A Review of Studies on Seven Alternative Medicines

"Alternative medicine" is a term that has come to encompass a wide range of therapies, as well as products including herbs, vitamins, hormones and other compounds produced by the body, antioxidants, and dietary supplements.

People use these products and therapies to maintain or improve health and to help heal illness or disease. Some have been shown to contribute to health, but the claims of others haven't been supported by scientifically valid studies. Some even have the potential to cause harm.

Because many of these substances are not covered by government regulations, there are questions about their safety and efficacy. Often there is no guarantee as to the source of the product, nor that the ingredients listed on the package are precisely what's contained inside. Some studies have found products that contained far more or less than the stated amount of active ingredients.

In the United States, dietary supplements are regulated as foods, not drugs. Manufacturers do not have to provide the Food and Drug Administration (FDA) with evidence that dietary supplements are effective or safe before marketing. Because dietary supplements are not always tested for manufacturing consistency, the composition may vary considerably.

Still, alternative medicine products are becoming increasingly popular. According to the National Center for Complementary and Alternative Medicine, 36% of adults in the United States are using some form of complementary and alternative medicine (CAM). When megavitamin therapy and prayer specifically for health reasons are included in the definition of CAM, that number rises to 62%.

Some of the most popular products on the market today are black cohosh, coenzyme q10, echinacea, ginkgo biloba, glucosamine-chondroitin, melatonin, and St. John's wort. Below is a selection of recent studies and comments on each, from reliable governmental and medical resources.

If you decide to use these products, it's best to discuss them with your health care provider first. This is especially important if you take any type of over-the-counter or prescription medication, since some of the substances mentioned can affect how other medications work. In general, the use of these substances during pregnancy has not been rigorously studied, so it would be prudent for pregnant women not to take them unless they do so under the supervision of their health care provider.

Black Cohosh
Black cohosh is an herb sold as a dietary supplement in the United States. According to the National Institutes of Health Office of Dietary Supplements, it was used in North American Indian medicine for a number of problems, including gynecological disorders.

A number of studies have been undertaken to determine the value of black cohosh for menopausal symptoms, with conflicting results.

In 2001, the American College of Obstetricians and Gynecologists stated that black cohosh may be helpful in the short term (6 months or less) for women with hot flashes.

In a 2003 report in American Family Physician, author Benjamin Kligler, MD, MPH, reviewed multiple studies on the uses of black cohosh for menopausal symptoms and concluded, "Although the clinical trials on black cohosh are of insufficient quality to support definitive statements, this herbal medicine does appear to be effective in the short-term treatment of menopausal symptoms."

The National Center for Complementary and Alternative Medicine at the National Institutes of Health states: "Although preliminary evidence is encouraging, the currently available data are not sufficient to support a recommendation on the use of black cohosh for menopausal symptoms."

Black cohosh can cause stomach discomfort and headaches. Although few adverse events have been reported, long-term safety data are not available. Some believe that long-term use may adversely affect uterine or breast tissue; women with breast cancer may want to avoid black cohosh until its effects are understood.

Coenzyme Q10
Coenzyme Q10 is made naturally by the human body. It helps cells to produce energy and acts as an antioxidant. It is marketed in the United States as a dietary supplement.

Cancer
Low blood levels of coenzyme Q10 have been detected in patients with some types of cancer. As noted by the National Cancer Institute, Coenzyme Q10 has been shown to stimulate the immune system and can protect the heart from damage caused by certain chemotherapy drugs. However, no report of a randomized clinical trial of coenzyme Q10 as a treatment for cancer has been published in a peer-reviewed, scientific journal.

Cardiac Events
In a study from Molecular and Cellular Biochemistry (Mol Cell Biochem April 2003;246:75-82) referenced in the December 15, 2003 American Family Physician, author Allen F. Shaughnessy, PharmD, reports on a double-blinded, randomized controlled trial of 144 participants. The treatment group received 60 mg of coenzyme Q10 twice a day for one year, while the control group received a placebo. "Total cardiac events, including cardiac deaths and nonfatal infarction, occurred significantly less often in the treated group (24.6% vs. 45%). The outcome of cardiac deaths, nonfatal infarction, and stroke also decreased significantly (24.6% vs. 47.8%)."

According to the American Heart Association, "Less CoQ10 has been observed in some people with cardiac failure due to different causes. Much of the research has been done in patients with congestive heart failure. Some of these studies have shown positive results and others haven't. The safety and effectiveness of CoQ10 need to be further evaluated. This requires conducting well-designed clinical trials involving large numbers of patients over a long time. Until that happens, the American Heart Association cannot recommend taking coenzyme Q10 regularly."

Despite finding "favorable clinical outcomes for coenzyme Q10 treated patients" in several studies, a review by the Agency for Healthcare Research and Quality (part of the Department of Health and Human Services) concluded that "the value of coenzyme Q10 supplementation in patients with CVD is still an open question, with neither convincing evidence supporting nor refuting evidence of benefit or harm."

Echinacea
Echinacea species are flowering herbs native to North America. Echinacea is often used by consumers for the treatment and prevention of upper respiratory infections. It is one of the most commonly used herbs in the United States. Researchers funded by the National Center for Complementary and Alternative Medicine found that "echinacea (Echinacea purpurea), an herb often used to treat colds (upper respiratory infections), is not effective in young children. The researchers reported that use of echinacea from the onset of symptoms did not lessen the number of days the colds lasted or the severity of symptoms."

In a review in American Family Physician of the available studies on echinacea, author Benjamin Kligler, MD, MPH, describes it as a "safe herbal medicine" and concludes that "based on the current literature, it appears that prophylactic echinacea does not have a significant impact on the frequency, severity, or duration of upper respiratory infection. The data regarding treatment of upper respiratory infection appear to support a modest positive effect."

A July 28, 2005 article by Turner et. al. in the New England Journal of Medicine concluded that the active ingredients in a typical echinacea preparation "do not have clinically significant effects on rhinovirus infection or illness [colds]."

Ginkgo Biloba
According to Clinical Trials.gov, a service of the National Institutes of Health (NIH), ginkgo biloba has "properties proven to increase peripheral blood flow and to facilitate the relaxation of smooth muscle tissue. Its effectiveness in this regard has been demonstrated in numerous clinical trials that show gingko biloba to be highly efficient in treating peripheral vascular disorders."

The NIH SeniorHealth website notes that recent research suggests ginkgo may be of some help in treating Alzheimer's disease symptoms. It has also been used for a host of other problems, only a few of which have been studied. Since ginkgo might increase bleeding, it should not be taken by people who use blood thinners like warfarin or aspirin.

In a 2003 American Family Physician article, the authors did a thorough review of published studies on the use of ginkgo biloba for a variety of health problems. They concluded that ginkgo was "effective" in treating Alzheimer's disease and had "modest positive effects" in cerebrovascular disease, dementia, tinnitus and intermittent claudication (leg pain during exercise, a symptom of peripheral artery disease). For memory enhancement in adults without dementia, ginkgo was called "ineffective."

The Merck Manual states, "Many European studies have shown that a standardized preparation of ginkgo reduces symptoms in people with reduced blood flow to the brain or in the legs. For example, in people with peripheral arterial disease, it increased the distance that could be walked without pain. One large well-designed study in the United States indicated that ginkgo can stabilize or improve mental and social function in people with mild to moderate dementia, including Alzheimer's disease. Another study indicated that it can improve mental function in healthy older people."

Glucosamine-Chondroitin
Glucosamine and chondroitin are natural substances found in and around the cells of cartilage. Researchers believe these substances may help in the repair and maintenance of cartilage. In addition, researchers believe that glucosamine inhibits inflammation and stimulates cartilage cell growth, while chondroitin provides cartilage with strength and resilience. Currently, glucosamine and chondroitin are classified as dietary supplements.

A systematic analysis of clinical trials on glucosamine and chondroitin sulfate for treating osteoarthritis has shown that these compounds may have some efficacy against the symptoms of this most common form of arthritis. The study, by Timothy E. McAlindon, DM, and colleagues, published in the March 15, 2000, issue of the JAMA, recommends that additional, rigorous, independent studies be done of these compounds to determine their true efficacy and usefulness. The study was funded by the National Institute of Arthritis and Musculoskeletal and Skin Diseases.

Glucosamine/Chondroitin Arthritis Intervention Trial (GAIT) is the first multicenter clinical trial in the United States to test the effects of glucosamine and chondroitin for treatment of knee osteoarthritis; GAIT includes an additional study that will assess whether glucosamine and chondroitin can reduce or halt the progression of knee osteoarthritis. As of July, 2005, enrollment for the GAIT study was complete and data are being analyzed.

ConsumerLab.com selected and tested several glucosamine, chondroitin, and mixed glucosamine-chondroitin products and found problems only among combination products, four of which were low in chondroitin sulfate - an expensive ingredient. One product claimed to contain 500 mg per serving of "chondroitin sulfate complex" which ConsumerLab.com's testing showed to contain less than 90 mg of chondroitin sulfate. A second product for human use contained less than 85% of its claimed chondroitin sulfate.

ConsumerLab.com cautions consumers to be wary of supplements with ingredients that include words such as "complex," "formula," or "blend" when the weight of each component is not listed. While it may be legal for a manufacturer to use these terms, ConsumerLab.com often finds such information misleading.

Melatonin
In its natural form, melatonin is produced by the brain's pineal gland to regulate the sleep cycle. In the evening the level of the hormone in the bloodstream rises sharply, reducing alertness and inviting sleep, and in the morning it falls back, encouraging waking.

A 2004 evidence review by the Agency for Healthcare Research and Quality found that melatonin supplements, which people often take for problems sleeping, appear to be safe when used over a period of days or weeks. However, the safety of melatonin supplements used over months or even years is unclear.

While there is some evidence for benefits of melatonin supplements, for most sleep disorders the authors found evidence suggesting limited or no benefits, but say that firm conclusions cannot be drawn until more research is conducted.

The National Institute on Aging is launching an education effort urging consumers to use caution when it comes to "anti-aging" hormone supplements. None of the supplements mentioned, including melatonin, has been shown to prevent or reverse aging.

Consumers can buy melatonin over the counter, resulting in widespread use unsupervised by physicians. Part of the scientists' concern stems from the fact that research on melatonin, and other, more well-established hormone supplements, is relatively new and researchers have not completed the carefully controlled, long-term studies that are needed to show how hormone supplements affect people over time.

The use of melatonin to treat insomnia in cancer patients is under evaluation. Melatonin replacement has been shown to improve sleep in children with endocrine tumors that diminish the natural production of the hormone. Some studies in colon and brain cancer suggest the effect of melatonin on chemotherapy and on radiation therapy may be beneficial. Not enough is known, however, to assure patients on these therapies that melatonin treatment for insomnia is safe. Because the effect of melatonin on chemotherapy can vary, it is important for patients taking chemotherapy to consult with their health care professionals before using melatonin.

St. John's Wort
St. John's wort is an herb that has been used for centuries for medicinal purposes, including the treatment of depression. The composition of St. John's wort and how it might work are not well understood. According to the National Center for Complementary and Alternative Medicine, (NCCAM) there is some scientific evidence that St. John's wort is useful for treating mild to moderate depression.

St. John's wort interacts with certain drugs, and these interactions can be dangerous. It is important to inform all of your health care providers about any therapy that you are currently using or considering, including any dietary supplements. This is to help ensure a safe and coordinated course of care.

Several components of the National Institutes of Health funded a large research study to find out whether St. John's wort benefits people with major depression of moderate severity. This clinical trial found that St. John's wort was no more effective for treating major depression of moderate severity than placebo (Hypericum Depression Trial Study Group). (JAMA, 2002).

Research from NIH has shown that St. John's wort interacts with some drugs, including some used to control HIV infection. Other research shows that St. John's wort can interact with chemotherapeutic, or anticancer, drugs. The herb may also interact with drugs that help prevent the body from rejecting transplanted organs. Using St. John's wort limits these drugs' effectiveness.

People can experience side effects from taking St. John's wort; the most common include dry mouth, dizziness, diarrhea, nausea, increased sensitivity to sunlight, and fatigue.

A 2004 study reported in BMJ also noted the potential of St. John's wort to interact with conventional drugs.

Eileen Early, BA, BSN, RN
HealthLink Editor

Each year, Medical College of Wisconsin physicians care for more than 180,000 patients, representing nearly 500,000 patient visits. Medical College physicians practice at Children's Hospital of Wisconsin, Froedtert Memorial Lutheran Hospital, the Milwaukee VA Medical Center, and many other hospitals and clinics in Milwaukee and southeastern Wisconsin.