Identifying the Real Standardized Bilberry Extract

Categories:Health Conditions/cardiovascular, immune, eye; Herbal Ingredients; Business Strategies/quality control; Manufacturing/lab testing & methods

How ironic that an herbal extract known to support eye health fails to effectively reach consumers when companies receiving the botanical material for manufacturing turn a blind eye to adulterated supply. This is the case with bilberry, an herbal remedy dominating the natural health market for age-related macular degeneration (AMD), a leading cause of blindness in older people.

Also known as the European blueberry, bilberry (Vaccinium myrtillus) is related to blueberry but grows in single or paired formation, rather than as clusters. Another difference is bilberry flesh is a much darker red and purple than blueberries. This indicates greater anthocyanin content, the purported key to bilberry's health benefits.

Concentrating on this anthocyanin content, scientists created a standardized extract containing 25-percent anthocyanins; this is the bilberry used in many trials on ocular health, microcirculation, vascular integrity, intestinal problems, and both kidney and liver damage.

As with other botanical extracts, the standard is based on the first quality extract to the market. The first bilberry extract came from Indena in the early 1970s, utilizing the standardized method of Ultraviolet-visible (UV-VIS) spectrophotometry and reporting 25-percent anthocyanidin content on the Certificate of Analysis (C of A), as a requested specification. Christian Artaria, Indena, noted this method and reference value were subsequently adopted by the Italian Pharmacopeia and became the standard method and the reference value to describe the “quality” of a bilberry extract in the market.

According to Anthony Jacobs, BerryPharma (formerly Artemis International Europe), "25 percent is what historically could be extracted, on average, from Scandinavian Blueberries." He noted, "It would not be possible to economically reach this figure with Canadian blueberries. Most berries have quite unique and different anthocyanin profiles, and different anthocyanins have different modes of action when absorbed." Noting bilberry is unique due to the large number of different anthocyanins present in the fruit—at least 20 types—Jacobs said some of these compounds are thought to explain the anti-inflammatory benefits of bilberry intake and supplementation, as is also, perhaps, the resveratrol naturally present in the fruit's skin.

This level of concentration (100:1), coupled with the process used to manufacture a consistent, high-quality extract, have made bilberry one of the most expensive botanical extracts on the natural products market.

Jacobs said adulteration is highly profitable for cheats. "In the case of bilberry 25-percent, the price ranges from $660 (US) to $800; if you can adulterate with pigment or mulberry or black rice husks, you can bring the cost down to $50 and it is then typically sold for less than $400," he explained. "The business-to-business customer thinks that they have a bargain. However, lower prices resulted in many large contracts changing suppliers, consumer products had no active compounds, and consumers also stopped buying bilberry products—adulteration destroys the consumer repurchase chain."

The adulteration of bilberry came to the forefront in a big way in 2007, after Australian company MediHerb tested some bilberry extract it received from a supplier. Initial simple spectrometry tests showed the material met anthocyanin spec, but further analysis revealed the product was likely not entirely bilberry.

Researchers from MediHerb and several chemistry researchers from Australian universities compared a bilberry extract (claimed to be 25-percent anthocyanin) from a Chinese supplier to a reference sample (J Agric Food Chem. 2006;54(19):7378-82), using UV-VIS spectrometry as well as more advanced tests such as high-performance liquid chromatography (HPLC-DAD), UV-spectral comparison and liquid chromatography/mass spectrometry (LC/MS); they also profiled with HPTLC (high-performance thin layer chromatography).

They discovered the Chinese sample nearly matched the reference sample (as MirtoSelect, from Indena) for anthocyanins by the UV-VIS test. However, the more advanced tests revealed a more sinister differentiation. HPLC fingerprinting showed inconsistent peaks when comparing the two samples, and HPTLC started to uncover the adulterant as amaranth, a chemical red dye. Then, LC/MS appeared to definitively link the suspected fake compound in the Chinese extract to an amaranth sample.

In the end, the researchers stated the level of adulteration of bilberry extract's anthocyanin content has become sophisticated. Existing pharmacopeia testing requirements using only UV-VIS showed both samples to be similar, but only advanced testing revealed the truth behind the adulteration. The scientists, therefore, recommended companies employ advanced chromatography testing to ensure the quality and integrity of bilberry 25-percent extracts from suppliers, despite any guarantees or C of As.

Jacobs suggested supplying both a C of A and HPLC fingerprint with each shipment is a good starting place for ensuring quality bilberry extract. It advised industry manufacturers to request this basic information from suppliers, which they could then independently compare this fingerprint to a true bilberry reference fingerprint to determine if there are any adulterants present. "You will notice that reputable suppliers of bilberry have adopted this approach with their customers," he said.

Mike Barnhart, president of Veritol, a contract manufacturer of bilberry 25-percent extract, noted the high cost of bilberry and demand in the market will continue to tempt cheats into attempting adulteration. "However, enhanced understanding of bilberry chromatograms by experienced HPLC operators is generally enough to warrant further investigation if unusual patterns or lack of peak formation occur during a routine analysis."

Artaria confirmed the test methods are relatively easy to implement, but added the problem is more of ethics, regulation and enforcement. "In many markets there is no obligation for a manufacturer to analyze each batch of ingredient received," he said. "Manufacturers also make an assumption that the C of A provided with the bilberry extract is correct and true. These factors make it very difficult to uncover adulteration problems and correct them."

How broad is the problem of bilberry adulteration and what can be done about it?

Ted Waszkuc, Ph.D., method development scientist at NOW Foods, reported adulteration of bilberry extract with azo dyes such as amaranth is nothing new, having surfaced in various botanical extracts in Europe in the past. He added some azo dyes were even previously found in imported chili and curry powders, and tomato products. However, he noted FDA banned amaranth dye use in foods, drugs and cosmetics in 1976 because of concerns it may be carcinogenic.

Artaria confirmed other methods of adulterating bilberry extracts have been discovered, most commonly with different and less expensive berries like raspberry, blackberry, black currant, elderberry, etc. or extracts from the same. "As part of our ongoing activities, Indena is constantly acquiring samples of extracts on the market and these are then analyzed; bilberry has been part of these market screening efforts," he said. "These screenings help Indena to get an idea of what’s going on in the market and provide information to share with customers, but it’s difficult to say if the adulteration with amaranth dye is still a problem."

Barnhart said Veritol has been aware of past adulteration of bilberry juice with aronia in Eastern Europe, but the company has not encountered any adulterated bilberry firsthand.

Cal Bewicke, Ethical Naturals, said his company's business is mostly U.S.-focused, but his team has heard about problems in other areas outside the United States. "In general, Europe is usually freer of these types of problems, because the market has been established for a longer time, and also because Indena, who has played a key role in the development of bilberry extract quality control, is strongly based over there."

Still, as Jacobs pointed out, bilberry adulteration happens in all parts of the world. "Today, we were asked by a new European customer to take over their supply of bilberry 25-percent—approximately 1 ton per year—from a competitor, due to adulteration."

While cheaters will always surface in botanical extract markets, how does the industry improve the prevalence of high-quality bilberry extracts on the global market?

With amaranth dye outlawed for use in foods and supplements, at least in the United States (the EU is still evaluating the coal tar-based dye), offending extracts hitting the American market should be seized and penalties levied against the perpetrators.

Also, FDA's dietary supplement GMPs (good manufacturing practices) should theoretically deter and reject rogue companies trying to push through adulterated bilberry extract. This isn't utopia, though, and many expect GMPs to only have a marginal-to-moderate impact.

Artaria called GMPs a positive step toward preventing and eliminating adulteration, but the industry needs to ensure the GMPs are enforced and that, at least, each batch of ingredient received is analyzed. Adulteration issues have been identified everywhere, but they are more frequent in regions where local regulations are lacking, for example by not providing strict rules like the GMPs, or where these regulations are not enforced, for example, by regular audits to both ingredients and finished products producers."

Still such regulations require enforcement and compliance. "I don’t think government mandated GMPs will play a major role in preventing this problem," Bewicke stated. "Companies that wish to go on using cheaper adulterated ingredients will continue to use UV analysis which conveniently turns a blind eye to these adulteration methods in bilberry."

Despite the inevitable existence of cheaters and adulterators, companies and trade associations are stepping up to give the industry the right tools to operate ethically and produce high-quality bilberry extract.

Indena has been educating its customers on the complexity of this issue for many years. The trailblazing bilberry company has preached how the application of GAPs (good agricultural practices) and GMPs translates in the whole composition of the final product and not just 25 percent of an aggregated part of it that has been used to simply release the products in the past.

For bilberry, Indena released its internal HPLC methods in 2006 for the benefit of the industry, according to Artaria, who added Indena has published several papers on this issue in the Journal of AOAC International. The company has also addressed the deficiencies in labeling and compositions of many products and has actively contributed to the creation of bilberry extract monographs in the European, Italian and USP Pharmacopoeia.

"The new USP monograph on bilberry will help, since it has established an official recognized method in the United States, for the supplement industry, that is able to identify this problem," Artaria said.

The American Herbal Products Association (AHPA) also stepped up to the plate, offering a "toolbox" for industry companies needing to ensure they are receiving high-quality, unadulterated bilberry extract. Based on the research initiated by its member company MediHerb, as well as scientific testing guidance from CAMAG Scientific Inc., AHPA compiled simple tests that could help identify adulterated bilberry extracts or verify high-quality supplies. From simple pH tests for color specificity to the various forms of chromatography, this bilberry quality control toolbox, online at AHPA.org, features information on each method and includes some samples of what to look for in the results.

"Testing of bilberry and other extracts requires HPLC and UV equipment and regular practice," Jacobs said. "However, commercial laboratories offer this service at less than 150 euros—there is no excuse not to check and test each batch."

For companies such as Indena and Artemis on the frontlines of bilberry extract QC market preservation, the testing might seem routine and easy to undertake. However, in order to avoid the erosion of consumer confidence that can result from adulteration of botanicals, such as bilberry, taken for specific health concerns, all companies need to perform some regular testing, especially of product from new, unknown suppliers.

"We pre-screen all of our bilberry purchases and have individuals who are very familiar with bilberry examining the raw materials at all times," Barnhart assured, exemplifying how manufacturers without native expertise in bilberry extracts and testing can still take a high-quality approach. "Our follow-up testing involves HPLC analysis, and we confirm chromatogram patterns prior to release of any material." As for his fellow manufacturers not undertaking these simple steps, he optimistically reasoned "At some point they will go out of business, as they are discovered, and will be worked out of the market.

The Quality Control section is sponsored by Ethical Naturals; however, the company does not review or approve editorial content.