Diagnosed with tuberculosis of the bowel in 1920, Winifred Dye Britton was prescribed a strict diet of raw milk and eggs and plenty of fresh air by her Oregon doctor. It worked.

Kimberly Hartke said her great grandmother would have died without the health benefits of the Milk Diet, a popular treatment reputed to cure everything from arthritis, infertility, indigestion to ulcers and congestive heart failure.

"It literally re-grew her colon and gave her fresh blood and allowed her body to heal. If she didn't have it she wouldn't make it."

Hartke works for the Weston A. Price Foundation, America's largest raw milk advocacy group based in Washington, DC. She says many natural remedies like drinking raw milk fell by the wayside in the wake of modern medicine and pharmaceuticals, but many people support her organization because they still believe in its health benefits.

"This food can literally be a lifeline to people," she said.

But Britton's story illustrates the much contested question of whether raw dairy has any proven health benefits and if they outweigh potential risks.

For believers, unpasteurized milk is a magic elixir responsible for boosting the immune system and curing many ailments, including irritable bowel syndrome, lactose intolerance, asthma and eczema. But to health authorities, drinking raw milk is inherently dangerous, possibly lethal - and should be avoided at all costs.

"From a public health standpoint, it's all risk and no benefit," Dr. John Carlsey, a public health officer with Vancouver Coastal Health, told ctvbc.ca.

Canada made the sale of raw milk illegal in 1991, saying that heat treatment, or pasteurization, is the only way to destroy potential pathogens in milk that could cause potentially deadly outbreaks of E. coli.

The agency says a court decision this week upholding the legality of cow-share co-ops in Ontario will not make it reexamine its policy.

B.C.'s provincial health officer, Dr. Perry Kendall, told CTV News raw milk needs to remain illegal to protect people from an unnecessary health risk.

"A number of illnesses can pass relatively easily from the cow into the raw milk that can multiply in the raw milk and they can cause serious illness and even death in the people that drink it -- particularly in people like children that have compromised immune systems."

Health claims and the scientific evidence

Raw milk enthusiasts often say raw milk rebuilds immune systems and improves overall digestive ability. But how much scientific truth is behind these claims?

Robert D. Ralyea, a food scientist with Cornell University, told ctvbc.ca many of the health benefits are only anecdotal.

"Probably, to some degree, raw milk helps your immune system because there are things you have to fight off. But if you have a compromised immune system, it's not going to help you," Ralyea said from his New York lab.

Ralyea said many scientific studies cited in favour of raw milk date back to the 1920s and 1930s, something he feels may make them outdated.

But Mark McAfee, the owner and CEO of California's largest raw milk dairy, says the age of the science doesn't make it any less valid.

"Doctors in the '20s and '30s knew that raw milk could help a number of conditions. And that was a long time ago. But science didn't change. Gravity didn't change. Just because it was discovered 75 years ago doesn't make it less correct or accurate."

Some recent claims do hold significant scientific credence, including research that suggests drinking raw milk could ease lactose intolerance.

A recent study supported by a group of cowshare dairy farmers in Michigan found that 82 percent of people who had a professional diagnosis of lactose intolerance, including some of the dairies’ customers, could drink raw milk and not suffer from the symptoms they experienced after drinking pasteurized milk.

Ontario farmer Michael Schmidt told ctvbc.ca he's seen proof of this firsthand.

"Eighty per cent of our customers can't drink regular milk," he said.

"These are people who struggle with their children because they can't digest regular milk. These people are telling me with tears in their eyes, 'It's just such a blessing raw milk exists.'"

The role of probiotics

Another common health claim made by raw milk enthusiast is the benefit of probiotics in the liquid itself. First seen in food dating back to ancient times, the live bacteria - which acts similar to enzymes found in the human gut - is making a resurgence. The World Health Organization supports probiotic's healing qualities and spending on probiotic supplements and products tripled from 1994 to 2003 in the U.S.

B.C. farmer Alice Jongerden says many people come to her co-op for milk because of a probiotic effect they say makes milk easier to digest.

"All of the beneficial bacteria coats the gut. It keeps you healthy and makes every difference in life."

Dr. Perry Kendall concedes probiotic bacteria in raw milk can be beneficial to the person drinking it - but can be achieved in other ways without fear of illness.

"You can get those from a number of other sources without the risks of getting salmonella, E. coli or Staphylococcus disease or Listeria."

Despite some promising evidence in 2006 to support the use of probiotics to treat irritable bowel syndrome - or IBS - Ralyea of Cornell University said more scientific evidence is needed to prove the "probiotic effect."

"Although beneficial bacteria could be present in raw milk, the strains are unstable and the number present in freshly harvested milk are too low to promote human health or to out-compete pathogen growth."

Meaning helpful bacteria might make raw milk easier to digest but those same bacteria could be pathogenic - and could make you sick.

Cornell published a position statement two years ago examining the latest scientific studies on unpasteurized milk. Like Canadian health agencies, it concluded the perceived benefits of drinking raw milk do not outweigh the risks associated with exposure to food borne pathogens - especially for pregnant women, infants, the elderly and people with compromised immune systems.

A recent conference by the National Center for Complementary and Alternative Medicine (NCCAM) and convened by the American Society for Microbiology echoed this conclusion, noting any beneficial effect was usually low and more research is needed.

Ignoring the evidence?

Members of the raw dairy world accuse Canadian and American health authorities of ignoring new science about the health benefits of raw milk and otherwise refusing to do any research of their own.

But there are encouraging and recent studies highlighting potential benefits of raw dairy.

A highly quoted 2006 European study known as Parsifal followed almost 15,000 kids in five countries and found that the consumption of raw or farm milk may offer protection against asthma and atopic allergies like eczema.

The authors of the Parsifal study found kids who consumed raw milk in the first year of life strongly and consistently reported fewer instances of asthma, allergy and eczema through their childhood. However, the study stopped short of recommending raw milk as a preventative measure for these diseases.

Mark McAfee, who created the first international safety standards for raw milk, says North American regulators will ignore positive scientific evidence like the Parsifal study because there is no financial incentive.

"The FDA refuses to accept new science in Europe because they don't want to spend the money to peer review it here."

The structure of North American health agencies makes it impossible for anyone to make health claims about raw milk because governments do not assign any value to food for healing or medicinal purposes, McAfee said.

"They say only drugs can cure disease or illness. Any claims that food could do this would be illegal. You could be indicted."

A lack of financial incentive could work against raw milk in more ways than one, McAfee says.

"Nobody in their right mind is going to spend millions of dollars to research and make a medical claim that raw milk helps the immune system. There's no product to make a stock value improve."

Frustrated with a lack of new science, dairy advocates are beginning to take matters into their own hands and doing their own research.

Ontario farmer Michael Schmidt interviewed his 600 shareholders about their experiences with raw milk to submit to Health Canada and to submit as evidence at his trial in 2009. It was dismissed.

"Health agencies are intentionally ignoring the science," he said.

"These are incredible studies but if they accepted it, their whole house of cards would fall and they would have to justify raw milk."

As for B.C. farmer Alice Jongerden, who will begin fighting a permanent court injunction by health authorities on Feb. 2, she says the scientific evidence is in the milk itself.

"It comes down to this -- God made it. Why do we have to change something that's been designed perfectly already?"

Come back to CTV British Columbia on Jan. 25 for the third installment of our five-part series on raw milk. Should this milk be legal? examines why Canada is the only G8 country where raw milk is outlawed.