New study challenges claims these over-the-counter products break down gluten
By Amy Ratner, Beyond Celiac Medical and Science News Analyst
With names like Gluten Aid, Gluten Cutter, Gluten Defense and GlutenEase, these dietary supplements sound like they might be a valuable tool for managing the gluten-free diet. And that’s part of the problem, according to a new study from the Celiac Disease Center at Columbia University.
Despite names that seem to promise a way to prevent the damage from gluten, those who have celiac disease need to be wary of over-the-counter dietary supplements that claim to degrade gluten, the study found.
Researchers found “no scientific basis” for the claims that dietary supplements can digest the toxic components of gluten. And they worried use of the supplements could result in harm to patients who eat gluten, believing they are being protected.
“Such products do not have to be proven effective or even safe before they are introduced to the market, “said Benjamin Lebwohl, M.D., director of clinical research at the Columbia celiac center and one of the authors of the study, which was published in the journal Therapeutic Advances in Gastroenterology. “Perhaps the biggest hazard is the false sense of security these agents provide to the consumer with celiac disease who may be looking for ways to avoid trace amounts of gluten exposure.”
He noted that such a medication may one day be available and useful. “But until that day comes, commercially available glutenases are no substitute,” he said.
The researchers also found evidence via Google search data that consumers have a lot of interest in these products, likely leading to consequent use by patients with celiac disease. They called for greater Food and Drug Administration oversight of the supplements and encouraged physicians treating those with celiac disease to ask patients if they are taking them, particularly since patients increasingly get medical information from the Internet.
Supplements investigated in the study
- BioCore DPP IV
- Digest Gluten Plus
- Gluten Cutter
- Gluten Defense
- Gluten Digest
- Gluten Enzyme DG
- ProCellax DG2
- Similase GFCF
Typically, these supplements include gluten degrading enzymes, called glutenases. Researchers examined the active ingredients, declared allergen content, indications for use, claims about what the product could do, data supporting the claims and disclaimers on 14 commercially available glutenase products. Of these, 13 claimed to degrade immunogenic gluten fragments and four claimed to help alleviate gastrointestinal symptoms associated with eating gluten. Even the names of the products clearly suggest protection against gluten consumption, the study said.
“All of these claims may be very alluring to patients with celiac disease who feel restricted by the diet,” the authors wrote. “There is very little evidence, however, that these products actually do what they claim to do.” They attributed any relief patients may experience to the placebo effect or another undiagnosed digestive condition, perhaps related to carbohydrates, that benefits from the supplements.
“We show that these products have minimal published evidence of efficacy and may actually be hazardous to the patients with celiac disease who are taking them,” the study said.
Some enzymes can successfully degrade the harmful gluten amino acid sequences in the laboratory, but they don’t work in the acidic environment of the stomach.
Meanwhile, ongoing research has shown that a particular combination of enzymes has promise in successfully degrading small amounts of gluten. ImmuogenX is developing latiglutenase, a drug that has been shown to successfully break down gluten fragments and is in Phase 2 of clinical drug trials. The drug recently had disappointing results in one trial because it failed to meet a goal of reducing damage in the intestine more thoroughly than a placebo. But the company is moving ahead with additional trials because study investigators found that patients with positive celiac disease blood tests who got the highest doses of the drug showed significant improvement in some symptoms.
Additionally, KumaMax, a synthetic enzyme being developed by the University of Washington, is active under acidic stomach conditions and has high specificity for the parts of gluten that trigger the autoimmune reaction that leads to celiac disease.
All the over-the-counter dietary supplements reviewed in the study contained enzymes, with eight basing their claims on dipeptidyl peptidase IV, (DPP-IV). However, researchers said, this has limited ability to degrade gluten on its own. Some products listed types of enzymes that researchers said do not degrade gluten proteins at all.
In contrast to the claims regarding the ability to break down gluten, many of the supplements had multiple disclaimers for consumers. The most common, used on 11 of the products, noted that statements on the label “had not been evaluated by the FDA and that the product was not intended to diagnose, treat, cure of prevent any disease.” Seven said celiac disease patients should stay on the gluten-free diet while using the product and two advised them to use the product only under a physician’s supervision.
One even listed wheat, a gluten-containing grain, as an ingredient, as required by the FDA allergen labeling law when one of the top eight allergens is included.
While the FDA does require some disclaimers, it has only minimal authority over dietary supplements, which do not have to meet the same requirements as drugs when it comes to clinical testing and labeling.
Despite product warnings, researchers found evidence of considerable consumer interest in gluten-degrading supplements when measured by frequency of Google searchers. Their tally showed 3,173 searches per month based on product names and several related terms. They said this was comparable to searches for information on celiac disease in general during the period they measured.
“It is understandable that those with celiac disease desire and need alternative therapies to either replace or assist them with the gluten-free diet, “ the study said. But the authors concluded, “With the potential hazards and lack of evidence of efficacy of the glutenase products we investigated, it appears entirely inadvisable for patients with celiac disease to use the products.”