(RxWiki News) Milk and dairy products can cause digestive problems for people who are lactose intolerant. Some people claim raw, unpasteurized milk doesn’t produce the same symptoms.
To evaluate claims that raw milk can reduce symptoms of lactose intolerance, researchers compared raw milk, pasteurized milk and soy milk.
Both raw and pasteurized milk produced similar digestive symptoms in those with lactose intolerance, and soy milk produced very few symptoms.
"Discuss your digestive symptoms with your doctor."
Christopher D. Gardner, PhD, and Sarah Mummah, MPhil, from the Stanford Prevention Research Center at the Stamford University School of Medicine in Stanford, CA, led this research team.
These researchers initially recruited people who had moderate to severe digestive symptoms from lactose intolerance into their study. Then the patients had a hydrogen breath test.
The test for hydrogen involves collecting a patient's breath into a container so that the hydrogen in the breath can be measured. After drinking milk, the test is repeated. If the reading taken after drinking milk is more than 12 ppm higher than the first measurement, it is an indication that the person has trouble breaking down lactose contained in the milk.
Sixteen patients who had both lactose intolerance symptoms and breath hydrogen over 25 ppm were chosen as the final participants in the study.
Patients were split into three groups and consumed either raw milk, pasteurized milk or soy milk for eight days. After eight days, the patients switched to one of the other milk forms so that by the end of the study, all participants had consumed each milk type. Participants did not know which type of milk they were drinking.
On the first day and the eighth day of drinking each type of milk, the participants drank two cups of milk. On the second day, they drank a half cup of milk. They drank more each day, until by day 7, they were drinking three cups of milk.
The research team measured breath hydrogen before each type of milk was consumed, called the baseline point, after one day of drinking and after eight days. The participants were asked to report digestive symptoms, such as cramps, diarrhea, bowel sounds or gas.
Results of the study showed that the hydrogen values were similar on days of drinking raw or pasteurized milk.
Breath hydrogen readings on the first day of drinking raw milk were an average of 117 ppm higher than baseline hydrogen reading. Average breath hydrogen readings taken the first day of drinking pasteurized milk were 79 ppm higher than baseline readings. Drinking soy milk only increased the breath hydrogen 11 ppm on the first day, compared to the reading before drinking the soy milk.
By the eighth day of drinking milk, the breath hydrogen readings were also similar between the groups of people drinking raw milk or pasteurized milk, at 79 to 80 ppm higher than baseline reading. Breath hydrogen readings after drinking soy milk were 12 ppm higher than starting measurements.
By day 7 of drinking, lactose intolerance symptoms were equally as severe, whether raw milk or pasteurized milk was consumed. The symptoms reported by people who had consumed either the raw or pasteurized milk were significantly worse than the symptoms reported by the patients who drank soy milk.
The authors cited the small number of patients in the study and short periods of time that the milk was consumed as limitations of their study.
"Among those who report intolerance symptoms because of lactose malabsorption, these data do not support the widespread claim that raw milk confers benefits in reducing the discomfort of lactose intolerance,” the researchers wrote.
This study appeared in the March/April issue of the Annals of Family Medicine.
A gift from the Weston A. Price Foundation provided funding for the study.
The authors reported no conflicts of interest.