Caffeine in your supplement: is it natural or synthetic? Why it is important to be able to distinguish between products that naturally contain caffeine and those that contain added synthetic caffeine.
It is still surprising, however, that there are caffeine-containing botanical extracts available that are fortified with synthetic caffeine and that this adulteration has largely gone unnoticed by the industry or by enforcement agencies, such as FDA or FTC. This is in spite of the legal requirement by FDA for manufacturers to label added caffeine in their ingredient statement, while caffeine from natural sources does not need to be listed (for instance, products made from tea or coffee do not need the word "caffeine" on the label). Any product containing added caffeine, even if the product also contains a natural source of caffeine, would be considered misbranded if caffeine is not listed in the ingredient label.
Caffeine is found naturally in over 60 species of plants, but only a few of these sources are sold as natural sources of caffeine in this industry: guarana (Paullinia cupana), yerba mate (Ilex paraguariensis) and kola nut (Cola acuminate). Since it is difficult to prove when these products are for tified with synthetic caffeine, some manufacturers have been able to get away with passing off a cheaper product for a more expensive one (products containing 100% naturally-occurring caffeine are more expensive to produce). There is no chemical difference between natural and synthetic caffeine, so the standard HPLC assay for caffeine only verifies the total caffeine content of the product, not its origin.
There are some ways to determine adulteration though. For some products, such as powdered herbs, close examination under a microscope may visibly show the presence of synthetic caffeine because its white crystalline appearance contrasts against a normally colored matrix. A 1998 study attempted to prove authenticity of commercial guarana products based on the ratio of methylxanthines (caffeine, theobromine and theophylline) to other naturally occurring phytochemicals, such as polyphenols. In this study, the authenticity of a number of the commercial products tested was in question due to their unexpected chromatographic profiles. However, this method may not prove authenticity of an extract since various extraction methods can potentially alter the naturally-occurring ratios of these compounds.
A German paper published in 2002 describes a more reliable technique using isotope ratio mass spectrometry to confirm whether any natural source of caffeine also contains synthetic caffeine. This procedure is based on the fact that the 13C/12C and 18O/16O ratios of synthetic caffeine are different than the ratios found in caffeine from a natural source. Five out of eleven commercial products in this study were shown to contain synthetic caffeine.
Although it is up to the supplier to guarantee authenticity of their caffeine-based products, it would be prudent for the customer to question it, especially when the price is more consistent with a natural/synthetic mixture.
references furnished upon request
By Ginny Bank
Vice President--R & D/Technical Services
About the author:
Ginny Bank is vice president, R & D/Technical Services, at RFI Ingredients, Blauvelt, NY, a supplier of innovative natural ingredients for the dietary supplement and functional food industries. She can be reached at 720-304-7335; E-mail: firstname.lastname@example.org.