Ask the doctors: Dangers of raw milk arise from bacteria

Q: We might start buying raw milk from a family farm in our area. It seems safe because they have only two cows and test the milk for bacteria. But when I told my dad, he said raw milk is always risky. Is that true?

A: The term “raw milk” refers to milk that does not undergo pasteurization. That's the process of heating milk to the high temperatures needed to kill bacteria and other microbes. The safety of raw milk is a hot-button issue with deeply held opinions, both pro and con. On one side are public health officials, including the Centers for Disease Control and Prevention, who warn of the potential dangers of milk that has not been sufficiently processed to kill bacteria. On the other side are advocates, often impassioned, who say that modern-day dairy practices have removed the risks associated with raw milk and that pasteurization strips the milk of vital nutrients.

The potential dangers of raw milk arise from bacteria including salmonella, E. coli, listeria and brucella. They can make anyone ill, but are particularly dangerous to young children, older adults and individuals with weakened immune systems. Diseases known to be caused by contaminated raw milk include tuberculosis, diphtheria, listeriosis, Guillain-Barre syndrome and typhoid fever.

Microbes may come directly from the animal, or they can contaminate milk in the series of steps that take place as it makes its way to the consumer. This includes during milking, packaging and storage. Milk of any kind is an excellent medium for bacterial growth and requires vigilant hygiene to keep it safe. According to the CDC, improper handling of milk leads to nearly triple the hospitalizations of any other type of foodborne illness.

Advocates of raw milk point to the numerous precautions taken by modern dairy farmers who produce and sell it. This includes maintaining the health of the animals, hygienic milking conditions and practices, safety practices during packaging and transport, and extensive testing for the presence of bacteria. However, the CDC states that testing does not consistently detect low levels of microbial contamination, which can make someone sick. The agency also points to data that show some people have become seriously ill from raw milk that was procured from dairies that do regular testing.

At this time, the sale of raw milk is subject to a patchwork of laws. The FDA banned the sale or distribution of raw milk across state lines in 1987. However, the states themselves are free to allow and regulate the sale of the product within their own borders. Today, 30 states allow the sale and distribution of raw milk, and 20 states prohibit it. Whether it is legally available in your area, and the specific venues where you can purchase it, depend on your state's particular laws. (Editor’s note: Raw milk can be sold in Illinois directly from the dairy farm only.)

In our own practices, if the topic of raw milk arises, we share both sides of the issue with our patients. And when it comes to our advice, our approach is to urge patients to consider easing away from cow's milk altogether and to consider plant-based products instead.

Cold plunge one form of whole-body cryotherapy

Q: It's a tradition in my husband's family to start the new year with a dip in the ocean. We live in Maryland, so that means it's freezing cold. I see on social media that doing a cold plunge is now a craze. Is it true what they're saying, that it's good for you?

A: Enthusiasts on TikTok, where cold plunge videos are amassing millions of views, are advocating a practice that dates back thousands of years. The use of cold as a therapeutic agent is referenced in texts left behind by the ancient Egyptians and cited as beneficial by the ancient Greeks.

The cold plunge is just as it sounds: It's immersing yourself in icy water. How long the dip lasts, how often it is done and how cold the water should be varies. The common denominator is the idea that subjecting your body to a sudden and prolonged change in temperature confers physical and mental health benefits.

The cold plunge falls into a treatment category known as whole-body cryotherapy. Depending on the approach, it involves the application of ice, cold air or cold water. Proponents cite a vast and varied list of benefits. These include pain relief, improved exercise recovery, better sleep, sharper focus, improved mood, lower levels of inflammation, enhanced immune function, improved insulin sensitivity, better tolerance of mental and emotional stress, and boosted metabolism. Data definitely support the idea that cold exposure can confer health benefits. However, research into the practice is mixed, and cold plunge skeptics will also find studies to cite.

An intriguing area of inquiry in cryotherapy is its potential effect on brown fat. This is a type of fat the body uses to maintain body temperature by breaking down fat and blood glucose, each a welcome metabolic action. The link to the cold plunge? Brown fat is activated by cold temperatures.

Anyone who wants to try a cold-water therapy should ease into it. Some enthusiasts say icy showers are a good way to begin. For full-body immersion, start with brief, controlled exposures of just 10 to 20 seconds. If longer dips are the goal, get there gradually.

It's also important to know that a cold plunge can have adverse effects. When suddenly immersed in cold water, your body scrambles to preserve core temperature. Blood vessels constrict, the heart races, blood pressure shoots up and you begin to hyperventilate. None of this is safe for people with heart conditions, poor circulation and certain other health issues. And because water conducts heat from the body far more quickly than air, it doesn't take long for core body temperature to drop. As the body directs blood flow to protect vital organs, strength and coordination are lost.

All of this makes it a good idea to check in with your health care provider before giving the cold plunge a shot. And while this may seem like a no-brainer, we feel compelled to say, please, don't ever go swimming in icy water alone.

• Dr. Eve Glazier is an internist and associate professor of medicine at UCLA Health. Dr. Elizabeth Ko is an internist and assistant professor of medicine at UCLA Health. Send your questions to askthedoctors@mednet.ucla.edu.

© 2024 UCLA Health. Distributed by Andrews McMeel Syndication