Mary Cronin grew up drinking unpasteurized milk. Her parents, natural foods enthusiasts, believed raw milk was healthier, and it could be legally purchased in Connecticut, where they lived.

When Cronin, now living in Colorado, became pregnant with her son, Jack, she sought out a source for raw milk, which was not sold in Colorado stores.

“When you have a baby, it’s a really good incentive to do what’s best for you,” she says.

Cronin is among a small but growing number of people who are seeking raw milk for what they believe are its healthful properties. Advocates say pasteurization – in which milk is heated, generally to 161 degrees for 15 seconds – kills enzymes, vitamins and beneficial bacteria in milk and makes it more difficult to digest. They say milk is the most healthful when it is closest to its natural state, right out of the cow, and that the naturally occurring enzymes in milk make it possible for those who are lactose-intolerant to digest it.

Drinking unpasteurized milk is highly controversial, however, since raw milk can carry several dangerous pathogens, including salmonella, camphylobacter, listeria and brucella, which causes brucellosis in cows and undulant fever in humans.

The Food and Drug Administration, which does not recommend drinking raw milk, says about 300 people got sick from drinking raw milk or eating cheese made from raw milk in 2001, and about 200 were sickened in 2002, the latest years for which figures are available.

Mary Cronin, seen here with her 5-month old son, Jack Cronin Yeager, drinks raw milk from Guidestone farm in Loveland. Guidestone farms sells raw milk that supporters say contains enzymes that makes milk digestible for anyone. Opponents say drinking raw milk can be dangerous.

Many health professionals feel strongly that raw milk poses an unacceptable danger.

“I don’t see an upside,” says Bonnie Jortberg, a senior research associate at the University of Colorado Health Sciences Center.

Raw milk sales are illegal in many states, though Kansas permits “on-farm” retail sales, and as of 1987, FDA regulations forbid crossing state lines with raw milk. Even many of those who believe in the health properties of raw milk do not believe pasteurization should be discontinued.

“The way our food system is set up, it’s essential that milk gets pasteurized,” says David Lynch, owner of the Guidestone Farm in Loveland, Colo., which offers cow shares as well as shares in other agricultural products.

Lynch, who helped lead the fight to get Colorado’s raw milk law passed, says milk is highly perishable, and unpasteurized milk doesn’t have a long enough shelf life to be sold in grocery stores. Additionally, the milk in cartons may come from more than one cow, making tracing problems much more difficult.

“You don’t know who produced it,” he says.