Keeping an eye on contaminants: How to thwart suppliers of adulterated botanicals

03 Feb 2023 --- Suppliers of intentionally adulterated botanical ingredients make use of shortcomings in commonly used laboratory methods, according to a paper published by the American Botanical Council (ABC). The authors aim to raise awareness of the schemes used and urge manufacturers to establish quality control measures to authenticate their ingredients, as adulteration rates were observed between 22 and 82% for elderberry supplements.

The authors also expect adulteration to remain an issue in herbal medicine and food supplements. Demand in these industries is growing while prices of raw materials rise due to supply delays, shortages and inflation, and food supplement manufacturers are pressured to offer products at competitive prices. 

Concentrated forms of botanicals such as extracts and essential oils are also more difficult to authenticate than raw materials.

NutritionInsight speaks with Stefan Gafner, lead author of the paper and ABC’s chief science officer, who states that he hopes the publication will help “quality control and quality assurance managers to discuss the topic of adulteration with decision-makers in their company.”The authors expect adulteration to remain an issue in herbal medicine and food supplements.

“Since adulteration is a bit of a “cat-and-mouse” game, the fraudsters tend to come up with new ways to attempt detection by commonly used analytical techniques every so often,” Gafner explains. “We don’t have really good data to address the question about the frequency of adulteration.” 

“One of the reasons is that we rely on published papers to assess adulteration issues, and for most botanicals, there aren’t many papers that have documented adulteration over the years.”

Adulteration can negatively affect expected benefits from using a specific botanical ingredient as it results in variations of identity, strength and purity. Companies also need to establish the identity of the ingredients used to meet legal requirements, which is complicated for contaminated materials.

Addressing the issue 
The paper, published in the Journal of Natural Products, is based on peer-reviewed publications over the last 12 years from the ABC-AHP-NCNPR Botanical Adulterants Prevention Program. The authors hold that manufacturers need to “know the value chain and suppliers really well,” to address adulteration, says Gafner. 

Gafner states that in addition to long-standing relationships, regular supplier audits will help to increase trust.

He also warns purchasing departments to avoid shopping on price. “If the price of an ingredient is too good to be true, it’s probably adulterated.” 

It is difficult to assess how often adulteration occurs as few papers document adulteration over the years, says Gafner.

“One exception to the rule is the adulteration of ginkgo leaf extracts, for which there were over two dozen papers published over the last 20 years.”

“In this case, the extent of adulteration appears to have moved up over time, suggesting that there are more adulterated products on the market than 20 years ago. It also may point to an improvement in analytical technologies, allowing the detection of adulteration more easily.”

Extensive controls the keyThe published paper reviews commonly used schemes to adulterate botanicals. 
A sound quality control system can help to authenticate ingredients and detect adulteration. Manufacturers need to test each new batch of raw material for its identity as required by current Good Manufacturing Practices. 

“Education and awareness are the two most important criteria for identifying adulteration,” comments co-author Roy Upton, president of the American Herbal Pharmacopoeia. 

“Buyers are unaware of a lot of impurities as tests are inadequate, analysts don’t know what to look for, or adulterants are too sophisticated,” Upton details.

As the paper highlights the types of adulteration that most commonly occur, Upton hopes that it will “better inform those who want to produce quality products and inspire them to ask the right questions with regards to analytical approaches.”

Risk of adulteration 
Adulteration puts “reputable companies at a competitive disadvantage and makes them lose market share,” says Gafner, as companies selling adulterated products can offer their ingredients at a lower price. 

He adds that repurchasing rates could decrease as consumers using adulterated herbal supplements may not experience the therapeutic benefits a genuine product would provide and states that consumer interest in the botanical food supplement industry may also decrease.

“Reports on herbal product adulteration tend to make headlines in the media, leading to a loss in trust in the entire botanical dietary and food supplement industry and as a consequence to a lower interest by consumers,” Gafner adds. 

Co-author Mark Blumenthal, ABC’s founder and executive director, adds that suppliers are finding new ways to “fool or trick the prevalent analytical methods in the industry and third-party quality control laboratories.” 

By Jolanda van Hal