Saw Palmetto Quality Issues

A berry from a palm tree native to Florida, saw palmetto (Serenoa repens or Sabal serrulata) has been a popular medicinal herb since its use by the states Seminole Tribe. It remains popular in the United States primarily as a natural remedy for benign prostatic hyperplasia (BPH) and other prostate and urinary problems. Recently, Information Resources Inc. (IRI) reported saw palmetto was the fourth best-selling herb in the food, drug and mass market channel in 2008, increasing 3.2 percent from 2007 to a total of $17.5 million in 2008 sales. According to SPINS, saw palmetto was the eighth best-selling herb in the health and natural foods channel at $8.9 million in 2008, down 4.6 percent from 2007 sales.

On the surface, increased consumer demand for saw palmetto would seem a good thing. However, when coupled with any shortage in supply or increased cost of raw materials, it is one of the drivers of the use of adulterated or even fake saw palmetto by suppliers and manufacturers.

Saw palmetto is sourced primarily from Florida, where hurricanes and other environmental factors can affect the crop. The harvest for the fresh ripe fruit of the saw palmetto plant is notoriously short, so any disruption to the crop during this time could impact the cost of raw materials for dietary supplement companies. The crop changes from year to year, said Joe Veilleux, general manager of Euromed USA. It is pretty consistent relative to the chemical content of the berries, but it can vary in the number of berries picked that are usable for saw palmetto extract or powder. He further noted the berries are picked at various stages of ripening over a two- to three-month period, but the window to pick the best berries is only about two to three weeks long.

Quality of saw palmetto raw material is a directly related to harvest timing, according to Valensa International. WHO, German Commission E and US Pharmacopeia (USP) monographs all specify that saw palmetto plant material of interest is dried ripe fruits that are dark brown or black in color, explained Sid Hulse, vice president of sales and marketing at Valensa, adding some product is made from green berries harvested early. 

Most recently, in 2006 Valensa International warned the industry of a poor saw palmetto crop due to a summer drought and the overharvesting of unripe berries. Expected price increases were pinned at 20 to 30 percent, depending on contracts. However, Valensa reported since then there have been two strong harvest seasons in recent years, and it expects no foreseeable issues on the horizon for 2009. 

That said, when price does increase and demand either stays the same or risessuch as in years of struggling harvestthe market is ripe for fraud. Greg Ris, vice president of Indena USA, said a series of hurricanes passing through Florida about five years ago severely damaged saw palmetto crops. Ris said about that time, several well-known distributors of Chinese ingredients were selling palm oil as saw palmetto, although saw palmetto does not grow in China. This practice typically escalates if there is a shortage of raw materials, Ris said, linking the hurricane-dampened berries supply to the palm oil adulteration. Other companies reported finding similar adulteration with canola, olive and coconut oils.

Watchdog group ConsumerLab.com tested a range of saw palmetto supplements from U.S. retail stores in 2003, finding several potential quality issues. While a few products contained less than the amount of saw palmetto shown in clinical trials as the effective daily dose (320 mg/d is commonly recommended), at least one product showed evidence of adulteration with undeclared oil.

During this time, palm oil was able to fool manufacturers in the United States for many reasons, including how saw palmetto products are made, regulated and marketed. Research showing saw palmetto extracts as safe and effective for BPH and prostate health almost exclusively features a saw palmetto extract standardized to 85 to 95 percent fatty acids (FAs)lauric, oleic, myristic, palmitic and linoleic acidsand several sterols. Substituting palm oil can achieve the 85 to 95 percent FA result.

Greg Zaino, president of Saw Palmetto Berries Coop of Florida, indicated the thinning of saw palmetto extract with palm, olive or other oils has become more blatant, perhaps becoming a greater threat than adulterated supply from international sources like China. Companies are putting these oils into a 320 mg soft gel and it weighs 320 mg in the end, he said, adding some of these finished products list olive oil on the label as an added ingredient, but it doesnt say how much is added. He explained one can easily find a product in a mass retail store that touts a 160 mg capsule of saw palmetto, but it has only 130 mg of actual saw palmetto in it; the rest is the olive oil or similar. People see 160mg and think it is all saw palmetto, he lamented. He further noted the studies showing benefits of saw palmetto were done using 160 mg (twice daily) or 320 mg capsules. They did not do studies on 130 mg of saw palmetto and 30mg of olive oil. According to Zaino, these products avoid using USP mark on the label and, thus, are not held to that standard. This is fine, from what Im told, he said.

Adulteration can also involve fatty acids, according to Zaino. You can buy all the FAs found in saw palmetto and make a fake tincture of it, he reported. He also struck out at spray-dried powder saw palmetto. A company will put saw palmetto extract on label, but its really spray-dried extract, not oil, he said. Spray-dried saw palmetto is 1/3 the strength of oil, and the studies are all done with saw palmetto oil extract.

Proper Testing

Instead of relying on a suppliers word or simply a certificate of analysis (C of A), manufacturers have plenty of chemistry resources that could help determine if a given supply of standardized saw palmetto is real or fake (i.e. palm oil).

The AOAC worked with Covance Labs to complete a single-lab validation of an analytical method to determine campesterol, stigmasterol and beta-sitosterol in saw palmetto raw materials and dietary supplements. The method that was validated used gas chromatography (GC), which is a very common analytical instrument, said Wendy Sorenson, study coordinator, Covance Labs. This equipment would be at most dietary supplement manufacturers laboratories. The testing would be considered moderately expensive to conduct. She further noted many different forms of saw palmetto were used in the validation to ensure it would cover a wide variety of sample types available on the market.

Beyond simply finding the right forms of the actives, Veilleux noted true saw palmetto has a unique composition of FAs, sterols and other constituents that is hard to duplicate. He said, Saw palmetto has nine major FAs in unique configuration, and these consistent ratios are published in monographs from USP.

Maged H. Sharaf, Ph.D., senior scientist at USP, noted official monographs for saw palmetto were first published by USP in 1905 and in the National Formulary (NF) in 1926. The four recent USP-NF monographs for saw palmetto and preparations were developed, then went through several revisions until they reached their current form in USP-NF 32-27 (official May 1, 2009), Sharaf reported. These monographs were supported by information, validated analytical procedures and supporting data received from several manufacturers, research centers, and growers; developed in the USP laboratories; found in literature; and communicated to USP by different monographs users.

 USP-NF standard botanical monographs, including those for saw palmetto, contain specifications as defined by the International Conference of Harmonization: a list of tests, their analytical procedures and their acceptance criteria, said Sharaf. These specifications help ensure the identity, composition, strength, quality, purity and limits on contaminants of botanical articles. USP also provides a majority of the reference materials and reference chromatograms that are required to perform the qualitative and quantitative determinations of the monographs.

To help stabilize the level of quality in saw palmetto market, Valensa offered free analysis and product profiling for any company interested in ensuring the quality of saw palmetto extractsstandardized powder and dried, ground berry powders were excluded due to known quality testing issues .

Hulse noted saw palmetto is unique in that it has a much higher natural level of free fatty acids than many vegetable oils.  One of the methods that might be used is acid value which is a measure of total acids in the oil, he said. It has also been proposed by Valensa to quantify free fatty acids by measuring total and bound (as glycerides) fatty acids via gas chromatography. A very high content of free fatty acids in the correct proportion can further indicate a genuine product. Valensa fingerprints saw palmetto extract by the ratio of the following fatty acids to lauric acid to determine product authenticity per USP standards. 

 There is an objective standard for saw palmetto that is based on years of studying the makeup of mature saw palmetto berries and extracts, the only saw palmetto product that has been shown to be safe and effective in dealing with the symptoms of benign prostate hyperplasia (BPH), Hulse said. If we want consumers to take us seriously about the issue of quality, we should use this objective standard. With this new free program, there is no reason not to deliver the best product to consumers.

However, while the GC method can be readily available and relatively easy to perform, Zaino contends the HPLC (high performance liquid chromatography) is the only way to know if someone is playing games with saw palmetto constituents. The GC method is the most forgiving method, so it is easy to fool, he said, noting with HPLC there is no fooling. The problem is everyone has GC methods, not HPLC, perpetuating a substandard method. In fact, Zaino argued if ConsumerLab.com used HPLC instead of GC, fewer products would have passed the quality testing. Similar to Valensas offer, Zaino said his company can help test products using HPLC. We have proprietary HPLC test, so we will do test it, he offered. The results can be reviewed by another lab, if the customer finds it necessary.

Another tool for supplement manufacturers with in-house labs is a pair of saw palmetto standard reference materials (SRMs) from NIST (National Institute of Standards and Technology), which collaborated with FDA, AOAC and the National Institutes of Healths Office of Dietary Supplements (ODS). Joseph Betz, Ph.D., director of the Dietary Supplements Methods and Reference Materials Program at ODS, explained the NIST SRMs are intended as laboratory proficiency materials. Saw palmetto berries and a commercial raw material extract were obtained and NIST performed a series of measurements for the compounds usually evaluated in saw palmetto (sterols, fatty acids) plus a few others, he said, adding NIST then created a C of A for the materials. The materials are NOT intended to be used as reference materials to establish botanical identity, or as models of what a high-quality saw palmetto material should look like as far as chemical composition. Rather, he said the goal was to provide a material that analysts can use to determine whether their analytical method/laboratory personnel are performing properly. In short, if a lab analyzes the NIST material for sterols and fatty acids and gets values that are substantially different than the NIST certified values, then they might wish to have a look at their methods and/or at how well the methods are being used.

Given these resources, a manufacturer can use the USP monographs as well as validated testing methods to ensure the qualityincluding indentifying the presence and ratios of constituentsof their standardized saw palmetto extract raw material. The NIST SRMs can help ensure the lab and methods used to perform these tests are working properly. With all these tools, why are threats of quality problems still in the saw palmetto market?

Veilleux highlighted the European saw palmetto market as an example of why regulation and marketing differences may ripen the U.S. market for such problems. In the European Union (EU), where saw palmetto is both wildly popular and consistently high quality, medicinal herbs some countries require a registration for saw palmetto as a medicinal product. This process involves a dossier that is more closely akin to documentation supporting drug preapproval in the United States. A dossier for saw palmetto extract can contain a range of supporting documentation, such as details on manufacturing and quality controls, the identity of the herb and its constituents, and data on toxicology, safety and efficacy, especially from clinical trials.

On the contrary, with no preapproval or clinical studies required prior to coming to market, U.S. botanical supplements, such as saw palmetto, can be focused solely on chemistry, including standardization marker compounds and/or active constituents. This enables companies to market saw palmetto products with chemical profiles that may be similar to clinically studied brands, but these products may not have any clinical evidence that their particular saw palmetto product actually works, both safely and without side effects.

If the efficacy of any given standardized saw palmetto extract may not be exclusive to its FA and sterol content, many other aspects of manufacturing such an extract need to be considered in delivering the consumer the most efficacious saw palmetto product. Betz referenced a recent paper (Biol Pharm Bull. 2009 Apr;32(4):646-50) that evaluated commercial products using an in vitro assay for this activity. The authors reported that as expected (because different companies produce their extracts in different ways), different commercial products have different potencies in the in vitro assay, he noted.

Saw palmetto extract, at the doses and FA/sterol standardization used in clinical trials, has the potential to help many consumers suffering BPH and other prostate and urinary health problems. While researchers have found certain FA and sterol constituents can limit dihydrotestosterone (DHT) by acting on receptors that affect the 5-alpha reductase enzyme responsible for conversion of testosterone to DHT, much is still unknown about how this herb ultimately improves symptoms of BPH and reproductive problems. Thus, the quality of saw palmetto products in the U.S. market will be consistently high if manufacturers not only perform simple due diligence of suppliers and chemical analyses of extracts and their constituents, but follow monographs to ensure safety and efficacy of the particular product being manufactured.