A total of 16 participants drank three different milks, each over eight days. Lactose intolerant participants each consumed pasteurized milk, raw milk and soy milk (which doesn’t have lactose and served as a control). Participants were randomly assigned the order of milk in unlabeled containers.
The study found little difference between the consumption of the different milks.
No hint of benefit
Christopher Gardner PhD, senior author, said the results were ‘highly consistent.’ He said they were enough to deflate anecdotes that lactose intolerant people find raw milk easier to digest.
People who are lactose intolerant don’t have enough of the enzyme lactase, which breaks down sugar in milk (lactose). This digestion difficulty can cause stomach cramps and diarrhea.
Participants drank one type of milk for eight days, and were tested for lactose on days one and eight. After a break, they repeated the process with a different milk.
Levels of hydrogen in a person’s breath are higher when undigested lactose is present. When the study compared the hydrogen breath test results, it found little difference between the consumption of raw milk and pasteurized milk.
The participants didn’t notice a change in the severity of their symptoms when drinking raw milk compared to pasteurized milk.
“It’s not that there was a trend toward a benefit from raw milk and our study wasn’t big enough to capture it; it’s that there was no hint of any benefit,” said Gardner.
Mark McAfee, chairman of Raw Milk Institute and CEO of Organic Pastures Dairy (a raw milk producer) told DairyReporter.com he does not think the study is valid.
Raw milk contains bacteria which, in the presence of lactose, creates the lactase enzyme, he said. But he claims it takes time for the bacteria to colonize and enzymes to accumulate.
McAfee criticized the small, selective sample size and short duration of the study.
“The study only went for three weeks. Our consumers go a month or two before they see the effects,” he said.
He said the sample size was too small and only made up of people with severe lactose intolerance.
“What we find in the raw milk market is that there is still a very small proportion of people who have difficulty digestion raw milk,” he said. He added most people with milder lactose intolerance can drink raw milk.
“We think this is a study that begs more questions and provides no answers.”
30 – 50m Americans are lactose intolerant , according to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK).
FDA (US Food and Drug Administration) advises consumers not to drink raw milk. It says that all milk, whether raw or pasteurized, contains lactose, and pasteurization does not change the concentration of lactose. It advises that Bifidobacteria in raw milk does not help create lactase.
Source: Annals of Family Medicine
March/April 2014, Vol 12, no 2, P134-141.
“Effect of Raw Milk on Lactose Intolerance: A Randomized Controlled Pilot Study”
Sarah Mummah, Beibei Oelrich, Jessica Hope, Ouyen Vu, Christopher Gardner.