The DNA Approach to Botanicals

For many years in the food and dietary supplement industries, no ingredient group has been more scrutinized by regulators or been the subject of economic adulteration than botanical ingredients. In recent years, certain regulators have taken an extreme interest in this topic; and while we all share and applaud the goal of manufacturing products with better quality, the use—and in some cases the misuse—of cutting-edge DNA analytical techniques has made DNA science the “hot topic” in the world of quality control for dietary supplements. The specter of potentially mislabeled botanical products has raised questions about product quality and safety and led to a decrease in general consumer confidence in dietary supplements.

With this increased scrutiny, regulators have concluded, both appropriately and unjustly, that traditional botanical analysis is no longer adequate and that DNA testing is the only solution for confirming authenticity of a botanical ingredient. This technology can play an important role in quality control in the dietary supplement industry, but only when embedded in a complete quality control program and not in isolation. For example, botanical ingredients that go through an extraction process have significantly reduced DNA content, and analysis of DNA in botanicals for foods and dietary supplements can be extremely difficult and costly. When the expertise needed to properly interpret the results is absent, the data can result in wrong interpretations and lead to wrong decisions.

Why DNA Testing Can be Problematic

DNA, or deoxyribonucleic acid, is known as the genetic blueprint for building cells. Friedrich Miescher first isolated DNA in 1869, and James Watson and Francis Crick identified its molecular structure, the famous double-helix, in 1953. In the past quarter century, DNA analysis is much more accessible and can now be used for crime solving and genetic mapping, among other things.

Employing DNA testing to ingredients used in the supplement industry presents some challenges because processing techniques such as heating, grinding, or extracting botanical materials, degrades DNA quality.

Genomic sequencing quality is partially determined by the variable size of the DNA fragments, measured in units called base pairs. The largest fragment found in human genome is approximately 220 million base pairs. By comparison, a leaf has 20,000 to 150,000 base pairs. This fragment length size enables a relatively easy evaluation of DNA. However, when the leaf is ground into a powder, the fragment size in the leaf DNA sequence can be reduced. If that powder leaf is further processed, fragment size can be reduced to 100 base pairs or less. The DNA testing becomes more difficult the smaller the fragment length. Further compounding this issue is that DNA methodologies can detect the presence of ingredients in minute quantities resulting from incidental contact, but the analytical result is not quantifiable. Therefore, those minute ingredients are registered as “contaminants” or “adulterants,” and interpreting the presence of “incidental DNA” requires genetic expertise and the support of other analytical testing to make an appropriate conclusion.

Growing Pressure

Quality minded companies in the food and dietary supplement industry have been focused on making continually better products over the years, but there is still growing pressure for companies to more accurately identify product ingredients, fueled especially by instances when DNA testing has exposed adulteration or mistakes in other segments of the industry. Examples include horsemeat being sold as frozen beef burgers in Irish and British supermarkets in 2013 and issues with adulterated products like fish, wines, and olive oils.

Responding to this growing pressure, in 2015, the New York Attorney General’s office used a DNA barcoding technique to analyze select herbal supplement products. The findings showed store-branded, herbal supplement products sold by large retailers either could not be verified to contain the botanicals promised on the labels or were potentially contaminated or substituted with ingredients such as powdered rice and houseplants. Many of the limitations of DNA testing noted above were exposed as part of this investigation. GNC and NBTY eventually reached agreements with the Attorney General’s office to research DNA barcoding and other analytical techniques, implement manufacturing reforms, and update their labeling.

DNA Testing Program

In 2015, Herbalife Nutrition company focused on developing DNA test methods in-house to better understand the technology. Chemical and analytical testing are still the primary methods used to test the quality and identity of its botanicals. DNA analysis, using the correct methods, can provide fingerprint verification of each botanical source, such as differentiating between Chinese mint and peppermint. On the other hand, DNA will not detect adulterants such as brown sugar that can dilute ginseng.