10 Top Best Selling Botanicals: What They Do

These are the top 10 best-selling botanicals in the U.S. today. Click on a botanical to learn how it is used, possible risks and adverse effects, and references.

According to the market report the top 10 best selling herbs in 2007 were, in rank order:

• Garlic
• Echinacea
• Saw palmetto
• Ginkgo
• Cranberry
• Soy isoflavones
• Ginseng
• Black cohosh
• St. John's wort
• Milk thistle

Garlic (Allium sativum)

Garlic extract is most often used in the U.S. for its ability to lower cholesterol and serum triglycerides. A more recent and rigorous study has raised questions about this claim (Gardiner et al., 2007). There is an abundance of evidence that garlic may be useful for many other purposes, including stabilizing blood pressure, enhancing immune functions, protecting against infections, and supporting cardiovascular functions.

Two recent analyses of clinical studies indicate that garlic extract may be effective for the prevention of stomach and colorectal cancers and is moderately effective in lowering serum cholesterol and triglycerides.

Possible Adverse Effects

Garlic can cause smelly breath and body odor. Other possible effects are heartburn, flatulence, nausea, and diarrhea.

Contraindications

There has been some concern about garlic and other herbal supplements hindering the ability of blood to clot and interacting adversely with commonly prescribed anticoagulant (or anti-blood clotting) medicines. However, a recent review and in vivo study (Beckart et al., 2007) found no effect on blood clotting for garlic and four other common herbal supplements in a two-week dosing study, compared with aspirin which markedly inhibited clotting. While the potential for interactions must remain recognized, the initial concerns are overstated, and the emphasis must remain on "potential."

There were several reports that garlic extracts may decrease the effectiveness of the anti-retroviral medication Saquinavir, but subsequent studies have not supported these findings.

References

Beckert, B.W., Concannon, M.J., Henry, S.L., Smith, D.S., Puckett, C.L. (2007). The effect of herbal medicines on platelet function: an in vivo experiment and review of the literature. Plastic Reconstructive Surgery, 120(7), 2044-2050.

Borek, C. (2002). Garlic supplements and saquinavir. Clinical Infectious Diseases, 35(3), 343.

Fleischauer, A.T., Poole, C., Arab, L. (2000). Garlic consumption and cancer prevention: Meta-analyses of colorectal and stomach cancers. American Journal of Clinical Nutrition, 72(4), 1047-1052.

Gardiner, C., Lawson, L., Block, E., et al. (2007). Effect of raw garlic vs. commercial garlic supplements on plasma lipid concentrations in adults with moderate hypercholesterolemia. Arch Intern Med, 167, 346-353.

Markowitz, J.S., Devane, C.L., Chavin, K.D., Taylor, R.M., Ruan, Y., Donovan, J.L. (2003). Effects of garlic supplementation on cytochrome P450 2D6 and 3A4 activity in healthy volunteers. Clinical Pharmacology & Therapeutics, 74(2), 170-177.

Thomson M, Ali M. (2003). Garlic: A review of its potential use as an anti-cancer agent. Curr Cancer Drug Targets, 3(1), 67-81.

Williams, M., Sutherland, W., McCormick, M., Yeoman, D., de Jong, S. (2005). Aged garlic extract improves endothelial function in men with coronary artery disease. Phytother Res, 19, 314-319.

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Echinacea (Echinacea purpurea; E. angustifolia; E. pallida)

Echinacea, originally a Native American remedy, has gained popularity for treating the symptoms of colds, flu, and respiratory infections. Some research indicates that echinacea has the potential to boost immune cell response, but only certain preparations of echinacea are able to do so, such as fresh pressed juice or isolated polysaccharides (Linde et al., 2006). A meta-analysis of 14 clinical studies on the effects of echinacea on the duration and severity of the common cold (Shah et al., 2007) indicated that pre-treatment with echinacea reduced the odds of developing a cold by 58 percent and reduced the average duration of the infection by 1.4 days. These and other results support the use of echinacea for prevention and treatment of the common cold.

Additional studies are taking place to explore the use of echinacea as a cancer treatment or preventive medicine. Results of a 2005 study (Miller, 2005) with mice found that daily consumption of echinacea was preventive; it extended the life span of aging mice, significantly lessened the effects of leukemia, and it extended the life span of the mice with leukemia. While the results of this mouse study are promising, it is important to keep in mind that animal studies cannot always be assumed to demonstrate clinical efficacy in humans.

Possible Adverse Effects

Echinacea is very well-tolerated.

Contraindications

People with allergies to ragweed may be allergic to echinacea. There are no reported drug/botanical interactions.

References

Barrett, B. (2003). Medicinal properties of echinacea: A critical review. Phytomedicine, 10(1), 66-86.

Carr, M.M. Nahata, M. (2006). Complementary and alternative medicine for upper-respiratory-tract infection in children. American Journal of Health-System Pharmacy, 63(1), 33-39.

Islam, J., Carter, R. (2005). Use of echinacea in upper respiratory tract infection. Southern Medical Journal, 98(3), 311-318.

Linde, K. et al. (2006). Echinacea for preventing and treating the common cold. Cochrane Database of Systematic Reviews, 25(1), CD000530.

Miller, S. C. (2005). Echinacea: A miracle herb against aging and cancer? Evidence in vivo in mice. Evidence Based Complementary Alternative Medicine, 2(3), 309.

Shah, S.A., Sander, S., White, C.M., Rinaldi, M., Coleman, C.I. (2007). Evaluation of echinacea for the prevention and treatment of the common cold: A meta-analysis. Lancet Infectious Disease, 7(7), 473-80.

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Saw palmetto (Serenoa repens)

Prostate enlargement (or benign prostatic hyperplasia, BPH) is common in men older than 50, and standardized extracts of saw palmetto berries are a safe, effective preventive measure for this condition.

A number of clinical studies indicate that saw palmetto is as effective as the pharmaceutical drug finasteride in treating benign prostatic hyperplasia.

Note that saw palmetto has not been shown to be effective for the prevention or treatment of prostate cancer.

Possible Adverse Effects

Saw palmetto is very well-tolerated with rare side-effects.

Contraindications

There are no significant contraindications or recognized drug/botanical interactions.

References

Avins, A. L., & Bent, S. (2006). Saw palmetto and lower urinary tract symptoms: What is the latest evidence? Current Urology Rep., 7(4), 260.

Bent, S. et al. (2006). Saw palmetto for benign prostatic hyperplasia. New England Journal of Medicine, 354(6), 557-566.

Boyle, P., Robertson, C., Lowe, F., Roehrborn, C. (2004). Updated meta-analysis of clinical trials of Serenoa repens extract in the treatment of symptomatic benign prostatic hyperplasia. British Journal of Urology International, 93(6), 751-756.

Buck, A.C. (2004). Is there a scientific basis for the therapeutic effects of Serenoa repens inbenign prostatic hyperplasia? Mechanisms of action. Journal of Urology, 172(5 Pt 1), 1792-1799.

Fong, Y.K., Milani, S., Djavan, B. (2005). Role of phytotherapy in men with lower urinary tract symptoms. Current Opinion in Urology, 15(1), 45-48.

Ulbricht, C., Basch, E., Bent, S., et al. (2006). Evidence-based systematic review of saw palmetto by the Natural Standard Research Collaboration. Journal of the Society for Integrative Oncology, 4(4), 170-186.

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Ginkgo

Extracts of Ginkgo are used to improve circulation in the elderly, and have shown clinical efficacy in improving memory and cognitive functions in elderly people suffering from impaired circulation in the brain. World-wide, Ginkgo is one of the most commonly used botanical medicines

Ginkgo has been well-investigated clinically, and has shown its effectiveness for a variety of conditions related to impaired circulation.

Possible Adverse Effects

Reports of adverse reactions have been extremely rare. (It may rarely cause GI upset.)

Contraindications

Can enhance bleeding risk in patients taking anticoagulants or antiplatelet drugs.

References

Birks, J., Grimley, Evans J. (2007). Ginkgo biloba for cognitive impairment and dementia. Cochrane Database of Systematic Reviews, 18(2), CD003120.

Carlson, J.J., Farquhar, J.W., DiNucci, E., Ausserer, L., Zehnder, J., Miller, D., Berra, K., Hagerty, L., Haskell, W.L. (2007). Safety and efficacy of a Ginkgo biloba-containing dietary supplement on cognitive function, quality of life, and platelet function in healthy, cognitively intact older adults. Journal of the American Diet. Assn., 107(3), 432.

DeKosky, S., Fitzpatrick, A., Ives, D, et al. (2006). The Ginkgo Evaluation of Memory study: Design and baseline data of a randomized trial of Ginkgo biloba extract in prevention of dementia. Contemporary Clinical Trials, 27, 238-253.

Gaus, W., Westendorf, J., Diebow, R., Kieser, M. (2005). Identification of adverse drug reactions by evaluation of a prescription database, demonstrated for "risk of bleeding." Methods of Information in Medicine, 44, 697-703.

Gertz, H.J., Kiefer, M. (2004). Review about Ginkgo biloba special extract EGb 761 (Ginkgo). Current Pharmaceutical Design, 10(3), 261-264.

Napryeyenko, O., Borzenko, I., GINDEM-NP Study Group (2007). Ginkgo biloba special extract in dementia with neuropsychiatric features. A randomised, placebo-controlled, double-blind clinical trial. Arzneimittelforschung, 57(1), 4-11.

Ramassamy, C., Longpré, F., Christen, Y. (2007). Ginkgo biloba extract (EGb 761).in Alzheimer's disease: Is there any evidence? Current Alzheimer Res., 4(3), 253-62.

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Cranberry (Vaccinium macrocarpon)

Cranberry juice and concentrated cranberry extracts, which contain a class of antioxidants known as anthocyanins, have recently become widely used for the prevention (and occasionally treatment) of urinary tract infections. Clinical studies have shown that it is effective, but not for all populations (Cimolai & Cimolai, 2007). The effectiveness of cranberry is thought to be related to its antimicrobial properties and possibly because it prevents bacteria from sticking to the urinary tract. In addition to its utility for treating urinary tract infections, cranberry is also used in holistic therapies that focus on the heart. Accumulating evidence indicates that cranberry, as well as other fruits rich in antioxidants, may reduce the risk of cardiovascular disease (see McKay and Blumber, 2007).

Possible Adverse Effects

As with other herbs that are known to stop blood from clotting, there is a potential for adverse interactions between cranberry juice or cranberry extracts and anticoagulant (or anti-blood clotting) medications, such as Warfarin. A review of the reported case studies, however, concluded that there was sparse evidence for a clinically relevant interaction between cranberry juice ingestion and anticoagulant medicines (Pham & Pham, 2007).

Contraindications

Because cranberry juice is acidic, it has been suggested that ingestion of large amounts may increase the risk of kidney stone formation. However, a 2005 study (Gettman et al., 2005) concluded that cranberry juice slightly increased some risk factors (by elevating levels of urinary calcium and oxalate), while decreasing other risk factors. The authors concluded that overall, cranberry does not increase the risk of kidney stone formation. Diabetics should use sweetened cranberry juice with caution to ensure that it remains within the range for glucose tolerance. Ingestion of large amounts of cranberry juice (> 3-4 L/day) can cause diarrhea and other gastro-intestinal symptoms.

References

Cimolai, N., Cimolai, T. (2007). The cranberry and the urinary tract. European Journal of Clinical Microbiology & Infectious Disease, 26(11), 767-776.

Gettman, M., Ogan, K., Brinkley, L., et al. (2005). Effect of cranberry juice consumption on urinary stone risk factors. Journal of Urology, 174, 590-594.

McKay, D.L., Blumberg, J.B. (2007). Cranberries and cardiovascular disease risk factors. Nutrition Review, 65(11), 490-502.

Pham, D.Q., Pham, A.Q. (2007). Interaction potential between cranberry juice and warfarin. American Journal of Health-System Pharmacy, 64(5), 490-494.

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Soy isoflavones

Many plants contain chemicals called phytoestrogens that have effects similar to human estrogen. One example of phytoestrogens are the isoflavones found in soy, red clover, and flaxseed.

Americans take isoflavones most commonly to treat menopausal symptoms. Although some studies question the effectiveness of isoflavones, one 2006 study noted that soy protein appears to reduce total cholesterol levels, and red clover reduces triglycerides while increasing HDL cholesterol. Overall, the study concluded that isoflavones in soy and red clover appear to have a "small but positive" effect and would be beneficial for menopausal women.

Possible Adverse Effects

Rarely, high quantities of soy or isolated isoflavones cause bowel irritation.

Contraindications

• People with allergies to soy or flax should use caution.
• There is some uncertainty about the safety of high doses in patients with breast cancer.
• Children should not be given dietary supplements that contain high levels of phytoestrogens because they may affect brain development.

References

Cassidy, A., Albertazzi, P., Nielsen, I.L., et al. (2006). Critical review of health effects of soybean phytooestrogens in post-menopausal women. Proceedings of the Nutrition Society, 65, 76-79.

Krebs, E.E., Ensrud, K.E., MacDonald, R., Wilt, T.J. (2004). Phytoestrogens for treatment of menopausal symptoms: A systematic review. Journal of Obstetrics and Gynecology, 104(4), 824-36.

Kurzer, M.S. (2003). Phytoestrogen supplement use by women. Journal of Nutrition, 133(6), 1983S-1986S.

Tempfer, C.B., Bentz, E.K., Leodolter, S., Tscherne, G., Reuss, F., Cross, H.S., Huber, J.C. (2007). Phytoestrogens in clinical practice: A review of the literature. Fertility and Sterility, 87(6), 1243-1249.

Wietrzyk, J., Grynkiewicz, G., Opolski, A. (2005). Phytoestrogens in cancer prevention and therapy-mechanisms of their biological activity. Anticancer Res., 25(3c), 2357-2366.

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Ginseng (Panax ginseng; Panax quinquifolius)

Chinese or Korean ginseng is most commonly used to increase energy and improve physical and mental performance, enhance immune response, and treat erectile dysfunction. While there have been numerous clinical studies of ginseng, most have focused on a narrow aspect of the many actions claimed for this herb.

Note: "Ginseng" has been applied as a common name to many different botanicals. Chinese or Korean ginseng (Panax ginseng) should not be confused with Siberian ginseng (Eleutherococcos senticosus) or American ginseng (Panax quinquefolius) or any of the numerous other plants sometimes (incorrectly) called "ginseng."

Possible Adverse Effects

In general, ginseng is well-tolerated, with adverse reactions largely being mild and reversible (Thompson et al., 2002). Reports of severe adverse reactions to ginseng are rare, and many have been associated with the ingestion of excessive doses, which can cause sleeplessness and high blood pressure. One citation that shows up occasionally has been largely discredited and many of the findings retracted by the authors due to poor study design (Siegel, 1979).

Contraindications

Ginseng should not be used by individuals who have acute infections, especially those involving fever, or high blood pressure. Additionally, ginseng should not be used when using large amounts of caffeine or other stimulants. Patients who are preparing for or have undergone organ transplantation should also avoid ginseng.

References

Cheng, Y., Shen, L.H., Zhang, J.T. (2005). Anti-amnestic and anti-aging effects of ginsenoside Rg1 and Rb1 and its mechanism of action. Acta Pharmacologica Sinica, 26(2), 143-149.

Kim, S.H., Park, K.S., Chang, M.J., Sung, J.H. (2005). Effects of Panax ginseng extract on exercise-induced oxidative stress. Journal of Sports Medicine and Physical Fitness, 45(2), 178-182.

Leung, K.W., Yung, K.K., Mak, N.K., et al. (2007). Angiomodulatory and neurological effects of ginsenosides. Current Medical Chemistry, 14(12), 1371-80.

Radad, K., Gille, G., Liu, L., Rausch, W.D. (2006). Use of ginseng in medicine with emphasis on neurodegenerative disorders. Journal of Pharmacological Sciences, 100(3), 175-86.

Reay, J.L., Kennedy, D., Scholey, A. (2006). Effects of Panax ginseng, consumed with and without glucose, on blood glucose levels and cognitive performance during sustained 'mentally demanding' tasks. Journal of Psychopharmacology, 0(6),771-781.

Siegel, R.K. (1979). Ginseng abuse syndrome. Problems with the panacea. Journal of the American Medical Association, 241(15), 1614-1615.

Thompson, Coon J., Ernst, E. (2002). Panax ginseng: A systematic review of adverse effects and drug interactions. Drug Safety, 25(5), 323-344.

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Black Cohosh (Acteae racemosa; formerly: Cimicifuga racemosa)

Black cohosh is commonly used to treat menopausal symptoms, especially hot flashes. Some recent studies indicate that combining Black cohosh with St. John's wort could be more effective than Black cohosh alone in treating menopausal symptoms.

Possible Adverse Effects

Black cohosh may cause mild GI upset. There are some reports of other side effects with doses higher than 160 mg/day, including nausea, vertigo, uterine contractions, and bradycardia.

Contraindications

There are no known drug/botanical interactions.

References

Briese, V., Stammwitz, U., Friede, M., Henneicke-von, Zepelin, H.H. (2007). Black cohosh with or without St. John's wort for symptom-specific climacteric treatment-results of a large-scale, controlled, observational study. Maturitas, 57(4), 405.

Chung, D.J., Kim, H.Y., et al. (2007). Black cohosh and St. John's wort for climacteric symptoms. Yonsei Medical Journal, 48(2), 289.

Geller, S.E., Studee, L. (2005). Botanical and dietary supplements for menopausal symptoms: What works, what does not. Journal of Women's Health, 14(7), 634-649.

Haimov-Kochman R, Hochner-Celnikier D. (2005). Hot flashes revisited: pharmacological and herbal options for hot flashes management. What does the evidence tell us? Acta Obstet Gynecol Scand., 84(10), 972-979.

Lieberman, S. (1998). A review of the effectiveness of Cimicifuga racemosa (black cohosh) for the symptoms of menopause. Journal of Women's Health, 7(5), 525-529.

Mahady, G.B., Fabricant, D., Chadwick, L.R., Dietz, B. (2002). Black cohosh: An alternative therapy for menopause? Nutrition in Clinical Care, 5(6), 283-9.

Taylor, M. (2003). Alternatives to HRT: An evidence-based review. International Journal of Fertility & Women's Medicine, 48(2), 64-8.

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St John's Wort

Americans commonly take St. John's wort to combat symptoms of depression.

Extracts of St. John's wort have been tested clinically and shown to be an effective alternative to some antidepressants for the treatment of mild to moderate depression. However, the herb is less effective for severe forms of depression.

Recent studies (Barnes et al., 2006; Lawvers et al., 2006) found that St. John's wort may be effective in maintaining smoking cessation. However, the results could be interpreted either way-effective or ineffective. More studies need to be done in this area. If St. John's wort proves to be effective in additional large studies, it could be considered a less expensive, and easily accessible, tool for those who wish to quit smoking.

Possible Adverse Effects

Rare effects include nausea, rash, photosensitivity, sexual dysfunction.

Contraindications

There is considerable concern regarding possible interactions of this herb with prescription medicines, and patients on any medication should consult their physicians prior to using it. Otherwise, it is generally considered safe.

References

Barnes, J., Barber, N., Wheatley, D., Williamson, E.M. (2006). A pilot randomised, open, uncontrolled, clinical study of two dosages of St John's wort (Hypericum perforatum) herb extract (LI-160) as an aid to motivational/behavioural support in smoking cessation. Planta Medica, 72(4), 378-82.

Clement, K., Covertson, C.R., Johnson, M.J., Dearing, K. (2006). St. John's wort and the treatment of mild to moderate depression: A systematic review. Holistic Nursing Practice, 20(4), 197-203.

Lawyere, S., Mahoney, M.C., Cummings, K.M., Kepner, J.L, et al. (2006). A Phase II study of St. John's wort for smoking cessation. Complementary Therapy Medicine, 14(3), 175.

Madabushi, R., Frank, B., Drewelow, B., Derendorf, H., Butterweck, V. (2006). Hyperforin in St. John's wort drug interactions. European Journal of Clinical Pharmacology, 63(2), 225.

Schulz, V. (2006). Safety of St. John's wort extract compared to synthetic antidepressants. Phytomedicine, 13(3), 199-204

Pilkington, K., Boshnakova, A., Richardson, J. (2006). St John's wort for depression: Time for a different perspective? Complementary Therapies in Medicine, 14(4), 268-81.

Ranlov, C., Mehlsen, J., Thomsen, C.F., Hedman, C., von Fircks, H., Winther, K. (2006). The efficacy of St. John's wort in patients with minor depressive symptoms or dysthymia-a double-blind placebo-controlled study. Phytomedicine, 13(4), 215.

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Milk Thistle

Milk thistle is most commonly used to support and protect the liver. It contains powerful antioxidants known as flavonolignans.

Clinical studies have confirmed its effectiveness in improving liver functions in patients with alcoholic cirrhosis and in hepatitis.

Adverse effects

No severe adverse effects reported, although some people may experience loose stools.

Contradications

Concerns have been expressed about possible interference with the metabolism of the prescription drug Indinivir, but clinical studies have found no evidence for such interference.

References

Mills, E., Wilson, K., Clarke, M., et al. (2005). Milk thistle and indinavir: A randomized controlled pharmacokinetics study and meta-analysis. European Journal of Clinical Pharmacology, 61, 1-7.

Saller, R., Meier, R., Brignoli, R. (2001). The use of silymarin in the treatment of liver disease. Drugs, 61(14), 2035-2063.

Tamayo, C., Diamond, S. (2007). Review of clinical trials evaluating safety and efficacy of milk thistle. Integrative Cancer Therapies, 6(2), 146-157.

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