And Now, The Rest of the Story of the Stanford Raw Milk, Lactose Intolerance Study
One of the things that always amazes me about the raw milk controversy is how public health and medical professionals come to definitive conclusions with little or no research basis.
A classic example involves the recent flap over whether raw milk helps counter the bloating, gas, and other symptoms of lactose intolerance among those who consume pasteurized dairy products.
A study out of Stanford University, published in the journal Annals of Family Medicine, concluded that its “data do not support the widespread claim that raw milk confers benefits in reducing the discomfort of lactose intolerance. Primary care physicians and gastroenterologists should be aware that the evidence supporting raw milk consumption remains anecdotal.”
The "data"? A study of 16 individuals with lactose intolerance—hardly more than the “anecdotal” evidence suggesting raw milk helps counter lactose intolerance.
(I actually reported the results of the Stanford study back in late 2010, when the results were first tabulated, in a Grist article.)
But before going further into the Stanford study, it is worthwhile to review some history about the association of raw milk with lactose intolerance, which is a problem in people who lack the enzyme necessary to metabolize lactose, a sugar found in milk. One theory about why pasteurized milk presents a problem for the lactose intolerant is that pasteurization destroys an enzyme present in the milk that helps in the digestion.
There wasn’t any research that I am aware of on lactose intolerance as it relates to raw milk, prior to an effort by retired pathologist Ted Beals and lawyer Steve Bemis in Michigan in 2007 and 2008. I recounted their initial survey of Michigan and Illinois cowshare members in my book, The Raw Milk Revolution: “The survey inquired into how many household members consumed raw milk, whether they had ever been told by a physician that they suffered from lactose intolerance, and, if they had, whether or not raw milk provided relief. Some 731 households completed surveys—they represented a total of 2,503 people—and, not suprisingly, 89 percent of those individuals were regularly consuming raw milk.”
Here’s what they found in the responses: “Some 155 individuals, or 6 percent, of the 2,217 regular consumers of raw milk, said they had been ‘told by a health care professional they had lactose intolerance’…And, as the researchers suspected, raw milk had provided relief to many: Of the 155 with confirmed lactose intolerance, 127 exhibited no symptoms of lactose intolerance when they deank the fresh unprocessed milk. Yes, the sample size was small, but the results were clear…” (Beals provides an account of the survey in a 2008 article.)
In 2009, not long after the Beals-Bemis results began circulating, the U.S. Food and Drug Administration came out with its take on the raw-milk/lactose-intolerance connection. The head of its dairy division, John Sheehan, was quoted in an FDA newsletter: “‘Raw milk advocates claim that pasteurized milk causes lactose intolerance,’ says John Sheehan, Director of FDA’s Division of Plant and Dairy Food Safety. ‘This is simply not true. All milk, whether raw or pasteurized, contains lactose, and pasteurization does not change the concentration of lactose nor does it convert lactose from one form into another.’
“Raw milk advocates also claim that raw milk prevents or cures the symptoms of lactose intolerance. Arguing that raw milk contains Bifidobacteria, they claim these microorganisms are beneficial (probiotic) and create their own lactase, which helps people digest the milk.
“ ‘This is not true, either,’ says Sheehan. ‘Raw milk can contain Bifidobacteria, but when it does, the bacteria come from fecal matter (animal manure) and are not considered probiotic, but instead are regarded as contaminants.’
“Drinking raw milk will still cause uncomfortable symptoms in people who are correctly diagnosed as being lactose intolerant. But worse than this discomfort are the dangers of raw milk, which can harbor a host of disease-causing germs, says Sheehan. ‘These microorganisms can cause very serious, and sometimes even fatal conditions in humans.’“
Not surprisingly, Sheehan didn’t provide a source for his contention that raw milk causes lactose intolerance to the same extent as pasteurized milk. Nor did he provide a source for his quotation of “raw milk advocates” who make the bifidobacteria claim.
In any event, based on the intriguing Beals-Bemis research (which wasn’t submitted for publication in an academic journal), and the FDA denial, the Weston A. Price Foundation, which had helped underwrite the Beals-Bemis survey, decided to back the followup study carried out at Stanford University, to explore the raw-milk/lactose-intolerance connection more deeply. Mark McAfee of Organic Pastures Dairy Co. and a few other raw milk advocates joined with WAPF in funding the Stanford study.
Some 440 people responded to Stanford’s call for volunteers suffering from symptoms of lactose intolerance from pasteurized milk. But when all was said and done, and people were eliminated for various reasons (like having taken antibiotics recently) and the hydrogen test was administered, 95% of the volunteers were gone.
Here is what McAfee concludes in a written assessment he did of the Stanford study: “It is clear that Stanford was able to clinically identify true lactose intolerance by the use of the HBT test. However, the study was not able to identify and provide reasons for the massive number of people that simply cannot drink pasteurized milk but thrive on raw milk. All of those candidates that would have exposed this data were excluded from the study. It is also true that the study showed and reported that even over a short eight days, trends to raw milk acclimatization began to appear, with HBT curves dropping. Unfortunately, the study was stopped at eight days…”
Ted Beals makes a similar observation (though not specifically commenting on the Stanford study), arguing that the problem is about difficulties people have digesting pasteurized milk, not with lactose intolerance, per se: “The bottom line is not about the diagnosis of lactose intolerance, it is about the huge number of people who are NOT drinking commercial milk because it makes them sick. And the confirmed observation that very large numbers of people who stopped drinking commercial milk because it makes them sick, have discovered on their own that drinking fresh unprocessed whole milk does not cause those objectionable symptoms and they can now resume drinking milk, as long as it is fresh. Do not forget that we observed that most of those people had a return of their symptoms if they tried drinking commercial milk again. The benefit is not about lactose intolerance, it is about more people enjoying drinking milk and having the benefits of fresh milk. The term lactose intolerance is a convenient and useful phrase that people use to describe their condition. Not unlike ‘gluten intolerance’.”
What makes the entire improbable scenario, with the conflicting results and questionable research, all the more frustrating is that the media have run with the Stanford study as the last word about raw milk and lactose intolerance. When we don’t even know that lactose intolerance is really the problem after all.
As long as I'm dwelling on conflicting research, I may as well throw in a couple more intriguing developments in the food-medicine arenas. First, there's new research indicating that all the fuss about encouraging people to reduce their saturated fat consumption was....well, misguided. All those low-fat and no-fat products that have become so popular? They were about as helpful as margarine was in an earlier day in reducing heart disease.
And now an admission from the former head of the National Institutes of Health, Dr. Bernadine Healy, that maybe, just possibly, there is a connection between vaccines and autism. After years of medical professional denials--absolutely, positively no connection--this highly credentialed medical person provides a new perspective, according to a report from CBS: "The more she dug, she says, the more she came to believe the government and medical establishment were intentionally avoiding the question because they were afraid of the answer." Where else have you seen such behavior?