Milk, whether it comes from seemingly healthy cows, goats or any other animal, can cause serious health problems, including death, if it has not been pasteurized to kill harmful bacteria. This reminder from the Tennessee Department of Health comes following the Centers for Disease Control and Prevention’s announcement regarding hospitalizations and a death from Listeria infections linked to people drinking raw milk from a Pennsylvania dairy.

Tennessee Department of Health Commissioner John Dreyzehner, MD, MPH, suggests those who perceive raw milk as having significant health benefits compared to pasteurized milk should understand the risks.

“Consuming raw milk believing it’s healthier than pasteurized milk is a perilous risk that shakes off the possibility of a range of serious and occasionally fatal illnesses for the individuals and anyone they share it with,” said TDH Commissioner John Dreyzehner, MD, MPH. “Our best choice for healthy, nutritious milk is the pasteurized kind. Even if one believes there are health benefits, an upside, is it worth taking a chance on the downside risk of a serious illness, especially in a child?”

In the last three years, Tennessee has experienced outbreaks associated with drinking raw milk that was not pasteurized. Notably, in 2013, nine residents under the age of nine years were sickened with E.coli O157 bacteria. Five required hospitalization for life-threatening kidney failure. Fortunately, none of the children died.

“The most common arguments we hear about raw milk are ‘pasteurization kills the good parts of milk’ and ‘people have been drinking milk for years without harm,’” said State Epidemiologist Tim Jones, MD.  “In reality, the process of pasteurization is a simple heating process that destroys bacteria without causing significant change to the nutritional benefits of milk. No one really knows how many people may have been harmed by drinking raw milk because the effects can mimic other health issues, and illnesses and deaths in the past may not have been properly linked to the contaminated milk they consumed.”

According the CDC, the most common causes of milk contamination include getting animal feces directly in the milk. Pasteurization effectively kills these bad bacteria. Without this important step, raw milk from even the cleanest, most well-run dairy operations can contain harmful bacteria, viruses and parasites capable of causing serious illness.  These germs do not affect the color, smell or taste of milk, but can cause days of diarrhea, stomach cramping and vomiting.  In some cases, drinking contaminated milk can lead to kidney failure and death.

“The Tennessee Department of Agriculture inspects licensed farms, trucks and plants where raw milk for pasteurization is collected, handled and processed to make certain that safety standards are met and regulations are followed,” said Tennessee Department of Agriculture Dairy Administrator Bill Thompson. “Pasteurization equipment is tested every three months to verify proper operation, and oversight even extends to the manufacture of packaging containers. Periodic testing of raw milk for pasteurization and finished milk and dairy products also helps ensure what you buy at the store is safe and wholesome for you and your family.”

“If you think about where milk comes out of a cow or goat, you know it’s not far where manure comes out,” said John Dunn, DVM, who directs zoonotic disease outbreaks with TDH.  “Even very conscientious cleaning of the udder and care while milking can’t prevent all risks of contamination during the milking process. Pasteurization kills bad bacteria that inadvertently contaminate milk and makes it safe to drink.”

While even the healthiest people can become ill from drinking contaminated raw milk, those at greatest risk for harm are the elderly, young children and people who have weak immune systems including those undergoing treatment for cancer, who have had an organ transplant or who have HIV/AIDS. Young children, who may be fed raw milk by well-intentioned family members, actually have the highest risk for harm and little ability to make a decision about the risk.

The mission of the Tennessee Department of Health is to protect, promote and improve the health and prosperity of people in Tennessee. TDH has facilities in all 95 counties and provides direct services for more than one in five Tennesseans annually as well as indirect services for everyone in the state, including emergency response to health threats, licensure of health professionals, regulation of health care facilities and inspection of food service establishments. Learn more about TDH services and programs at