Milk is well known as a great dietary source of protein and calcium, not to mention an indispensable companion to cookies. But "nature's perfect food," a label given to milk over time by a variety of boosters, including consumer activists, government nutritionists and the American Dairy Council, has become a great source of controversy, too. The long-running dispute over whether milk, both from cows and goats, should be consumed in raw or pasteurized form—an argument more than a century old—has heated up in the last five years, according to Bill Marler, a Washington State lawyer who takes raw milk and other food poisoning cases.

A bumper crop of recent illness related to raw milk accentuates the problem. Last month, at least 30 people, including two children, tested positive for strains of campylobacter and Escherichia coli bacteria traced to raw (nonpasteurized) goat milk. In June five people in Minnesota were diagnosed with E. coli traced to raw cow's milk from a local dairy. One, a toddler, was hospitalized after he developed hemolytic uremic syndrome, a type of kidney failure that is a potentially deadly E. coli complication.

They are hardly isolated cases. In fact, there have already been more reports of raw milk-related illness outbreaks this year in the U.S. than in any of the past five years.

Such outbreaks are largely preventable if milk is pasteurized, says Robert Tauxe, deputy director of the Division of Foodborne, Bacterial and Mycotic Diseases at the U.S. Centers for Disease Control (CDC). The process (known as high temperature, short time (HTST) pasteurization) was invented more than a century ago and relies on heat at least 72 degrees Celsius for 15 seconds to kill the stew of E. coli, campylobacter, Listeria, salmonella and other microbes that may lurk in milk that comes straight from a cow or goat. Medical experts consider pasteurization as one of the major breakthroughs in public health history. "A triumph," Tauxe adds.

Keeping it real
Raw milk proponents, including The Weston A. Price Foundation, deny its dangers and praise its superior flavor. They believe raw milk obtained from healthy, pasture-fed animals strengthens the immune system in a manner similar to human breast milk and that it cures digestive tract conditions such as Crohn's disease. Sally Fallon Morell, the foundation's president and founder of the Campaign for Real Milk, disputes the claims of raw milk-related illness. "We have analyzed those reports, and 95 percent should go in the trash can because they're biased," she says. "The pasteurization argument is based on 40-year-old science."

Raw milk advocates also claim that pasteurization destroys key nutrients. "Real milk contains a complex system of enzymes, fats, carbohydrates and fragile proteins that are wonders of the microscopic world," Fallon Morell says. "They are destroyed with rapid heating."

That assertion is debatable. As with any cooking process, pasteurization causes some chemical change, says Jennifer Nelson, a nutritionist with the Mayo Clinic in Rochester, Minn., although she says that nutrition researchers are still testing to see if nutrients, enzymes and other health-related components are significantly altered. Whatever the nutritional change, Nelson cautions, "Raw milk can carry pathogens that can cause illness and death." Certain high risk groups should never drink raw milk: infants, growing children, the elderly and people who are immune compromised because their immune systems may not be strong enough to fight off the pathogens often found in raw milk, she adds.

Given the number of disease outbreaks related to raw milk, one might expect the demand for raw milk to dry up. Not so—in fact, demand for raw milk has risen faster than cream in a milk bottle, commanding prices as high as $10 per gallon. Despite the warnings of public health officials, including the Web site Real Raw Milk Facts, raw milk has become a national cause célèbre, and dairymen who sell it have become local folk heroes.

"It's a political issue," Fallon Morell says. "It's also a health, small farm and economic issue. I'm not advocating that we all go back and live on farms, but the pendulum has gone too far in the direction of industry. What we need [are] small farms with Space Age technology."

Those watching from the sidelines wonder if opponents can find common (and safer) ground. Food journalists as well as people who comment in online discussions on the topic often suggest that drinking raw milk is a personal choice that cannot hurt anyone but the person who drinks it. Tauxe disagrees, adding, "If a child comes to a day care center with E. coli, it can be passed to your child, spread through feces in diapers."

No Germs, Less Taste
It seems like some new technology might have come along by now, an alternative to HTST pasteurization, that would make milk safe without delivering what some people think is an inferior product with less taste and nutrition. Yet, few alternatives have emerged since the days of Pasteur, according to University of Minnesota (U.M.) associate professor of veterinary public health, Jeff Bender. Each of the available alternatives has a downside: For example, some believe that low-temperature pasteurization (also known as batch processing) yields a tastier product. This process heats the milk up to a minimum temperature of 62 degrees C where it remains for 30 minutes, thereby taking longer than standard HTST pasteurization.

Another example, irradiation—sometimes called "cold pasteurization"—uses ionizing radiation from electrically charged particles (such as x-rays and gamma rays) to kill harmful bacteria and other organisms in meat, poultry, seafood and spices. But, Bender says, irradiation changes the taste of milk. He also says that high-pressure processing methods, whereby food is subjected to pressures of 3,500 to 7,000 kilograms per square centimeter to kill microorganisms, work well in solid foods such as ham but are far too expensive to use on liquids.

Bombarding the milk with sound waves in a process called sonication may hold potential as an alternative. Sonication heats milk to a temperature well below what the U.S. Food and Drug Administration requires for pasteurization, killing the microbes without causing milk proteins to denature and hence alter the flavor, according to investigators from Louisiana State University in Baton Rouge, who at the Institute of Food Technologists' annual meeting in July presented data showing that their team used the process to knock out coliform bacteria. In addition, they said, sonication takes roughly half as much energy as high-temperature pasteurization.

Sonication may be the way forward but, for the time being, high-temperature, short-time pasteurization remains the most proven method for zapping the most germs from milk while maintaining quality, speed, and lower cost. Says Bender, who is also director of U.M.'s Center for Animal Health and Food Safety and himself a farmer, "After 100-plus years, there is still no better alternative."

Ultimately, the demand for raw milk appears to be as much an issue of personal freedom and the desire to obtain food directly from small farms as it one of nutrition. Yet no matter where the milk comes from or how clean the dairy, raw milk still poses a danger, Tauxe says. "Animals and bacteria are natural companions," he adds. "Normal-looking and tasting milk from a healthy cow can still be contaminated—even in the udder, before the milk leaves the cow."

For people who want to more closely connect with small farms, Tauxe suggests seeking out local artisanal dairy producers who pasteurize. "It's not the size of the farm," he says, "it's the temperature of the milk."