You think you’re doing something good for yourself when you purchase a natural health product. After all, the product, be it a powder, pill or herbal extract, is supposed to be a safe, healthy way to deal with a host of medical concerns, from colds to hot flashes and mild depression, right?
“Not always,” says Steve Newmaster, a Canadian biology professor who led a study that found many plant-based supplements can contain substitutions, contaminants and fillers without clearly stating so on the label. For those with an allergy or celiac disease, such unexpected and unwanted ingredients could be dangerous.
Newmaster and colleagues from the University of Guelph used a process called DNA barcoding to test 44 products from 12 companies, and found that only two provided the goods exactly as advertised. Some herbal pills were diluted with unlabeled wheat, soybean or rice as cheap “fillers”. (Testing for corn was not done in this research.)
To find out more about that study and industry reaction, Allergic Living contributor Lisa Fitterman had the following email exchange with Steve Newmaster.
Allergic Living: When you talk about natural health products, what are you talking about exactly?
Steve Newmaster: Natural Health Products (NHPs) include raw powders, pills and extracts for hundreds of plant species that have medicinal value.
AL: What made you take a closer look at such products?
SN: A colleague, Dr. Robert Hanner, who uncovered considerable adulteration in the way fish products were marketed, suggested I survey NHPs. So I developed molecular diagnostic technology that could be used to test their authenticity and designed the scientific study that was conducted over the course of a year.
AL: How concerned should people with celiac disease or allergies be about purchasing an herbal product?
SN: This is a tough question, as we do not know how much wheat DNA, for example, is needed to trigger a reaction. What we do know is that some manufacturers have used fillers, including wheat and soy. Also, there may be wheat and soy contaminants on equipment used to make different products. The safest thing to do is screen for any wheat DNA, and we have developed a DNA test to do just that.
AL: Can you describe the DNA test?
SN: “DNA barcoding” is a tool used to identify species. Barcoding uses a very short genetic sequence from a standard part of the genome – the way a supermarket scanner distinguishes products using the black stripes of the UPC code. Two items may look very similar to the untrained eye, but the barcodes are distinct.
We created a DNA biological reference material (BRM) library for medicinal plant species from known vouchers – pressed plant samples – filed for future reference in Herbaria [the Harvard University database of herbs]. You can identify unknown samples by extracting DNA and matching the resulting DNA barcode sequence to that of your BRM library.
AL: Some of the companies that make natural health products say that DNA barcoding can be flawed. How do you respond?
SN: Barcoding does have limitations but there are several new molecular diagnostic tools that overcome the constraints of barcoding. Some NHP companies are now using this technology to authenticate thousands of samples and make critical changes within their respective supply chains to ensure consumers that their products are safe.
AL: Can you give readers an idea of what to watch for?
SN: There is a certification program and consumer mark called TRU-ID. Look for its mark on the product and if it is not there, let brand owners know you want them to use it. I am a scientific adviser for this program, for which a team of scientists have developed very rigorous standards for DNA testing to make sure that ingredients on the label are authentic.
It’s new biotechnology and some [herbal supplement] companies such as Nature’s Way are getting all of their product lines certified. It’s encouraging because the industry needs to take action to ensure consumers have safe and authentic products.
AL: Why would fillers and additives such as wheat and soy be used at all?
SN: They are used as both a raw bioactive ingredient as well as in the formulation for manufactured bulk [or filler]. This is a common practice in the NHP industry.
AL: Did you find unidentified plant species in the products?
SN: Yes. Senna alexandrina, a plant that contains several glycosides that interact with immune cells in the colon, was used in place of St. John’s Wort (an herb commonly used to treat mild forms of depression and anxiety). This is a serious health risk because senna, which the U.S. Food and Drug Administration approves as a non-prescription, short-term herbal laxative, can cause chronic diarrhea. cathartic colon, liver damage, abdominal pain, epidermal breakdown and blistering.
Also, studies other than our own have found other toxic species in products. In the early 1990’s, for example, a toxic herb called Aristolochia fangchi was misidentified as an anti-inflammatory agent called Stephania tetrandra. More than 100 women suffered kidney failure and many later developed cancer of the urinary system. Cases like these need not occur any longer as we can screen for toxic species using commercial DNA ID tools.
AL: Were you surprised by your results?
SN: Definitely, as I didn’t think the number [of adulterated products] would be so high. And even though our study is not large enough to have statistical accuracy in estimating the amount of adulteration in the marketplace, subsequent studies that followed have corroborated our results.
AL: What is your message for people with allergies, celiac disease and/or gluten sensitivity?
SN: Look for products that have been tested and do your homework. If something says ‘gluten-free,’ for example, make sure the claim is supported by a paper trail in which suppliers sign documents guaranteeing it. As consumers, we need to demand some real evidence our food is authentic and does not contain ingredients we are concerned about.
Don’t be shy. Send your favorite brand manufacturer or retailer a message that you demand they engage in testing to ensure that the natural ingredients in their products are authentic and do not have ingredients that you are concerned about.
There are affordable tests based on scientific method that can be easily implemented into quality control systems with the food supply chain. One example is the TRU-ID certification program, which is registered in Canada, the U.S. and the European Union.