Stanford Study on Raw Milk Digestibility: Conflicting Interpretations

Raw Milk Proponents Question Sample Size, Duration and Study Design

Washington, District of Columbia, UNITED STATES

Washington, DC, March 26, 2014 (GLOBE NEWSWIRE) -- Researchers found little difference between the digestibility of raw versus pasteurized milk, according to a Stanford University study published in the March/April 2014 edition of the Annals of Family Medicine. But raw milk proponents dispute the interpretation of the findings.

The researchers selected participants based on results of an approved medical test for lactose malabsorption--the hydrogen (H2) breath test. According to the researchers, raw milk failed to reduce hydrogen levels, indicating no improvement in lactose malabsorption or intolerance symptoms compared with pasteurized.  The university headlined the findings, "Claim that raw milk reduces lactose intolerance doesn't pass smell test."

The study results are in conflict with the personal experience of many satisfied raw milk drinkers who complain of difficulty digesting pasteurized milk.

Critics of the Stanford study point to flaws in the design, choice of controls and sample size, leading researchers to a false conclusion.

For example, the researchers chose only sixteen individuals, after screening four hundred forty applicants claiming to have problems digesting milk.

Mark McAfee, chairman of the board at the Raw Milk Institute, questions drawing conclusions from such a small sample. "The study actually shows that the H2 breath test is insufficient to diagnose milk sugar digestion problems in 97 percent of the study applicants. Most people are not overtly lactose intolerant but are better described as pasteurization intolerant, something for which medical science may not have an appropriate test."

Critics also questioned the use of soy milk as a control.  According to Sally Fallon Morell, president of the Weston A. Price Foundation, which provided partial funding for the study, "We hear reports that soy milk causes indigestion and flatulence in many people.  Yet, according to the H2test, it is more digestible than both raw and pasteurized milk.  The study design was severely flawed, and not appropriate for measuring overall milk digestibility."

The Raw Milk Institute, which also provided funding for the research, claims the brevity of the study limited its value.

The Stanford study participants only drank each type of milk for eight days. Mark McAfee explains, "It takes longer than eight days for beneficial bacteria to recolonize the gut of a severely lactose intolerant person. These good bacteria produce the lactase enzyme, which helps digest lactose." McAfee notes that more time is needed for re-colonization of beneficial bacteria in order to achieve significant improvement in the H2 test.  In fact, the H2 test did show a slight improvement in the sixteen severely lactose intolerant individuals chosen for the study.  "With more time, we would probably have seen statistically significant improvement," says McAfee.   

In December 2013, the Raw Milk Institute responded to the American Academy of Pediatrics' position against raw milk consumption by citing multiple peer-reviewed studies and internationally published research showing numerous benefits for raw milk.  The scientifically confirmed benefits include protection against asthma, allergies and eczema and improved weight gain in infants.

A 2007 pilot survey of Michigan dairy farmers and families with cow-share contracts for fresh unprocessed milk assessed 2,503 respondents. Of the 6 percent of these respondents diagnosed with lactose intolerance, 84 percent reported that they were able to drink fresh unprocessed milk without the symptoms they experienced with commercial Grade A, pasteurized and homogenized milk. This 2007 survey was commissioned by the Weston A. Price Foundation.

"Over ten million people in the U.S. now enjoy raw milk," said Fallon Morell. "Researchers need to pay attention to what this market trend is saying: many people are resolving digestion problems by a change in diet."

The Weston A. Price Foundation is a 501(c)(3) nutrition education foundation with the mission of disseminating accurate, science-based information on diet and health. Named after nutrition pioneer Weston A. Price, DDS, author of Nutrition and Physical Degeneration, the Washington, DC-based Foundation publishes a quarterly journal for its 15,000 members, supports 572 local chapters worldwide and hosts a yearly international conference. The Foundation phone number is (202) 363-4394,,



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