online fail to use proper sanitization methods, use unsterilized equipment to store milk, and prolong the storage and transportation of milk, which can expose consumers to bacterial food-borne diseases.

According to the study, 93 percent of breast milk sold online has observable levels of bacteria. 

"While many online mums claim they have been tested for viruses during pregnancy, many do not realize that serological screening needs to be undertaken regularly," Sarah Steele of the Global Health and Policy Unit, Queen Mary University of London, and the study's lead author, said in a statement. "Sexual and other activities in the postpartum period may expose the woman expressing to viruses that they may unwittingly pass on to consumers of the milk."

Alcohol, drugs (both prescription and illicit), tobacco and caffeine goes into the milk sold online alongside other environmental contaminants, such as chemicals and toxins, the researchers said. They also urged health professionals and regulators to issue public guidance for consumers to warn them about the risks of buying breast milk online.