Why the story on DS (Dietary Supplements) may be BS
This story came out about two weeks ago. I am chiming in a little late but the topic on dietary supplement manufacturing practices is still important. And you need to know about it.
According to the New York Times, GNC, Target, Walgreens, and Walmart have been caught selling mislabeled dietary supplements. Investigators found that four out of five of the products did not contain any of the herbs on their labels.
The story claims that up to 80% of pills that allegedly contain medicinal herbs contained little more than cheap fillers like powdered rice, asparagus, pulverized houseplants, and in some cases substances that could be dangerous to those with allergies.
Further, three out of six herbal products at Target — ginkgo biloba, St. John’s wort, and valerian root (a sleep aid) — tested negative for the herbs on their labels. But they did contain powdered rice, beans, peas and wild carrots. And at GNC, the agency said, pills contained unlisted ingredients used as fillers, like powdered legumes, the class of plants that includes peanuts and soybeans, a hazard for people with allergies.
Questioning the testing method – DNA bar coding
There are some problems with this report, though. It is worth noting that DNA barcoding has been criticized by botanical scientists who question whether this technology is an appropriate or validated test for determining the presence of herbal ingredients in finished botanical products.
DNA barcoding has strengths and limitations. DNA testing is rarely able to properly identify chemically complex herbal extracts as little or no DNA is extracted in many commercial extraction processes. Processing during manufacturing of botanical supplements can remove or damage DNA; therefore, while a DNA testing method can be useful in some cases, this method well may be the wrong test for these kinds of products.
Also, the DNA testing method does not provide information on the amounts of food contaminants found in the products. This is important because there are well-established legal thresholds that allow for trace amounts of some ingredients, say gluten, rice, pine, etc., which are not considered harmful or required on labels.
Alarming the public by saying that these substances could be dangerous to people with allergies is unnecessary; after all, there was no mention of whether DNA from these substances poses any allergic risk.
Being based on only one testing technology from only one laboratory, the NY AG results are preliminary and require further substantiation. Additional tests using microscopic analysis and validated chemical methods should be conducted to confirm the initial results upon which the AG is acting.
Questioning the tester – Professor James A. Schulte II
Of note, the AG’s office contracted with Prof. James A. Schulte II, PhD, of Clarkson University in Potsdam, New York, who employed DNA barcode technology to test the supplements. Dr. Schulte has a background in evolutionary biology and reptilian zoology, but he is not considered an expert in botany, pharmacology, or natural product chemistry — three key scientific areas related to herb and medicinal plant research.