Lactose study finds raw milk no easier to digest

DRESDEN, Ont. — Raw milk is not an answer to lactose intolerance, according to a paper published in the March-April edition of Annals of Family Medicine.

“Raw milk failed to reduce lactose malabsorption or lactose intolerance symptoms compared with pasteurized milk among adults positive for lactose malabsorption,” the paper’s authors concluded.

“These results do not support widespread anecdotal claims that raw milk reduces the symptoms of lactose intolerance.” 

Researchers at Stanford University’s School of Medicine, who wrote the paper, believe the study is the first randomized controlled trial examining the effect of raw milk on lactose intolerance.

A group of 63 people claiming lactose intolerance were screened using a hydrogen breath test. Just 27 tested positive for the problem and of that number, 16 agreed to participate in the study.

The participants received organic raw milk, organic pasteurized milk and a soy drink over the course of the study. 

A sugar-free vanilla flavouring was used to disguise the taste of what they were drinking.


The hydrogen breath test was used again as a measure of lactose intolerance. An increase in hydrogen production corresponds to the severity of the problem.

Ontario raw milk advocate Michael Schmidt said he is friends with the California dairy farmer who supplied the raw milk. Schmidt said the study was “highly flawed and misguided.”

The hydrogen breath test is an inadequate measure, he said. A better way to evaluate the lactose intolerance question would be to conduct a field study involving raw milk drinkers.

The authors said there were several limitations to the study, including the small sample size and the limited amount of time — eight days — that participants were provided with raw milk.

Replication of the findings in a larger scale would strengthen the conclusion, they said.

Other health claims related to raw milk are plausible, though anecdotal, they added.


  • mike grim

    “More than 400 people who said they suffered digestion problems from drinking milk expressed interest in participating in the study. Out of 63 people who were ultimately tested, only 27 passed the hydrogen test for clinical lactose intolerance. Of those 27 qualifiers, 11 chose to drop out of the study when they learned they would be asked to drink milk for several weeks. That left behind the relatively small sample size of 16 lactose-intolerant participants.”

    “Lactose malabsorption represents a well-known cause of abdominal symptoms although only some lactose malabsorbers are also intolerants.”

    “PURPOSE – This pilot study aimed to determine whether raw milk reduces lactose malabsorption and/or lactose intolerance symptoms relative to pasteurized milk.”

    This study only looked at 16 lactose malabsorbers and ignored over 400 lactose intolerants. What happened to the “and/or lactose intolerance symptoms”? Aren’t they what we are really talking about? This study never addressed it’s primary objective. These researchers took the money and then arbitrary decided to redefine the very purpose of the study.

  • Besides, Lactose is not the most important part of raw milk. We can get calories anywhere. And they never said what the lactose fermented into for these lactose-malabsorbers. Isn’t fermentation just another form digestion?