How to Identify High-Quality Herbal Supplements

From the Scripps Center for Integrative Medicine

LA JOLLA, Calif?Coinciding with the increasing number of conventional health care professionals who are now using herbs and phytomedicines, a number of different brands of ginkgo biloba, saw palmetto, and echinacea are also arriving on store shelves. As a result, identifying which herbal products have been backed by scientific research is becoming more difficult, according to Mark Blumenthal, founder and executive director, American Botanical Council, Austin, Tex, who spoke at the Scripps Center for Integrative Medicine's 3rd annual meeting at a session on Natural Supplements: An Evidence-Based Update.

"The research that is based on a lot of these products is basically research that has been characterized by one product or a few products that dominate a certain category," he explained.

Industry Regulations

The idea that the herbal market is an unregulated industry is mistaken, according to Mr Blumenthal; it is a regulated industry. "There are already good manufacturing practices that govern the manufacture and sale of herbal and dietary products, so anything that is manufactured in a pill or vitamin form for garlic or ginseng or ginger?all those manufacturing standards are the ones that are regulating food right now," he said.

In addition, at least 4 organizations have established third-party programs to test and document the baseline quality of herbs and other dietary supple-ments, including ConsumerLab.com, the National Nutritional Foods Association, NSF International, and United States Pharmacopeia.

"Some companies have started contracting with these third-party organizations to put approval seals on their products so that consumers can recognize that these products are what they say they are, and they're made under good manufacturing practices," Mr Blumenthal said.

The following summarizes the most clinically tested herbal therapies in several popular categories.

Planta Med

Kang Jang (Swedish Herbal Institute)?A total of 7 clinical trials were published in 2004 on this combination product of andrographis plus eleuthera. A review of these 7 trials (. 2004;70:293-298) concluded that Kang Jang provided better symptom relief than placebo in a total of 896 patients with uncomplicated upper respiratory tract infections. Kang Jang is not yet sold in the United States, but is expected to be available here in the near future.

"When we are looking at ways to treat upper respiratory tract infections secondary to cold and flu, here is an herb that people should not be overlooking," Mr. Blumenthal noted.

Neurology

Butterbur?The leading butterbur product is Petadolex (Weber & Weber). In Germany butterbur has been shown in several clinical trials to prevent and treat the symptoms of migraine headache. A randomized, placebo-controlled study including 245 migraine sufferers that was published in (2004;63: 2240-2244) found that it was an effective and well-tolerated preventive treatment for migraine.

Obstet Gynecol

J

Womens Health Gend Based Med

Black Cohosh? Used as a treatment for menopause, the most clinically tested product is Remifemin (Schaper ? Br?mmer), which has been available in Germany since the mid-1950s. There are >25 trials on this product alone (eg, . 2005; 105:1074-1083; . 2002;11:163-174), with evidence that it relieves menopausal symptoms. Another black cohosh product that is just entering the US market but is fairly well established in Europe is Klimadynon (Bionorica), which has a slightly different chemical profile than Remifemin, but very similar clinical trial results.

BMJ

Chast Tree Vitex Berry Extract? This herb, which comes from the seed or fruit extract of the Vitex agnus-castus tree, is used to treat acne, bleeding disorders, menopause, and premenstrual syndrome. In terms of clinical trial evaluation, the leading product in the world is Agnolyt (Madaus). More than 34 clinical trials have been conducted, including one (. 2001;322:134-137) that showed efficacy for premenstrual symptoms, but the product is not actively marketed anywhere.

Prev Med

Garlic? There are 2 leading products. Kwai (Lichtwer Pharma) has been studied in >32 trials, mostly relating to cardio-vascular (CV) health. One trial (. 2004; 39:985-991) showed that consuming 900 mg of garlic every day for 5 years actually reversed arterial plaque buildup in the femoral artery, based on Doppler ultrasound evaluation, compared with placebo. The other leading garlic product is called Kyolic (Wacanoga).

J Inflamm [Lond]

Phytomedicine

Cat's Claw?The number-one brand name is Krallendorn (Immodal Pharma). There are about 10 published and unpublished clinical trials on this product (eg, . 2005;21;2:11; . 2001;8: 267-274), with evidence of immune enhancement. Another product, C-Med (CampaMed), is manufactured in the United States.

Ginkgo?Tebonin (Schwabe) is the leading pioneer product that established this category about 30 years ago. It is sold as 2 different brands in the United States: GinkGold (Nature's Way) and Ginkoba (Pharmaton).

Drug Metab Dispos

Ginseng?Ginsana (Pharmaton) holds the distinction as the world's first standardized herbal extract. Since the 1960s, >50 clinical trials have evaluated this product (eg, . 2003; 31:1065-1071).

"We've published articles on the use of ginseng suggesting that the Western use of ginseng is underdosed, and some of the clinical trials that we've seen for athletic performance and other kinds of end points may have failed because they used 200 mg of Ginsana, or some kind of ginseng extract, which is significantly lower than the traditional use levels in Chinese medicine and the amount of ginseng used in animal pharmacology tests in China," Mr Blumenthal said. "Future ginseng studies should have 2 or 3 different levels of 400, 800, and 1200 mg/day of the ginseng extract to see if there is a dose-response relationship."

Echinacea?No one really owns the echinacea market. Most of the early clinical research used Echinacin (Madaus), which is made from echinacea purpurea, the fresh-pressed juice of the leaf of echinacea. This product is no longer available in the United States.

"This whole area of echinacea is very confusing. You've got 3 different species out of 9 different species that are in the marketplace. There are also 2 plant parts?the above-ground part (the aerial parts) and the root parts. You've got dried preparations like dried root and dried leaf, you've got alcoholic extracts, and the fresh-pressed juice or the dried sap of the juice or the sap, and then you have combinations thereof. So we have all of these different kinds of preparations from echinacea, which makes it very difficult to meta-analyze this whole area. It's a real headache," Mr Blumenthal said.

To understand how echinacea works, you have to know 3 things, according to Mr Blumenthal: What species did it come from, what part of the plant was used, and what was the dosage?

The New England Journal of Medicine

"[2005;353:341-348] had a negative trial on echinacea in July, but the fact is that they used about one third of the dosage that was recommended by the World Health Organization as being the appropriate dosage for the echinacea root. When you take one third of an aspirin, and your headache doesn't go away, is it the aspirin's fault? So the question is, if they had used more echinacea in that preparation and had used several different levels, then perhaps we could have seen if it was a dose-response relationship. Unfortun- ately, they only used one third of the normal dose level," he pointed out.

Saw Palmetto?No one really owns the saw palmetto market, the leading product, Permixon (Pierre Fabre), is not yet available in the United States. The second most popular product on the market is called Prostegutt (Schwabe), which is available in the United States.

Herz

Fortschr Med

Hawthorn? There is compelling evidence that this leaf and berry extract can safely increase cardiac output without interacting with any other drugs and without causing adverse side effects in patients with New York Heart Association class 2 heart failure. There are 14 clinical trials (eg, . 1999;24:465-474; . 1996;114:27-29) on Crataegutt (Schwabe) and Faros (Lichtwer Pharma), 2 hawthorn products sold in the United States as HeartCare (Nature's Way).

St. John's Wort? Used as a treatment for depression, the leading product is Jarsin (Lichter Pharma), which is sold as Kira (Abkit) in the United States.